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Pelican Technical Article:

BMW Belt
Replacement

Difficulty Level: 2
Difficulty scale: Adding air to your tires is level one
Rebuilding a BMW Motor is level ten

     This article is one in a series that have been released in conjunction with Wayne's new book, 101 Performance Projects for Your BMW 3 Series. The book contains 272 pages of full color projects detailing everything from performance mods to timing the camshafts. With more than 650+ full-color glossy photos accompanying extensive step-by-step procedures, this book is required reading in any 3 Series owner's collection. The book was released in August 2006, and is available for ordering now. See The Official Book Website for more details.
 
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Figure 3

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Figure 4

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Figure 5

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Figure 6

     One of the routine maintenance items that you should perform on your BMW is the checking and replacement of your accessory drive belts.  The belts are driven off of the crankshaft and power accessories such as the water pump, power steering pump, alternator and air conditioning compressor.  There are typically two belts on the car - one that powers the air conditioning compressor and another that powers everything else.  Both should be checked periodically (every 3,000 miles, or when you change your oil), and particular attention should be paid to the main belt.  The car can run fine without the air conditioning belt installed.

     Some of the early E30 cars use a standard v-belt design, and some of the later cars use what is known as a poly-ribbed belt (having many channels or ribs on the underside of the belt).  The poly-ribbed belt setup utilizes a spring-loaded belt tensioner pulley that provides the proper tension for the belt at all times, making adjustment unnecessary. The traditional style v-belts need to be tensioned using standard types of clamps and tensioners.

     When inspecting your belts, the one thing that you want to look for is cracks (yellow arrow - Figure 1).  If you see any cracks at all, you should replace your belts.  The cracks will usually occur on the inside of the belt (the surface that typically rides on the surface of the pulley).  With the poly-ribbed belts, this is the grooved surface.  With the v-belts, this is the surfaces on the legs of the 'V'.

     With the poly-ribbed belts, replacement is a snap.  The tensioners that hold the belt tight can be easily released using a socket and or 8 mm hex tool.  Different tensioners turn different directions, so you may have to rotate the tensioner clockwise or counter-clockwise depending upon your particular car.  The description of this process is one of those things that is difficult to describe, but very easy to do.  First, pry off the small plastic cap that covers the tensioner (green arrow Figure 1).  Then, place your tool into the tensioner and try rotating clockwise or counter-clockwise - will become immediately apparent how the tensioner releases the belt (Figure 2 and Figure 3).

     Removal of the two belts is easy - you do not have to remove the fan.  Simply release the tension on the belt from the tensioner, and then the belt should simply slide off.  Release the tension, and then you should be able to unwind the belt from the engine.  The belt should be able to be maneuvered around and through the fan - you do not need to remove the fan to swap out any of the belts (Figure 4).

     It is important to note that if your BMW has air conditioning, you will need to remove this belt first, as it typically blocks the other belt.  Another tip - if the belt is worn, simply snip it with some large tin cutters and pull it out of the car, after you have released the tension on it.

     Installation of the new belt is easy.  Simply slide on most of the new belt onto the pulleys, release the tension on the tensioner, and slide the belt onto the tensioner.  Check to make sure that the belt is securely seated in all of the pulleys.  Verify that the ribbed portion of the belt is set against the crankshaft pulley.  The proper orientation of the belt is shown in Figure 5.

     Replace any plastic caps that you may have removed from the front of the tensioner pulleys.  Now, start the car and peek in at the belts.  Verify that they are turning smoothly on all of the pulleys.

     For engines with the older-style v-belts, the procedure is nearly identical, except for the tensioning.  The alternator is mounted on a bracket that rotates and is used to keep tension on the belt.  In addition, there is a small rack-and-pinion device on this bracket that allows you to crank up the tension on the belt (Figure 6).  The first step in setting or releasing tension is to release the nut on the back of the bracket that keeps the whole assembly secure.  Do not attempt to turn the geared bolt without first releasing this nut on the rear - you will most likely damage the bracket.  With the nut released, you can now turn the geared bolt counter-clockwise, releasing tension on the belt.  Belt replacement is nearly identical to the poly-ribbed belts.

     Well, there you have it - it's really not too difficult at all.  If you would like to see more technical articles like this one, please continue to support Pelican Parts with all your parts needs.  If you like what you see here, then please visit our online BMW catalog and help support the collection and creating of new and informative technical articles like this one.  Your continued support directly affects the expansion and existence of this site and technical articles like this one.  As always, if you have any questions or comments about this helpful article, please drop us a line.

   
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Comments and Suggestions:
Marhs Comments: Hi. The plastic rim of the idler pulley is completely off but the belt still tension a bit with the engine running but with a slight noise. However on my way to the repair shop the engine oil level alert light came On and has since remained like that. I've pulled over in order not to take any risk with the slightly old 520i engine. Can the idler pulley damage cause this oil alert? very urgent please
October 13, 2014
  Followup from the Pelican Staff: If the belt is still on and the engine did not overheat, I do not see how. - Nick at Pelican Parts  
Sun Comments: I have a 96 328 i and my problem is that the car keeps overheating, but there's no leakage and coolant is not low. The belt does squeal from time to time. Do u think if I replaced the belts that the coolant will flow through the engine again and cool it down? And does any of the belts eg. serpentine, timing have anything to do with the flow of coolant?
September 16, 2014
  Followup from the Pelican Staff: A slipping belt could cause overheating, if the water pump is not turning. You may also have a leak. I would pressure test the cooling system. If the system will not hold pressure and there are no external leaks the head gasket may be faulty. - Nick at Pelican Parts  
sam Comments: Hi, I have a BMW e36 318is 1998 1.9. I need to change both the belts at the front of the engine as they both have splits. Trouble is when I came to loosening the tension on the alternator belt it would not lower. To get the belt off I ended up takin the pully off. But now I am not sure how to get the belt back on.
August 31, 2014
  Followup from the Pelican Staff: The tensioner should rotate counterclockwise to relieve the tension. Did this not work for your vehicle? - Nick at Pelican Parts  
jun Comments: how do we know if the carbon brass of alternator need to be replace
June 28, 2014
  Followup from the Pelican Staff: Usually the alternator will not charge, and upon inspection you find the brushes worn out and making poor contact with the shaft. - Nick at Pelican Parts  
jun Comments: my car is 1991 model bmw second hand w v belt and rack and pinion adjuster of alternator. ibought twice new vbelt of bmw but the problem is when i install it the adjuster is on max position it did not tension the belt properly creates serpent sound its still loos what shall i do
June 27, 2014
  Followup from the Pelican Staff: You may have the wrong length belt installed. Give our parts specialists a call at 1-888-280-7799. They can help you find the right belt. - Nick at Pelican Parts  
Enz Comments: Belt is supposed to be 5 ribs and on ac compressor it fits fine but the pulley that drives the beltattached to engine seems to only take a 4 ribs. I put the belt on and it wobbles and seems unstable is the pulley incorrect is that even possible!
June 5, 2014
  Followup from the Pelican Staff: You didn't mention what vehicle you have. The belt ribs have openings for the pulley ribs, they will be different numbers as they mate. The belt part number should be double checked if you think it is wrong. If it is wobbling and the correct belt, there may be a faulty component. - Nick at Pelican Parts  
ladyowl13 Comments: my belt keeps breaking off because my alternator pulley is not lined up with the others the belt keeps coming off in ripping I don't know what the problem in a bit
April 22, 2014
  Followup from the Pelican Staff: The alternator pulley may have come loose. I would inspect it. - Nick at Pelican Parts  
Efcporter Comments: Hello mate i have a bmw 120d 2005 reg the crankshaft pulley has a little wobble in and the belt came off the other day, i was wondering if there is anywhere to get a step by step guide to changing the crankshaft pulley?
April 15, 2014
  Followup from the Pelican Staff: We dont have that tech article. But it will be in a repair manual. Check our site pelicanparts.com for a repair manual for your vehicle. - Nick at Pelican Parts  
Static Comments: i was wondering if you knew where i might be able to procure that tensioner bracket pictured in figure 6 of this right up
Either I am not searching with the correct nomenclature or its not an easy part to find. I need to find one as the last few teeth on mine have stripped out preventing me from applying full tension. Thanks.
February 7, 2014
  Followup from the Pelican Staff: Give our parts specialists a call at 1-888-280-7799. They can help you find the right part.
- Nick at Pelican Parts
 
Dan Comments: I have a 95 325i Convertible. The belts have 78K miles, so I'm changing them even though they look ok. I don't hear any strange noises from the pulleys or the tensioners. I know if I hear the dry rattle from the pulleys, they should be replaced or just due to mileage. What about the hydraulic tensioners? Is there a way I can check them?
December 27, 2013
  Followup from the Pelican Staff: If the hydraulic tensioner returns to position smoothly after being compressed and has no signs of leaking it should be OK. - Nick at Pelican Parts  
Jose Comments: I have an 98 328i. I changed both the belts and I still have this "jingle bells" noise coming from the belt or the pulley while idle. Any suggestions?
December 12, 2013
  Followup from the Pelican Staff: Could be the tensioner or a bad pulley. Remove the belts and inspect the pulleys. See if they spin free or have play in the bearings. if ok, move the tensioner back and forth, listen for the noise. - Nick at Pelican Parts  
MarkV Comments: I have an 88 325i Convertible. I just had almost 5 k done in repairs to get this car passable for an inspection. Timing belt was one of those items. I noticed the other day that it started squealing upon start up, and then after 30 seconds or less got quiet. The next time I drove it I noticed that randomly it would start to make the same noise upon acceleration, again, randomly. Parked it and have not started it since. Thoughts on issue?
November 4, 2013
  Followup from the Pelican Staff: Sounds like the drive belts are loose, I would take it back and have them readjust them. - Nick at Pelican Parts  
dj_cherryBim Comments: I have a 2004 325i BMW, a little less than 100k mi. On monday driving home I noticed the red light come on overheating & the battery light was on. I exited the highway & noticed my power steering was very stiff. I pulled car in the garage where an awful smell was present. I let the car sit overnite upon charging battery, checking coolant, & power steering fluid. Fluid was dripping bad so assumed it is a water pump failure. Are then any other parts I should check and/or replace? I have heard possibly the serpentine/timing belts, thermostat, coolant hoses, and/or head gasket...are all these pieces needed to be replaced?
October 26, 2013
  Followup from the Pelican Staff: Check the belts, fan clutch, pressure test the cooling system for leaks, and replace all parts as needed. You also might want to scan the DME for faults, it might need a thermostat.
- Nick at Pelican Parts
 
jerry Comments: My 03 745li serpentine belt snapped suddenly and i had to pull my car home becsuse mg engine heated quickly and my steering wheel got real hard. Any ideas on why did the belt snapped it doesnt look like the belt was old at all
October 20, 2013
  Followup from the Pelican Staff: The water pump may have failed. Causing the belt to go off the groove and break. Inspect the water pump pulley for movement or lateral play. It would be a good idea to check all the pulleys for smoothness and lateral play as well. - Nick at Pelican Parts  
Claudia Comments: I am replacing both belts on my 1997 318is BTW, thanks for the awesome price and fast shipping for my belts! I tried to operate the tensioner for the A/C belt but it didn't move much. I was able to loosen the belt *slightly* when I turned the 13mm bolt clockwise, which I did for a bit using a breaker bar, but there was no "spring" to the tensioner. I ended up cutting off the A/C belt, but had NO problem removing and replacing the big serpentine belt.

So my questions are: did I turn the bolt for the A/C tensioner the wrong way? I'm concerned that I may be close to snapping off the head of the bolt. If so, I'm wondering if the tensioner itself is shot - the cover for it was gone, and it was hard to turn the bolt in either direction - feels quite different from the main serpentine tensioner. I was expecting the A/C tensioner to just "give", but it seems *almost* frozen. Thanks so much for your help!
October 19, 2013
  Followup from the Pelican Staff: There may be a locking bolt that holds the tensioer in place, if you don't have a spring loaded tensioner.

Look at the tensioner, is there a curved slot that is bolts to the engine? If so, loosen this bolt, the tensioner should move. Then you will have to tension the belt and hold it while tightening this bolt. - Nick at Pelican Parts
 
Vince Comments: I need some assistance with returning and exchanging some items I purchased.

My On-line Order Tracking number is #1381697149-616

The Mounting clips, rear windshield trim, and one Uro brand idler pulley need to be exchanged.

I made a mistake while trying to navigate your website while making my purchase.

Please let me know how to start the return/exchange process.

-Vince
October 19, 2013
  Followup from the Pelican Staff: Give our parts specialists a call at 1-888-280-7799. They can help you sort this out.

Here is a link to the Pelican return policy:

https://www.pelicanparts.com/BMW/support/ReturnPolicy.htm- Nick at Pelican Parts
 
fredd Comments: i have a 2003 325 xi and my alternator pully broke and the belt too but i found out that the expansion tank crak, i replace the two tentioners the belts and the alternator and the expantion tank now the engine is making a knowking sound the rpm goes up and down when i press the gas it feel like a misfare and the engine turns off i do not know what could the problem be now any help please
October 18, 2013
  Followup from the Pelican Staff: Is the check engine light on? Have you checked the water pump, is the bearing in it ok?
- Nick at Pelican Parts
 
grimace Comments: this article was really help full as long as you use the "L" shaped hex and star wrenchs.
October 3, 2013
  Followup from the Pelican Staff: Thanks for giving our readers the tip. - Kerry at Pelican Parts  
Des Comments: I have a 1995 BMW 318is and the cooling fan will not turn on at all, there for causing the car to over heat,What do you think the problem could be?
September 20, 2013
  Followup from the Pelican Staff: Check fuse 40 first, there are two relays for the fan all of the power to run the fan goes through the high speed fan relay, so make sure the is 12 v going through that relay, the fan is controlled by the ground signal from the temp switch to the relays. So make sure the temp switch is working. Also check to make sure the fan it self work, they are know to go bad.
- Nick at Pelican Parts
 
speedskate Comments: When you check deflection/tension on an e30 timing belt, or any belt for that matter, surely the driven side will always be under very tight tension. Would it be correct to turn crank counter clockwise to get some slack to check ? Thanks.
September 19, 2013
  Followup from the Pelican Staff: When I check the tension, I rotate the motor twice back to TDC and stop right at the mark and then check the tension and the timing marks.
- Nick at Pelican Parts
 
Kieren Comments: Hi. My BMW318IS 1995 1.9 has a problem with the cooling the cooling fan does not run at the same speed as the pulleys? I was wondering if this is because the belt has been over stretched or if there is a defect in the tentioner. There is no apparent wine or hissing coming from them. I was wondering if you have any advice on how to proceed i am in the habbit of buying and fitting parts i dont need. Many Thanks K
September 12, 2013
  Followup from the Pelican Staff: If the belts are not slipping, and the pulleys are not making noise thay are going to be ok. There is a fan clutch that kicks in as the engine gets warmer, look for leaking at the front of the fan clutch, if it is leaking replace it.
- Nick at Pelican Parts
 
luks Comments: i have an E46 with a 5hp19 gearbox the transmission oil gets too hot and the car goes on limp mode. i did a transmission overhaul and i still have the same problem. My car's radiator shroud was damaged at the time i bought the car what could be the the problem with this gearbox? i even installed an external cooler behind my radiator and still the problem is not solved please advise me on things to look at. My MAf was also changed i am running out of options as i bought the car second hand with the problem. i am spending too much on the box than i had anticipated pleeeease advise.
August 7, 2013
  Followup from the Pelican Staff: I would check the transmission for slip. Other than a restrcited cooling line or cooler, a high load on the trans would cause an overheat. Be sure the trans is adapted properly. - Nick at Pelican Parts  
Moose Comments: I have a z3 2001 looks like the fan belt shifted off the pulley and caused the plastic housing around the fan to break and caused a fluid leek any one have the same problem the pulley is now off set too.
July 28, 2013
  Followup from the Pelican Staff: You're going to have to inspect all the pulleys and see what is faulty. Start by removing the drive belt and ispecting the pulleys for looseness. The water pump or an idler pulley could be faulty. Causing the belt to misalign. - Nick at Pelican Parts  
praclacla Comments: I have a '96 318ti M edition if it matters and the belt coolant, alternator, etc - not the A/C belt came off my car and I did not check how it was placed originally while cleaning the engine top a towel got stuck. I have looked at diagrams online and it seems I set it up wrong check image, but I was not able to set it up as you have it here, I know it should be a tight fit, but it seems impossible to fit it this way...
July 23, 2013
  Followup from the Pelican Staff: Your belt is on wrong, the belt should go around the water pump, then the tensioner, then down to crankshaft. Use this photo for reference.
http://www.pelicanparts.com/BMW/techarticles/E36-Belt-Replacement/pic4.jpg - Nick at Pelican Parts
 
Luke P. Comments: When the belts are off, what is the best way to test the "health" of the pulley bearings? My engine makes a fairly loud whirring sound so I assume that one or more of my pulley bearings is on the fritz. Will I be able to spin the pulley freely with my hand if the bearings are out?
February 10, 2013
  Followup from the Pelican Staff: It can be a bit difficult to determine the condition of your pulleys when the engine is not running. Sometimes you can reach in with your hand and turn each pulley one of the time and sometimes one or more of the pulleys may not feel as smooth as the others. It's a bit of a subjective process and it's not an exact science. The typical way I use to determine if a pulleys becoming worn is to spray some lubricant or WD-40 on pulley when the engine is running. If the sound of the pulley changes and any squeaking or grinding noises go away then chances are that pulley is on its way out. Some of the pulleys are really easy to change so if you're concerned about which one is failing then it might be wise to just change them all at once it typically takes about 10 to 15 minutes per pulley. - Wayne at Pelican Parts  
tcphoto Comments: I had the water pump pulley break apart on me yesterday and the drive belt broke. This is such an easy DIY, pull the mechanical fan and give yourself room to work. There is no need to pull the dust caps on an E46, use a 5/8 socket, turn the tensioners clockwise, hold in place with an allen wrench and pull the old belts. The drive belt goes on first, make sure the ribbed surfaces on belt and pulleys mate and then release the tension and pull the allen wrench. Replace the mechanical fan and shroud and start the vehicle to insure the job is done correctly.
January 30, 2013
  Followup from the Pelican Staff: hanks for the feedback. Some E46 models do require the dust caps to be remoced, all depends on the style on tensioners utilized on the engine. usually depending on model year. - Nick at Pelican Parts  
Ove Comments: Please post a diagram of the 2006 525xi and it's tensioners
December 9, 2012
  Followup from the Pelican Staff: If we get access to one we will do just that. Thanks for the feedback. - Nick at Pelican Parts  
Shadow21914 Comments: I have a 87 325i convertible and I just had to change the alternator and belt. I noticed the power steering and AC belts were cracked too so decided to change them also. They had to come off in order for the Alternator belt to go on but I was not able to figure out how the power steering belt tightened up it dosent have the tension release you all talk about it has two bolts but nothing moves how do I tighten it up
November 24, 2012
  Followup from the Pelican Staff: The power steering pump should have an adjustment nut, loosening this will remove tension on the belt. If it will not mmove, something may be seized. - Nick at Pelican Parts  
Robert Comments: Maybe I'm waaay out of date...but I was taught that horizontal cracks in a belt were normal; it was when you saw cracks running the length of the belt that you started to worry. Was this only for V-belts, or just plain wrong?

Also, should one routinely change the tensioner, etc. while changing belts or only when they start squeaking/squealing/etc.
October 21, 2012
  Followup from the Pelican Staff: Cracks are indictive of a problem on serpentine belts. It shows the belts are dry rotted and the grovves are ready to begin to fall apart. This leads to a belt failure, which can leave you starnded.

when a tensioner is a common failure componenet, it's best to replace it before it fails, as preventive maintenance.- Nick at Pelican Parts
 
far que Comments: I have a 99 e36 M3. the Previous owner had taken off the A/C belt. He gave me a new belt with the car and said he thinks its for the A/C. Its a conti-V multirib belt # 5k829. Can you guys confirm if this belt will fit my car? Thanks in advance.
September 28, 2012
  Followup from the Pelican Staff: Give our parts specialists a call: 1-888-280-7799 They will help you figure out what the belt fits. - Nick at Pelican Parts  
trev Comments: Hi I need to do some work on my sons bmw so I found this site.
Thank you guys for making this info so clear and accurate
It will save me money and time .Give yourselves a pat on the back. cheers Trev
September 6, 2012
  Followup from the Pelican Staff: Thanks for the feedback. Glad it helped. - Nick at Pelican Parts  
Tom Comments: I have the mechanical belt tensioner with the large hex bolt in the center M43/M43TU. What direction do I turn the hex bolt to loosen and remove the pulley? Counter-clockwise same direction as when loosening the tension on the belt or clockwise?
July 5, 2012
  Followup from the Pelican Staff: We don't have that engine or tensioner set up here in the US. However, I would guess (but can't be sure) that the bolt will come off in the opposite direction of tensioner rotation / belt rotation. - Nick at Pelican Parts  
AugustHouse Comments: Thanks for the great information here. Just changed both belts on my 95 E36 and it went like a snap. I did use an allen wrench with a cheater to move the one tensioner and a 5/8 socket for the other. Worked out just fine.
June 7, 2012
  Followup from the Pelican Staff: Thanks for the feedback. Glad it helped. - Nick at Pelican Parts  
Brittany Comments: I just replaced the alternator on my '93 325IS. After starting it up, I heard a whining noise so I took a look and my belt slips off just slightly. 4 ribs on the pulley, 2 ribs slipping off towards the alternator. I resat the belt, started it back up, and have the same problem, whining and belt slippage... What did I do wrong?
April 15, 2012
  Followup from the Pelican Staff: You could have a misaligned pulley. Check that the tensioner and pulleys are all lined up. Replace what looks out of place. - Nick at Pelican Parts  
megatron Comments: on my BMW 318 i have a medal hex screw that is stripped. It wont turn ive tried all day. I just need to put my belt back on. HELP!
March 7, 2012
  Followup from the Pelican Staff: If the screw is stripped, you will have to extract it, then replace it with new. I would not leave it in place. - Nick at Pelican Parts  
Sorin Comments: In Figure 5, right in the center of the picture, there is a wheel that looks like it connects to two belts at once. The serpentine belt is the interior belt, and the A/C belt is the outer belt.

My car is a 95, but has a 92 engine in it. The wheel only connects to ONE belt, the serpentine, and has no outer area on which a 2nd belt would fit. I do have a compressor and tension wheel, and they look to match what is in Figure 5 on the bottom left, but where the A/C belt would have a 3rd wheel that it wraps around, right in the center of the picture, there is nothing but a half-length wheel that spins the serpentine belt.

Can you point me to the right part to get a double-wheel that will spin both belts? I'll also need to get an A/C belt, obviously, but that I can find on my own. But I don't know what that double pulley wheel is called, to search for it.
December 28, 2011
  Followup from the Pelican Staff: That is the crankshaft pulley, center of photo with two belts on it. - Nick at Pelican Parts  
hughbee Comments: how to get fan belt back on 2001 740i? do have to take fan out? which is tension release nut?
December 13, 2011
  Followup from the Pelican Staff: You do not have to remove the fan. Your engine utilizes two hydraulic tensioners. You will have to route the belt correctly, then release tension on the tensioner and install the belt. - Nick at Pelican Parts  
Fusion 411 Comments: Katrina, thank you for your comments on July 24, 2011 about replacing the belts on a 318i! I have a 1997 BMW 318i, and the cooling fan went out so I decided to replace the belts at the same time as I installed a new fan. The belts were just like you said. First off is the crankshaft/AC belt. The tensioner for the power steering/alternator belt is the lower one of the two small smooth pulleys for that belt. You will need a 16mm socket to rotate the tensioner counterclockwise. Put the belt on and then rotate the tensioner counterclockwise use a glove or watch your knuckles until you can get the belt around the last pulley top one then let go. It's automatic! Put the AC belt on next. You will need a No. 10 hex wrench a local auto parts store had one in a pack of 7. With the hex wrench in the matching hole in the tensioner pulley, twist counterclockwise until the tension is correct 1/4" per foot; or 1/8" per 6" of free belt, also feel it before you begin, then with your second hand use a socket to tighten the set screw that locks the pulley in place. Replacing the fan was easy. There were several things to take off shroud, air tube, and bracket, but no big deal. The hardest thing was figuring out how to unplug the electrical contact a combination of squeeze and pull. Oh, if you take the shroud and fan off first, it gives you lots of room for changing the belts.
November 25, 2011
  Followup from the Pelican Staff: Thanks for the helpful information. - Nick at Pelican Parts  
zach Comments: i need some help, I have a 95' 318ti and it has this awful loud high pitched squeal, I bought the car with it like this thinking that it was a belt or a pulley and it sounds like its comming from the tensioner pulley next to the alternator, first i replaced the lower tensioner pulley and the squeal stopped for 5 mins and then started again, then i replaced my hydraulic tensioner and it still squealed then i replaced the upper tensioner pulley that is next to the alternator and it still squeals but not as loud, It does not squeal until i get the car up to about 2000rpm, my belt seems pretty new and it does not slip, im really sick of hearing the squeal and its really obnoxious and im out of ideas on what it could be, if you have any idea or if im doing something wrong please tell me, i will put a picture up of what i have in case i have something wrong and im not seeing it, thanks
October 12, 2011
  Followup from the Pelican Staff: Remove the drive belts. Then inspect each pulley for noise or a bad bearing. If nothing is found, run the engine without the belt, but only for less than a minute (as your water pump won't be rotating). If the noise is present with the belt removed, you have to look elsewhere for the source of the noise, not at the belts. Try to isolate the noise. - Nick at Pelican Parts  
joe Comments: Is there a way to adjust the tention on the serpentine belt on the 2006 325xi?
September 23, 2011
  Followup from the Pelican Staff: 2006 model year 3-Series using an automatic tensioner. If you are having an issue, inspect the belt and the tensioner. - Nick at Pelican Parts  
Jimmy Comments: I bought a Gates belt from Oreilly Auto Parts, the it is a 1569mm, smaller than your 1555 belt that you sell. I have purchased alot of parts from your store, but this belt doesn't even fit correctly on my tensioner and going somewhere else must of been a mistake lol. I'm assuming the belt is slipping for that reason and even though they charged $35 for the belt they refuse to refund since its used and I'm pretty dang sure its the wrong size.
September 19, 2011
  Followup from the Pelican Staff: Yes indeed, that does sounds like it's about 12mm too long, that would indeed cause it to slip. $35 for the belt, I think we sell it for $15 or so... - Wayne at Pelican Parts  
FIX Comments: Thanks for this write-up! Just changed the drive and a/c belts in my 1995 325i, pretty easy stuff. While you probably don't have to take the fan off to do this job, I found it much easier without the fan so I wouldn't have to wrestle with it while getting the new belts on - I didn't have to get under the car, plus it gave me an excuse to use your fan pulley holder again!

On my car, the a/c tensioner pulley took an 8mm hex bit and the main belt tensioner pulley took a 16mm socket. I didn't have a 16mm, so I used a 5/8" socket without any problems.

One small question though - in my excitement/haste of putting everything back together, I forgot to put the dust cap back on the a/c tensioner pulley. The main belt tensioner pulley never had a dust cover. Is there any harm in driving without the dust covers? They don't seem very air/water tight anyway.
September 11, 2011
  Followup from the Pelican Staff: The bearings in the pulleys are sealed, so one would think the covers are there for aesthetics. Personally, if BMW felt the need to install them on every car manufactured, I would leave the covers on. Imagine the cost of this small part and the saving if BMW chose not to install it.- Nick at Pelican Parts  
RemitAdvice Comments: So I messed up: I tried loosening the tensioner with the rack and pinion nut BEFORE loosening the little nut in front. Not sure if I've damaged the bracket or not...this is the a/c belt btw...worst case scenario....what do i need to do to fix? Replace the bracket??
September 8, 2011
  Followup from the Pelican Staff: You may just need the adjusting bolt. I would take it apart and see what is damaged. Hard to guess at what you will need without seeing. - Nick at Pelican Parts  
Patton Comments: Thanks, I had a belt slipping on my 87 e30 with the V style belts. This showed me what I need to look for to tighten. Thanks
August 20, 2011
  Followup from the Pelican Staff: Thanks for the feedback. Glad it worked out. - Nick at Pelican Parts  
sircas Comments: I have a 1988 M3 BMW. I am replacing the drive belt. I can not find the A/C compressor belt tensioner. I have loosen the bottom bolt that swivels the A/C compressor, but no movement. What else is there to loosen to swivel the A/C compressor. Alt & Powersteering both uses the Watch Bar with a adjuster bolt!
August 17, 2011
  Followup from the Pelican Staff: You have to loosen the bolts that allow the A/C compressor to pivot. If I remember correctly, there is one at the rear of the compressor and one at the front. - Nick at Pelican Parts  
Gman Comments: Excellent site, just used available info to change belts on my daughters '95 318Ti. We are in New Zealand and when I went to purchase belts they were addament it had 3 and only believed me it had 2 when I insisted they take a look.
Easy job with those 2 tensioners so easy to release. Thanks all especially 'Katrina', we had exactly the same set-up as yours.
August 13, 2011
  Followup from the Pelican Staff: Thanks for the feedback, glad we can help. - Nick at Pelican Parts  
Kike Comments: Hi i appreciate the help this site has given me in other problems but i'm a bit stuck here i want to replace my a/c belt on my 318i but i cant find the rack-and-pinion to loosen up the tension i know you mentioned it but im a beginner and i can't take it to a shop due to me making a deal that if i can learn to fix it i can keep it
August 9, 2011
  Followup from the Pelican Staff: I have to guess at what model your vehicle is, but assuming it has an M42 engine, the A/C belt has a tensioning pulley. Remove the dust cap, then loosen thebolt and rotate the tensioner to relieve tension on the drive belt. - Nick at Pelican Parts  
Chris Comments: I bought an 87 325i. there was no a/c belt on the car and I have been trying to put one on for much longer than it should take. There is no way the belt sold to me is going on this set up. I am wondering if the bracketing is on correctly as there is very little adjustment on the compresser. Does anyone have a diagram or any words of wisdom for me?

thank you,
Chris
August 8, 2011
  Followup from the Pelican Staff: Did you loosen both bolts that allow the A/C compressor to pivit? There should be one at the rear and one at the front (going from memory). If you can get the compressor to the end stop and the belt will not fit, it may be the wrong belt. - Nick at Pelican Parts  
Katrina Comments: My boyfriend and I replaced the drive belts on my 1996 BMW 318 IS. We used this site for directions as this was our first attempt ever at replacing drive belts. Neither one of us is terribly adept at fixing cars, so this post gave us the confidence to take on the project.
First we moved the fan shroud just a black plastic cover to free up a couple more inches of space. We made a diagram of how the belt wrapped around the pulleys in detail
Removing the ac belt was such a cinch. It was fairly obvious which pulley was the tensioner. It was the smallest one with a black-gray plastic cap that we removed. It also has a smooth outer edge, unlike the other pulleys that are larger and ribbed. A small twist counter clockwise with a 13mm socket did the trick. However, the serpentine belt was trickier. There were two pulleys that both were identical as tensioner pulleys. However, it turned out to be the pulley attached to what I believe is the alternator. This required more strength. He released the tensioner and I quickly went in and pulled the belt off. It was different from the ac belt that you didn't loosen a bolt, you had to pull back to release the tension on the belts. I think we used 16 or 18mm socket on this one with a torque wrench to create more give. Then just put on the belts, and the rest was a snap! Good luck! Thanks for the confidence boost Pelican Parts! Parts were $50, mechanic wanted to $270 to fix. This job took us an hour with a some setbacks as we had no prior experience. Next time 15 minute job hands down!
July 24, 2011
  Followup from the Pelican Staff: Thanks for the feedback, glad it worked out. - Nick at Pelican Parts  
Hach Comments: why cant i find out what size belts my bmw 320i 1995 takes..
June 22, 2011
  Followup from the Pelican Staff: Give our parts specialists a call: 1-888-280-7799 They can help you find the right belts. - Nick at Pelican Parts  
kchang Comments: Do you guys have a book out that covers 5 series?
1987 528E
*does this 3 series book pertain to the 5?
June 16, 2011
  Followup from the Pelican Staff: There are some similarities, but the 5-Series is a much different vehicle. - Nick at Pelican Parts  
kchang Comments: I'm glad i found this link on here...I shop for all my 87 528E parts here...
I spent this early evening trying to figure out how to get more slack on the pulley's to get the belts on! I've already released all the tension from the rack and pinion type from the compressor and alternator...

So tomorrow i'll try and release the tensioner? hopefully I can find it now that I know what i'm looking for!
* so just pry off that cover and use possibly a 8mm Hex

thanks again
June 16, 2011
  Followup from the Pelican Staff: Yes, remove the dust cover and use an Allen to rotate the tensioner. Follow the directions in the tech article. - Nick at Pelican Parts  
bamatunz Comments: Thanks again for the write up! I thought I'd post the result of a previous owner that had destroyed the teeth on 2 out of 3 of the rack and pinion tensioners on my E34 535i ...you can see where the teeth were grinded in a circular pattern...obviously where someone did NOT release the lock nut on the back of the mount before attempting to tighten them...which is CLEARLY described in the tiny owners manual in the glove box-DOH!

http://www.searchrealestatehomesforsale.com/tensioner_worn_teeth.jpg

And both of them:
http://www.searchrealestatehomesforsale.com/both_tensioners_worn.jpg

Lucky for me the drive belt was not replaced by him, so the mount was in tact.
June 4, 2011
  Followup from the Pelican Staff: Thanks for sharing the photos. These parts wear out quite a bit whether people release the rear nut or not. It seems the continued maintenance and use of that area of teeth is the issue. - Nick at Pelican Parts  
Traikun Comments: I have an 85 E30 that I'm doing the timing belt on. I'm stuck on the tensioner for the power steering pump. I've loosened every single bolt that I can find, and the tensioner will not loosen it. I've tried clockwise and counter clockwise, and the tensioner gear just seems to spin in place. It's almost as though the bolt holding it doesn't fill the space, and the gear pushes out of the way. Is there something I've missed? How many mounting bolts do I need to loosen?
June 4, 2011
  Followup from the Pelican Staff: Check and see if you missed the bolt at the rear. If all the bolts are loose, the pump may be stuck to the bracket. - Nick at Pelican Parts  
bmwracer Comments: I finally changed out the tensioner pulley... And with no drama.

The bolt #10 in the image I posted previously for the pulley IS a standard right-hand thread.

Whew. :
April 21, 2011
  Followup from the Pelican Staff: Thanks for the feedback and additonal information. - Nick at Pelican Parts  
bmwracer Comments: I want to just change the pulley on the hydraulic tensioner and not the entire tensioner assembly.

How do I loosen the hex bolt #10 in the image to remove the pulley?

Does the hex bolt have the standard right-hand thread clockwise to tighten, counterclockwise to loosen or is it a left-hand thread?

When I try to loosen the hex bolt counterclockwise the entire tensioner assembly moves as well and I don't want to really crank on it for fear of damaging the tensioner by over-compressing it.

Do I have to use something to keep the tensioner assembly from moving or do I not have to worry about over-compressing the tensioner?

April 5, 2011
  Followup from the Pelican Staff: I'm pretty sure you can just crank on it counter clockwise and it will come off. If you're unsure, then you might consider removing the tensioner from the engine, and then removing the wheel while it's secured in a vice on your workbench. - Wayne at Pelican Parts  
Ruben7 Comments: Hello there. I have a 1993 318i. Today my car overheated and the coolant reservoir started releasing vapor, at the same time, my steering got really hard to turn at low speeds. I went to check the engine and 1 small belt was hanging freely by a single pulley, it came right off, not broken or anything.

There are 3 belts in total right? The long main belt, then another for the water pump/radiator fan, and the last one for the A/C, right? I ask because I only count 2, I'm missing the one that turns the radiator fan. I'm guessing it snapped and I lost it somewhere while driving.
March 28, 2011
  Followup from the Pelican Staff: There was a major change for cars in 12/93, I want to make sure that we're talking about the same thing. I'm going to copy this question over to the forums, if you can post a photo of the front of your engine, then that would help confirm what you have.- Wayne at Pelican Parts  
chris Comments: Hi, great website.

I get this whirring/frequency type noise when i start the car, it doesnt seem to get louder or change pitch when driving. also it goes away in about 30s-1m of warming up the car. could this be the AC belt? thank you

sorry i should add that its a 97 328is
March 22, 2011
  Followup from the Pelican Staff: It's nearly impossible to diagnose over the Internet, but if you think it might be the AC or the other belt, you can remove it and run the car for a little bit to check - Wayne at Pelican Parts  
freddy Comments: My 2004 BMW 325Xi is making a chirping noise and I'm not sure whether it is a pulley or the belt? because the noise is louder when I'm parked and it softens when I'm driving. What should I do?
March 20, 2011
  Followup from the Pelican Staff: You might want to try spraying some auto parts store belt dressing on the belt and see if that makes the noise go away. If yes, it's the belt. If no, then it's most likely a pulley or bearing from one of your devices on the engine. - Wayne at Pelican Parts  
Ishmael Comments: I have a 99 e46 and recently on startup i heard a strange screeching/squeeling noise under the hood. i couldnt identify the issue. the noise got louder wit applied gas. I drive forward a few feet and heard a loud lash in the engine which turned out to me the Protection Cap for the Drive Belt Deflection Pully off and on the floor.

Unfortunately on reverse i rolled over the cap and broke it. Shockingly i throw water in the area the noise was coming from and the noise went away i guess until the belts were dry again.

Checked my Coolant and noticed it was extremely low so i topped it up and preceeded to the mechanic wher i discovered that all the coolant had "Poured out".

The mechanic informed me that the Coolant Expansion tank was leaking the coolant and the noise that i was getting not at the time when i was at the shop, that it is the belts that need changing and the tensioner.

I also discovered that i had an oil leak from the valve cover gasket which MAY have leaked onto the belts.

I am considering DIY for these fixes as his price just for labor alone was rediculous. My main question is, for the noise issue, would it be as simple as replacing the Cap that fell off and how would i know if i really need to change the tensioner?

What is the best order to do these task, cuz it seems like i would be in the hood all day if i choose to DIY. I do street parking unfortunately!!
March 15, 2011
  Followup from the Pelican Staff: Lots of stuff here. I can't comment specifically on how long it would take, as I'm not fully aware of your skill level. However, simply replacing the dust cap on the idler pulley will not make the noise go away. It sounds like it's a failing bearing, and you need to spray some WD-40 or similar substance in there to find the source of the squeeling. - Wayne at Pelican Parts  
Rman Comments: It was actually easy. I needed at 18 in breaker bar and it made the process a breeze change the 2 pulleys and the belt in 30 minutes... Tools needed, T-55 torx drive, E-14 torx socket, breaker bar, 16mm socket and ratchet.....
March 15, 2011
  Followup from the Pelican Staff: Thanks for the feedback and additional information. - Nick at Pelican Parts  
rman Comments: Hello, how do you release the tensioner on an 325i E90 3L. There is a torx 55 on the tensioner and if you remove the pulley cover there is a T-50 I think..... The thing wont budge using the T-55 which is right next to the main bolt that attaches the tensioner to the block.
March 8, 2011
  Followup from the Pelican Staff: Sorry, I'll have to admit I have limited experience so far with the modern E90 cars... - Wayne at Pelican Parts  
Mythiniel Comments: Isn't this site useful?

I'm considering replacing my partners V-belt on her 1991 E36 318i M40 since it's started squealing, but I don't know whether or not it's the tensioner - Did the M40 have a spring loaded tensioner?
February 18, 2011
  Followup from the Pelican Staff: That engine should have the rack-and-pinion style tensioner shown in Figure 6 above. - Wayne at Pelican Parts  
Mike Comments: This 'how to' uses an 8 mm hex on the tension pulley, some other writeups on the internet use a T50 torx. If these are not working on your tension pulley, try a 16 mm socket. This worked for me. I also suggest a 'come along' type pipe on the socket just to add some leverage in moving that tension pulley when trying to fit the belt over the last pulley.
February 4, 2011
  Followup from the Pelican Staff: Thanks for the feedback and additional information. Greatly appreciated. - Nick at Pelican Parts  
gabriel Comments: Should I care about torque at all?
January 5, 2011
  Followup from the Pelican Staff: There's no tightening involved with the belt - the idler pulley automatically adjusts for tension changes, so you don't need to tighten anything. - Wayne at Pelican Parts  
Smithermoose Comments: I have a 2001 540i, I'm replacing the fan belt and I'm having trouble releasing tension to slip the new belt on.I have looked at a few videos and read lots of DIY forums and none pertain to my set up. Some say use an 8mm hex key but my tensioner pulleys have a torx head? I do know it has the small pistons on the tensioner set up but I'm confused, how and what do I do? Thanks for your help.

December 27, 2010
  Followup from the Pelican Staff: The pullies should have plastic covers on them - the first thing you need to do is to remove the cover. Then you need to figure out which one is the tensioner and which ones are simply the idler pullies. I'm out of the office right now, and unfortunately, I don't have my books here to post a pic. The tensioner should either be the hex style that you mention, or it indeed may be slightly different. I don't think it has a torx fastener on it though - I'm almost certain you're looking at an idler pulley there, not the tensioner. - Wayne at Pelican Parts  
blaze Comments: I have a 95 BMW 325i it is making a knocking noise around fan pulley is it a bad pulley or.belt the fan can be moved back and forth slightly seems loose
November 20, 2010
  Followup from the Pelican Staff: It may be just that the fan is loose, or a fan blade may have been chipped, or the water pump bearings are failing. The fan is attached to the water pump - I would probably pull the pump and take a closer look. - Wayne at Pelican Parts  
Chris95m3 Comments: To Carlsbad, Unfortunately I had the same thing happen but my belt broke due to me installing belt wrong side of one pulley. Anyway, The parts water pump, both belts, new tstat and o ring all from pelicanparts.com came out to 107 shipped. They have a write up for it also and its not a difficult job. Shouldn't take more than 2-3hrs , so look for the water pump write up, the coolant flush /tstat install write up and this belt write up.
November 3, 2010
  Followup from the Pelican Staff: Thanks for the information. Glad we could help get you the right parts and help with the installation. - Nick at Pelican Parts  
Carlsbad Comments: It was indeed the water pump plus the drive belt needs to be replaced. Do you happen to know the cost & hrs to replace a water pump, coolant 1 gallon & drive belt? Txs
October 31, 2010
  Followup from the Pelican Staff: Sorry, I don't. I would call around to a few shops and inquire. - Wayne at Pelican Parts  
bottletop Comments: iv got a p reg 318ti + its just started to make a screechine noise like the fanbelts loose but when the cars running stood still its like its not ticking over right can you help
October 31, 2010
  Followup from the Pelican Staff: I would spray some belt dressing on it and see if it still makes the noise. Then you know if it's the belt or not. - Wayne at Pelican Parts  
Carlsbad Comments: Thanks Staff. I must have not been clear but the coolant completely went all over the street. Plus, when we went to fill it; it just drained right out. So, what belt would have broken? Because there is a belt that snapped or hanging around the fan...three people who looked at it also saw the belt around the fan??? Txs
October 31, 2010
  Followup from the Pelican Staff: The fan is driven by the fan clutch which is indeed attached to the water pump, which is driven by the belt. Sorry for not being clear. It's more important to have the water pump running than the fan - that is probably what caused the overheating. If coolant is leaking out, then you probably have a blown hose or something like that? - Wayne at Pelican Parts  
Carlsbad Comments: I have a 1995 BMW that the fan belt broke. What I'm wondering if the head gasket will need to be replaced if that happens? The steering got stiff then the car started making loud noises. When I pulled over about two blocks their was a trial from the coolant. The tow guy said it wasn't the engine but from the sounds of it; the head gasket might need to be replaced.

The warning signs previously had been coming on since April but I've taken it 3 times to 3 mechanics, & they all said they couldn't find anything wrong. That it's more then likely was a faulty wiring or electrical issues.

Was it wear or tear, could something cause the belt to break and what kind of damage might have occurred? Thank you.

Meaning, I can't tell when there's a real issue with my car.

October 30, 2010
  Followup from the Pelican Staff: If you're losing coolant, you will see a drop in the level in the tank. Your car doesn't have a belt-controlled fan either, but the water pump is indeed powered by the belt. I would just keep a close watch on the coolant level, and see if you're losing coolant anywhere. - Wayne at Pelican Parts  
Alvin Wong Comments: First of all, great write up. I just have a question about installing the poly-ribbed belts on an E36. When the belts are back on, is adjusting the tension on the belts necessary? Or does it automatically apply tension? Thanks!
October 24, 2010
  Followup from the Pelican Staff: Good question. The spring-loaded tensioner pulley provides uniform and accurate tension once you install the belt. The 318 and early cars have a ratcheting system that you need to turn to adjust tension though (as shown in the article, Figure 6). - Wayne at Pelican Parts  
Bill Comments: Thank you, Wayne, for your prompt reply. The serpentine belt is in good condition. No single crack was seen. I also tested the idler pulleys and found their conditions to be fine, i.e., it is not creating any sound at all when I tried to spin them with my hand. Please note that there is no sound if the vehicle is parked with its engine running. I still hear the screeching sound from time to time when the vehicle is moving. The sound goes away if I accelerate a bit or when I press the clutch pedal to shift to a lower gear. The sound can be heard after my car has travelled after 30 to 45 minutes on the city road. Thank you in advance for your advice and more power to you.
September 26, 2010
  Followup from the Pelican Staff: When I have issues like these, I typically get a can of WD-40 and spray it at every moving part in the engine compartment to see if I can locate the noise. Much more difficult when the noise is only happening at speed though. I still think what you're describing sounds like a slipping belt. It's cheap and easy to replace the belt, I would start there. - Wayne at Pelican Parts  
Bill Comments: I hear screeching/squeeling sound under the hood if my car starts to slow down or going to idle. It happens right after the peak speed was reached but if i press the clutch pedal the noise goes away. Is the belt loose on the clutch? my unit is bmw e46 2002 manual transmission. thanks.
September 22, 2010
  Followup from the Pelican Staff: There is no belt on the clutch, but the operation of the engine is probably affecting the drive belt. I would replace the belt first, and then see if the noise continues. - Wayne at Pelican Parts  
Dibby Comments: Ive got BMW 3.16i 1993 It has 2 belts 1 to the alternator from Not sure could be water pump?Please adviseand 1 belt drives the power steering.Car Doesnt have Air Cond.What is the part number for the alternator belt? How do I take it off to replace? Do I need to take off power steering belt and the radiator fan? Thanks
September 16, 2010
  Followup from the Pelican Staff: That's a Euro car, it's a bit different than the ones here in the states. I think that the procedure is almost the same though as detailed in the article. If you have another secondary belt blocking the way, then you indeed need to remove it first to get to the one behind it. - Wayne at Pelican Parts  
Adam Comments: What size socket do I need to remove the engine belt on a 2000 BMW 328i?
September 12, 2010
  Followup from the Pelican Staff: Sorry for the confusion everybody, I updated the article, the correct size is 8mm. - Wayne at Pelican Parts  
GJIMM Comments: Think i'm on the right track here, would the drive belt be the same as the timing belt? I have a 2003/4 320i and when pressing the accelarator it feels very ropey, its as though I can feel the tension in a cable thats wearing very fine. Engine noise does seem to be pretty loud, but thats kind always been like that. Someone said its sounds like the timing belt, there's around 74000 on the clock. Any help is greatly appreciated, or maybe pointing me in the right direction.
August 16, 2010
  Followup from the Pelican Staff: Your engine has a timing chain, not a timing belt. I would probably have an expert take a quick look at it if you think something is wrong. - Wayne at Pelican Parts  
SilverRide-o Comments: Hello, 1st great info. quick question though... what is the correct tension or rather, belt deflection? And between which two pulley's do I take the measurement?
August 12, 2010
  Followup from the Pelican Staff: On the E36, the belts use a spring-loaded idler, which is basically self-adjusting, so you don't need to set the tension (unless you have an early 318, at which I recommend about 1/2" or so deflection at the mid-point of the longest length of the belt). - Wayne at Pelican Parts  
Raymond0 Comments: Hi

Recently changed my power steering pump on my 2001 323ci convertable, but since doing that i have had one belt snap almost imediatly after running the car in park for 5 mins, and then on replacing the belt I got less than 15miles out of the car before it has come off the pulley again could there be a fault with the way i put the steering pump in or could it be the wrong pump or is there another fault or something i could have missed that keeps makeing the belt jump off or snap on the pulley, it been the large belt both times??

Thanks for you help and time with this question

Ray Stower, London UK
August 10, 2010
  Followup from the Pelican Staff: That's pretty odd, I would check to make sure the pump is properly aligned with the rest of the other pullies. Also make sure that the new pump is spinning properly - if it's too stiff and not working correctly, it may cause belt problems. - Wayne at Pelican Parts  
Cyril Comments: Hi Wyane
I own a E46 and just want to know what the worst can happen if one drives the car with a defective v belt for a long distance. I would also appreciate if you can clarify the relation between a v belt and an alternator
August 9, 2010
  Followup from the Pelican Staff: The belt takes 10 minutes to change - just change it. The v-belt is what drives the pulley on the alternator. - Wayne at Pelican Parts  
at the end of my belt Comments: I have A BMW 328i 2000.
Just replaced the water pump and had a friend assisting me when taking it apart however I can not remember how the belt ran threw the pullies and have not been able to find a dyogram any were can you show me a diogrm.
June 24, 2010
  Followup from the Pelican Staff: Figure 5 above should be very similar to the belt routing for your car. - Wayne at Pelican Parts  
joez1012 Comments: I went to change my alternator belt the other day in my 93 318i and I couldnt get the tensioner to budge, I made sure to loosen the bolt accordingly but I just couldnt get it to budge, what do you suggest? Thanks a million. Its almost impossible to get any leverage on it.
June 18, 2010
  Followup from the Pelican Staff: There is a bolt that is used to tighten the linkage, and then there is one that turns the toothed sprocket. Make sure that the tightened bolt is loosened first. If you can't get any leverage on it, then you probably need some swivel sockets and extensions so that you can get the angle that you need. - Wayne at Pelican Parts  
laz Comments: what is the easiest way to remove the black plastic cover from over the radiator to change the drive belts?
June 12, 2010
  Followup from the Pelican Staff: Please see our tech article on the radiator replacement (also water pump replacement) for details on removing the shroud. - Wayne at Pelican Parts  
undertaker Comments: I need a diagram to re install the serpentine drive belt on my 2002 530i BMW Help!!!!
May 7, 2010
  Followup from the Pelican Staff: It should be almost identical to the one shown here. - Wayne at Pelican Parts  
gmach Comments: will engine start or get damaged if the fan belt is too loose or breaks
May 3, 2010
  Followup from the Pelican Staff: In general yes, but not if you only run the car for very short periods (a minute or two). The fan belt powers the water pump, which will cause the car to overheat very quickly if it's not operating properly. - Wayne at Pelican Parts  
In4cus Comments: Hi Wayne, just to let you know, I will be purchasing your book, but, in the mean time, I have the mechanical tensioner and it doesn't have an attachment for either a wrench or the XXmm hex socket. What gives? How can I release the tension on it or replace the thing when I need to? I drive a 1997 328i.
March 31, 2010
  Followup from the Pelican Staff: If you remove the dust cap, you can rotate the tensioner using the center bolt, that is if there isn't a hex boss on the tensioner arm. - Nick at Pelican Parts  
In4cus Comments: Hi Wayne, just to let you know, I will be purchasing your book, but, in the mean time, I have the mechanical tensioner and it doesn't have an attachment for either a wrench or the XXmm hex socket. What gives? How can I release the tension on it or replace the thing when I need to?
March 31, 2010
  Followup from the Pelican Staff: Check below the pulley for a hex boss or bolt. Sometimes it canbe hard to located. Is all else fails, you can remove the dust cover and use the bolt on the pulley to compress it. - Nick at Pelican Parts  
Rob H Comments: Just changed the belts on my 94 E34. One of the simplest DIY projects I’ve ever done. Removing the fan and shroud made it much easier.
March 27, 2010
  Followup from the Pelican Staff: Thanks for the feedback. Glad it worked out. - Nick at Pelican Parts  
JOe Comments: We have a BMW 325tds 1997, the water pump packed up, we then decided to replace the a/c belt and the waterpump, power steering pump, alternator belt. All went well with the installation of the belts and water pump, but now there is a weird sound, cannot pin point where it is coming from, but when clutch is pressed in the noise becomes louder, could you advise what this could be????
March 14, 2010
  Followup from the Pelican Staff: Is the noise coming from your engine? If it sounds like it is coming from the drive belt area, remove the belts and inspect each accessory and pulley. Rotate them by hand and listen for noise or a rough bearing. - Nick at Pelican Parts  
Gary Comments: What tool do I need to compress the tensioner to replace it, OR how is this SAFELY performed? The tensioner pulley burned off, and the tensioner is bad. Any assistance on this would be great.
March 8, 2010
  Followup from the Pelican Staff: I use a long handled ratchet with the appropriate sized socket. I don't know what your vehicle is, so it is hard to give specific information. - Nick at Pelican Parts  
Andy Comments: How about the belt routing my 02 745Li ? Is there a good photo or shop view where I can cross referenceto make sure I install mine correctly ?
Thanks,
March 2, 2010
  Followup from the Pelican Staff: Not sure if there is a repair manual out for your vehicle besides buying a subscription to the BMW web site. The cheapest and easiest way to do it is; draw a diagram of the pulleys and belt routing before you remove the belt. - Nick at Pelican Parts  
Drummerboi Comments: I have a 93 325i, and I noticed that my tensioner have the bolt instead of the hex key.Does that mean that I have a mechanical type tensioner? Also, does it work the same as a hydraulic tensioner? Do I just turn the bolt clockwise and it will un-tighten my belt? I am a but confuse about the tensioner that has a bolt and the one that has a hex key. I need some info as I am going to tackle my whole cooling system and belts. Thanks.
February 17, 2010
  Followup from the Pelican Staff: Your engine could have either style of tensioner. Look at the way the betl wraps around the tensioner pulley, then rotate the tensioner away from the belt, toward the are of the pulley with little to no belt wrap. This should release the tension on the belt. - Nick at Pelican Parts  
Dave Comments: on my '96 328i how many belt tensioners are there? I was looking at the photos here on the left and it looks like there are two, but om my can I can only see one up by the Alternator.
December 22, 2009
  Followup from the Pelican Staff: One tensioner is used for the water pump and alternator belt. The other is used for the A/C compressor. A total of two tensioners. - Nick at Pelican Parts  
Kevin Comments: I have an '85 535i E28 with the Sanden ac compressor conversion. Does anyone know what the ac compressor belt size should be for the Sanden unit? The old one broke and it doesn't have any size info on it. I have an old 12.5x 810 and it's way too small. I'm guessing it's at least a 12.5x 850, but want to make sure I get one that will work.

Thanks.
November 7, 2009
  Followup from the Pelican Staff: What I would recommend you do is take the old one down to your local auto parts store and have them match it up against one in stock. Even if they don't have the correct one, you can see the size. Or, simply get a tape measure and measure out the length of the belt - the 850 means 850mm which is 85 centimeters. - Wayne at Pelican Parts  
BlackMansWhip Comments: How would you change the hydraulic tensioner?
November 4, 2009
  Followup from the Pelican Staff: Change the hydraulic belt tensioner? It comes as a complete assembly, you replace it like the spring loaded one. On most cars there are bolts that mount it to the engine. - Wayne at Pelican Parts  
foaxaca Comments: Wayne: I encountered something strange with the driver's side tensioner. Instead of a spot to insert a hex as the A/C belt tensioner had it has a hex bolt. If I start turning the hex bolt, it just starts loosening. The tensioner does not start loosening. I am worried that if I continue loosening, I will just take the tensioner off. That helps me get the belt off but then how do I get it back on so it tightens the belt?
October 21, 2009
  Followup from the Pelican Staff: Put force on the bolt as if you are tightening it, and then it will push against the spring and then you will be able to take the bolt off. If you turn it so that you are loosening it, then you will indeed remove the tensioner - it's designed to be sprung against the spring when tightening it. - Wayne at Pelican Parts  
Robert Comments: is there a technique installing a new belt? even with the tensioner all the way in i cannot slip in the new belt.
October 1, 2009
  Followup from the Pelican Staff: Compare the new belt to the old belt and make sure that it's the correct size. Also make sure that the belt is seated properly in the grooved pulleys before pulling the tensioner. Finally, make sure the tensioner pulley is depressed all the way - these require a large amount of force to move them sometimes. - Wayne at Pelican Parts  
SAS Comments: From everything i read Wayne, the sound seems like it must be my Pulley the small ones Should i replace them both?
September 22, 2009
  Followup from the Pelican Staff: I would replace the main pulley, as this is a common failure. I just replaced this on my 5-Series. Took about 30 minutes and solved my squeaking problem. - Wayne at Pelican Parts  
Candela Comments: You mention in your instructions "The tensioners that hold the belt tight can be easily released using a socket and or XXmm hex tool" What is a XXmm hex tool.
September 20, 2009
  Followup from the Pelican Staff: Ooops, that's a place marker for when I write the books. If I don't know the exact dimension for something, I put in XX and then replace it later on. I'll have to check to see what size this is and then update the article. - Wayne at Pelican Parts  
CDADDY Comments: Please provide information on how to change the belts on a 2002 745i, mines are making a lot of noise and need replacement.

thank you,
September 16, 2009
  Followup from the Pelican Staff: Hi there. I'm pretty sure that on your model car, the belt tensioning system is very similar to the one detailed in this article. - Wayne at Pelican Parts  
Steven Comments: I have both inner belts on my 1991 318is off, but the AC belt has no visible little slidey track to release? How do I release tension on this belt?
September 15, 2009
  Followup from the Pelican Staff: On this car, I believe there is a pulley tensioner. Put a wrench on the tensioner and turn it and it should spring to the side. - Wayne at Pelican Parts  
Jeff Comments: Where is the ABS relay located under the dash in a 1989 BMW 325I. I cannot find one that looks like the replacement, only an orange colored one located behind the ABS CPU. Is this the wrong relay in its place? Thanks for your help.
September 15, 2009
  Followup from the Pelican Staff: There's a metal box under there - that should be your ABS unit. The relay is an aluminum-cased unit, and should be op top of the ABS control unit's housing. You might need a shop lamp to see in there as it can be pretty dark. - Wayne at Pelican Parts  
Grim Reaper Comments: i purchased a belt for my 2000 BMW 741 I and i think it is too big as it has too much slack and i followed the directions shown above. what is the proper length of the fan belt?
July 12, 2009
  Followup from the Pelican Staff: My rule of thumb is to take a look at the belt that is on the car to begin with, before taking it off. It will be marked with a number - that is the length in millimeters of the belt (like 840 means 840mm). Then, make sure that you order the correct sized belt. Particularly on BMWs, different models with different features sold in different parts of the world used varying lengths of belts. - Wayne at Pelican Parts  
smurfless Comments: For those looking at this project on an M3, be advised that the longer engine is a bit harder to get at. I had quite good success from underneath the car, but get a full-face mask to keep the dust and debris out of the eyeballs. But I was able to do both belts from that position without removing anything else. The pictures in the Bentley manual appear to have been taken with the radiator and fan removed, because I couldn't get a hand down from the top.
July 6, 2009
  Followup from the Pelican Staff: The M3 engine is the same exact size as the regular six cylinders. Yes, in some of these photos here too, the radiator has been removed for the purpose of taking very clear photos. - Wayne at Pelican Parts  
panic Comments: I cant tell from the threads I've read but hope I'm not posting in the wrong place. I have a 97 318is. Last December is began squeaking when I started the car, but eventually the squeak stopped. Now the air conditioner wont blow cold air, but the fan still works and there is a load on the engine when I engage the AC from the control panel. So can anyone give me a hint? Do I have one or two belts? Do these symptoms sound familiar? Thanks.
June 19, 2009
  Followup from the Pelican Staff: See the article on checking the fluid / gas within the A/C system - you want to make sure that you don't have a leak. If you have good pressure in there, then there might be a problem with the compressor. - Wayne at Pelican Parts  
Old guys garage Comments: Might want to mention that a 16mm socket is required to move the spring tensioner for the Alt PS belt.
June 11, 2009
  Followup from the Pelican Staff: Thanks for the additonal information. - Nick at Pelican Parts  
BM328i Comments: I will attempt to replace the belts on my 96 328i. I am also going to replace my tensioners. I notice there are 2 types of tensioners available on your website.. 1. Shock Type Hydraulic and 2. Mechanical.. does it matter which one i use?
June 5, 2009
  Followup from the Pelican Staff: The mechanical ones were unavailable for some time, so we were offering the hydraulic ones. I'm not aware of a performance difference between the two - I recently replaced mine on my car and used the mechanical one. - Wayne at Pelican Parts  
golf waterton Comments: Wayne or Terry, do you have a tech article on replacing the tensioner pulley? How do you ship to Canada? I have a very noisy alternator tensioner pulley on my 97 328i convertible.
May 30, 2009
  Followup from the Pelican Staff: I just did this last month on my 5-Series. Three bolts and it comes right off. I had to take off the fan in order to gain access, but I supposed that determined people could do it without removing the fan (although I don't recommend it). We ship to Canada every day - the shopping cart has an International rate calculator. - Wayne at Pelican Parts  
Terry Comments: When replacing the belts, take this opportunity to also replace the the tensioner pulleys. A cheap fix of a big source of engine noise.
May 13, 2009
  Followup from the Pelican Staff: I agree. The tensioners are a wear component. You can quickly remedy noise and have piece of mind knowing they won't fall apart. - Nick at Pelican Parts  
Jim Comments: I need to change out a belt tensioner for a 318i '96 and have not been able to find anything on this fix. It looks like I have to take the alternator out. Any help out there?
May 8, 2009
  Followup from the Pelican Staff: I just replaced the tensioner on my 5-Series last week. Not the same car, but I don't think you need to remove the alternator in order to remove the tensioner. It should be simply bolted to the front of the engine. I did have to remove my fan and housing in order to give me enough room to work in there. Hope this helps. - Wayne at Pelican Parts  
Frank Comments: Does the E36 have 3 or 2 tensioners and an allen wrench can be used instead of the recommended tool?
April 29, 2009
  Followup from the Pelican Staff: There's one tensioner for the main belt, and one for the A/C belt too. Yes, you can theoretically use an Allen wrench to put into the tensioner, but you're going to have to be very strong to turn the tensioner with a small allen wrench. I know that I personally would not be able to do it. - Wayne at Pelican Parts  
jtbimmer Comments: I read this article and attempted to change the belts without removing the fan. I have a 98 328i, and there is no way you can change the belts without taking off the fan. I tried various angles with my tools and the fan shroud and fan were in the way of my wrenches. In the pictures shown it looks possible, but after further review I noticed the fan shroud was missing in the pictures. So if you don't have a fan shroud it might be possible, but if you doand you should or your radiator will not get proper airflowyou will have to remove the fan.
April 23, 2009
  Followup from the Pelican Staff: Indeed, the photos for this article were taken with the fan shroud off, as you cannot see in there with the fan and shroud on. However, I just replaced the belt in my car two weeks ago, and although it was a tight fit, I was able to do it. As it happened, I had to replace a squeaky tensioner right after, so I did end up taking the fan and shroud off the next day. The removal of the fan is easy with the proper tools (see this article: http://www.pelicanparts.com/bmw/techarticles/E36-Radiator-Replacement/E36-Radiator-Replacement.htm for detailed instructions on how to do it.

Indeed, if you want to make life easier on yourself and you have the tools handy, I would spend the additional 5-10 minutes removing the fan. It does make the job a heck of a lot easier. - Wayne at Pelican Parts
 

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