Mercedes-Benz Parts Catalog Mercedes-Benz Accessories Catalog Mercedes-Benz Technical Articles Mercedes-Benz Tech Forums
 
Follow Pelican Parts on Facebook Follow Pelican Parts on Twitter Follow Pelican Parts on Instagram Follow Pelican Parts on YouTube Follow Pelican Parts on Pinterest Follow Pelican Parts on Tumblr
  Search our site:    
View Recent Cars  |   Cart  | Project List | Order Status | Help    
Bookmark and Share

Pelican Technical Article:

Serpentine Belt Replacement

Time:

30 minutes30 mins

Tab:

$60

Talent:

***

Tools:

15mm wrench, screwdrivers

Applicable Models:

Mercedes-Benz E320 (1996-97)

Parts Required:

New belt

Hot Tip:

Check the belt for wear

Performance Gain:

Quieter belts

Complementary Modification:

Replace belt tensioner

One of the routine maintenance items that you should perform on your Mercedes-Benz is the checking and replacement of your serpentine belt. The belt is driven off of the crankshaft and turns the water pump, fan clutch, alternator, and air conditioning compressor. The belt should be checked periodically (every 3,000 miles, or when you change your oil).

The M104 engine uses 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.

When inspecting your belt, the one thing that you want to look for is cracks on the underside of the belt. If you see any cracks at all, you should replace your belt immediately. On the outside of the old belt will be a number that indicates the width and the length of the belt. Use these numbers when ordering a new belt to make sure the replacement is the same as the old one.

Remove the two spring clips that hold the fan shroud in place on the top of the radiator support (green arrows).
Figure 1

Remove the two spring clips that hold the fan shroud in place on the top of the radiator support (green arrows). Pull the coolant line going to the expansion tank out of its groove on the fan shroud (purple arrow) and carefully pull the fan shroud up and out of the engine compartment. This will give you a bit more room to work with. Also remove the black plastic cover on the front of the valve cover (red arrow).

Locate the serpentine belt tensioner to the left of the radiator fan.
Figure 2

Locate the serpentine belt tensioner to the left of the radiator fan. Use a 15mm socket to rotate the tensioner pulley clockwise. This will loosen the serpentine belt and allow you to remove the belt from the alternator pulley. In this picture, you are looking down at the ratchet sitting on the tensioner nut. Now remove the old belt.

Route the new belt (purple arrow) over the various pullies on the engine (green arrows).
Figure 3

Route the new belt (purple arrow) over the various pullies on the engine (green arrows). It helps to route it in such a way that you can quickly rotate the belt tensioner clockwise and slip it up over the tensioner. Once in place, release the tensioner.

In thisPicture, you can see the routing of the belt (purple arrow).
Figure 4

In this picture, you can see the routing of the belt (purple arrow). Note that in this picture, the radiator and most of the front components of the engine have been removed. Also visible is the 15mm bolt in the center of the belt tensioner (green arrow).

Bookmark and Share
Comments and Suggestions:
Dave Comments: I am just trying to get a feel for what is most likely issue and what it entails to repair before I start tearing things apart to inspect. I would not want to open up a can of worms and not be prepared for the full extent of potental problems can of worms

I definitely appreciate the advice. So your earlier suggestion about the balance shaft was just a guess I understand. Of course without tearing it apart and inspecting things nobody could say for sure, I get that.

But based on the description of the sound like it is from the center of the front of the engine between the thermostat housing and the crank from snout, and according to your experience and knowledge of these cars and engines, Your leaning towards balance shaft issues. I think I will expect that I need to tear the whole engine out and replace the entire balance shaft, chains, tensioner, guides gears and whatever else is in there. might as well do it all rather than one piece to find later whole engine needs to removed for the next piece.

Mercedes gets an F grade for poor engineering and design on the repairability of this portion of these w210 cars. I don't know about the other models but I have to say a definitely F grade. I think they might as well have required we pull the engine out to do the spark plugs and change the oil too.

From just doing the water pump, and Mercedes Dealer quoted me 4 hours labor for this E320 wagon with electric cooling fan that is not even getting to the timing chain covers yet. I think just pulling the front covers and oil pan and whatever accessories are in the way to "Inspect" the timing chain and balance shaft components would take at least 8 hours round trip of labor. Thats just to do an inspection.

So now you have the engine front torn apart and you have to decide do I put it back together and then spend another minimum 8 hours more like 16 hours of labor to drop the whole engine later to repair the parts I "Inspected" and found to be faulty? Or do I just drop the engine out now, as it stands with front timing covers removed etc. and then do the repairs? Oh yea, order parts and wait a few days for them to arrive... so the project will likely take a 7-10 days... SIGH!
August 1, 2016
  Followup from the Pelican Staff: I guess it is always worth an inspection first. You h ave to consider the option you'll find it so bad not worth repairing. Worth saving time or maybe finding something less bad when you open it up, (might even be good news once apart). it is a tough spot to be in, but if you like the vehicle it can be worth the repair.

If in doubt of the diagnosis, it is worth getting an opinion from an experienced Benz shop, they will be familiar with the sound of the shaft failing and location of sound. - Nick at Pelican Parts
 
Dave Comments: Could it be a loose timing chain tensioner?
July 16, 2016
  Followup from the Pelican Staff: Could be. Your best bet is to start inspecting items, guessing won't get you anywhere. - Nick at Pelican Parts  
Dave Comments: not sounding good. Is there any tech article regarding this balance shaft / gear problem with e320? some pics and diagrams would help much. In wondering if its possible to just drop the tranny or is that just as much trouble as removing the engine? How many hours labor on average is the repair for such an issue? Do the heads need to be removed also?

Thanks
July 15, 2016
  Followup from the Pelican Staff: It is a full day of work at the minimum. Really depends on your experience.

We don't currently have that tech article. If we get a chance to perform the procedure, we will be sure to document it.

I would grab a repair manual. It will have the procedure, special tools and torque specs.

Give our parts specialists a call at 1-888-280-7799. - Nick at Pelican Parts
 
Dave Comments: OMG, what a horrible piece of German ingenuity and engineering... I guess this was during the time the were owned by Chrysler... very disappointing to hear this.

Does this worn teeth situation often lead to catastrophic failure of engine if not addressed immediately?

thanks
July 14, 2016
  Followup from the Pelican Staff: if that is your issue it could cause the chain to fail. Could cause some damage. - Nick at Pelican Parts  
Dave Comments: yes, I checked with the belt removed. Noise still there. The noise is prominent in the center below the thermostat. i think that is where the balance shaft is located. What typically goes bad on the balance shaft? Can these repairs be done without removing the cylinder heads?
July 13, 2016
  Followup from the Pelican Staff: The engine has to be removed, as there are fasteners at the rear side of the engine, hidden by the bellhousing. The balance shaft teeth and gear wear. - Nick at Pelican Parts  
dave Comments: One thing for sure about Pelican Parts. Great attitude and always respond to questions and posts. That's good service and appreciated. Mercedes being an unusual brand for DIY especially makes Pelican Parts a great resource for the average person.

As for my sisters car. So the 2002 E320 Wagon ended up having an electric main cooling fan and no other auxiliary fans no mechanical clutch fan. It turned out the water pump was old but not the main issue on the E320. Some kind of metallic rattling noise is coming from the front of the engine below thermostat Area between the cylinders.

The noise is between the crank shaft and the thermostat area. Its louder and slower at idle and when warmed up its a bit louder. Noise is faster but smoothes out a little less obvious at higher rpm or while driving above 2000 rpm. Maybe timing chain or pull issues? After an oil change and adding some Lucas Synthetic oil stabilizer it is noticeably quieter at cold start and but as warms up the noise becomes more pronounces. As if the fresh oil kind of better coats the moving parts in there. Engine seems to run ok and has good power and acceleration. No MIL/CELL is on. Any ideas what this problem could be?

Thanks.
July 12, 2016
  Followup from the Pelican Staff: Thanks for the kind words.

Have you removed the belts to confirm the noise is still present? Don't run the engine long, just enough to listen for the noise. If gone, the issue is likely the timing chain or tensioner. Those engines also have balance shaft issues, tear down of the timing chain is required to check it. - Nick at Pelican Parts
 
dave Comments: I did call they were kind and helpful but could not tell me by phone if I had mechanical or electric main fan. Dealer said based on Vin# it was electric. Mercedes seems like a horrible brand of car. The design and support provided to the public is very low quality compared to other major brands like ford or Toyota. This is based on personal experience from owning those types
July 8, 2016
  Followup from the Pelican Staff: Glad you got an answer. Sorry about the benz vibes, I think they would prefer to fix your car for you, rather than you do it. - Nick at Pelican Parts  
DAVE Comments: MY SISTER HAS A 2002 W210 E320 WAGON. I HAVE NOT SEEN UNDER THE HOOD. I AM WONDERING FROM THESE ARTICLES IF HER CAR HAS A CLUTCH FAN OR ELECTRIC FANS. I HAVE SEEN MULTIPLE CONFLICTING REFERENCES ONLINE BUT NOTHING DEFINITIVE. ALSO I CANNOT FIND A SINGLE PHOTO SHOWING THE ENGINE BAY WITH COOLING FANS. THERE WAS MENTION OF A COOLING FAN REPLACEMENT ARTICLE BUT ITS NOT LISTED IN THE PELICANPARTS.COM INDEX. I EVEN GOOGLE SEARCHED THE ENTIRE SITE FOR W210 COOLING FAN AND NO MATCHES FOR THE ARTICLE. PERHAPS HER CAR HAS ELECTRIC AUX FANSPUSHERS IN FRONT OF RADIATOR AND CLUTCH FAN BEHIND PULLER??? I LIVE 200 MILES AWAY AND SHE IS DUMB AS A ROCK WITH CARS SO SHE COULDN'T TELL ME BY PHONE IF SHE HAS A FAN CLUTCH.

I WAS PLANNING TO ORDER A WATER PUMP FOR HER ONLINE, BUT I NOTICED MANY PEOPLE SUGGESTING REPLACING THE FAN CLUTCH AT THE SAME TIME AS THEY USUALLY FAIL AROUND THE SAME AGE. IS THIS TRUE? BUT IF HER CAR IS ELECTRIC FAN COOLED, THEN ITS NOT NEEDED. PLEASE ADVISE.
July 6, 2016
  Followup from the Pelican Staff: You likely have an auxiliary electric fan and mechanical fan.

Give The Pelican Parts parts specialists a call at 1-888-280-7799. They can figure out what part or repair kit you need.
- Nick at Pelican Parts
 
LorenAZ Comments: I really appreciate the people that put this website together.
I wanted to order a serpentine belt for my 96 E320, and according to my owners manual is had the wrong sized belt. Not only that it had the wrong diagram for putting the belt on. With this website I was able to get the correct belt 2225 mm and the correct diagram.
I also change the aux. cooling fan belt. Both tutorials were great and made the repair go very well.
The shop wanted $130 to replace the serpentine belt. I save $100 on that repair, and the aux. cooling belt cost me $8 and I'm sure it would have cost at least $130 at the shop.
Easy repairs, worth the time to do it myself.
My next repair are the flex discs.
Thank you so much for the tech support, advice and parts.
Loren Jennings
March 5, 2016
  Followup from the Pelican Staff: Thanks for the additional info and feedback. We appreciate it.
- Nick at Pelican Parts
 
mksabrawi Comments: very helpful. thanks alot
July 28, 2015
  Followup from the Pelican Staff: No problem. - Nick at Pelican Parts  
Paul Comments: 2005 mercedez benz alternator light on guage disappears and appears ,even the battery is new and charged, when the sign comes out the cars electronics including the transmission do not shift anymore and when i stop the alternator sign disappears and electronics back on again nut when i run again it appears i dont know whats going on with it already i just changed the alternator of this car 4 months ago thats y i was confused if whats going on
May 17, 2015
  Followup from the Pelican Staff: The alternator may be defective. I would check charging system amperage and voltage to confirm this. - Nick at Pelican Parts  
daveB Comments: I need to change the aux drive belt on merc 220 and understand I need a E25 female torx socket which seem unobtainable would welcome any thoughts
March 23, 2015
  Followup from the Pelican Staff: What year and model, engine? This may be a Mercedes-benz specialty tool, if your information is correct. - Nick at Pelican Parts  
emgee Comments: I have a technician put in the serpentine drive belt wrong. This shredded the drive belt in a week.

Same time oil cooler and flap motor went bad as well. Does the wrong installation have anything to do with the flap motor and oil cooler going bad?
March 14, 2015
  Followup from the Pelican Staff: What vehicle are you working on? Did the belt come in contact with the cooler? What flap motor? - Nick at Pelican Parts  
usaims Comments: There is a larger nut next to the pulley, it is kind of hidden - I think you should use that to reduce the tension to remove the belt. It is SO MUCH EASIER!
June 7, 2014
  Followup from the Pelican Staff: Thanks for the additional info and feedback. We appreciate it.
- Nick at Pelican Parts
 
Pete Comments: T was unable to remove the fan cover on my 1993 300E as per your instructsions, The fan prevented removal.Any other instruction on remoing the fan cover? I need to remove the alternator.
April 24, 2014
  Followup from the Pelican Staff: This article applies to:
W210 E320 (1996-97)


You may have to remove your mechanical fan to get your shroud off.
- Nick at Pelican Parts
 
97E320 Comments: Correction: I thought I knew what I was doing and I'm smart enough to ***stop when something is not easy***. Consult this article.
April 6, 2014
  Followup from the Pelican Staff: Thanks for the feedback. Glad we could help.
- Nick at Pelican Parts
 
97E320 Comments: I used a couple articles from you now. I will buy some parts now. Thank you! My Story: I was trying to turn the tensioner counterclockwise.

I thought I knew what I was doing and I'm smart enough to stop when something is easy.

Critical points:
0. Turn the tensioner ***Clockwise*** to release. About 60 ft lbs of torque to move it in my estimation. It should move freely.
1. Make a drawing first
2. Have a bright flashlight
3. Have this article ready.
4. measure the old belt against the new one, they should seem similar with the new one being potentially slightly smaller. If you have the wrong belt, you will know it. I fyou ahve that thought like, "um... that's odd", you probably have the wrong belt. Have a second car ready.

I have found that I got the belt on more easily by doing all but the tensioner at first, however to get the tensioner socket on you can't stretch a new belt that far. So... At that point, remove the far left end, alternator see picture 4 of write up. Then when you roll on the tensioner all the way to the stops, you can slip the belt over the alternor and it's guide above and right 1 position. It's not super easy and you kind of have to massage it over the ribs of the alternator, but it was WAY easier than any other options I could see, considering you have to have a wrench on the tensioner to do this.

Also, I pushed the socket wrench with my right hand, knuckles near the radiator. Left hand to set the belt and remove it from the alternator. Guess what? One little bump and 4 razor slices in my right hand knuckle. Mechanics gloves might be a good idea, especially with a car like mine. Her name is LaFawnDuh, she's a little bitchy, and bites. :- See picture, attached.

I checked all pulleys with a fresh LED maglight. My 10 year old daughter then repeated with her hands to feel that they were all seated and get a little dirty.

1/2 Turn over, do not start. Check the whole belt again.

Test start. Should be really quiet compared to before, nearly no noise is good.

Stop. Check the whole belt again for abnormal wear, lines, damage, check each pulley with a bright flashlight.

Test drive and enjoy the $120 in labor you just saved. Consider doing your own brakes now. There's another good article on this site and it's super easy, as with most maintenance jobs on Mercedes. Mercedes are super well engineered for maintenance.
April 6, 2014
  Followup from the Pelican Staff: Thanks for the additional info and feedback. Glad we could help.
- Nick at Pelican Parts
 
carlos Comments: HELP. 1997 and 1998 with A/C.

1- Are the 1997 and 1998 serpentine routing the same.
2- Are the belt tensioners the same for both years?
3- Is the serpentine belt the same for both years?
March 31, 2014
  Followup from the Pelican Staff: This article does not apply to 1998 models. - Nick at Pelican Parts  
97-320 Comments: your advice needed on changeng 97\320 bayrings
March 28, 2014
  Followup from the Pelican Staff: I don't understand the question - Nick at Pelican Parts  
Steven Comments: Jemmy I'd love to see what you did!
March 27, 2014
  Followup from the Pelican Staff: Hopefully Jemmy will share the tool. - Nick at Pelican Parts  
shad Comments: Im
Hearing voices from my engine. And we isolated the problem as being the air conditioner compressor pully. But it need time to order and i need to use my car. So i was wondering if there is a way or lets say a special configeration that allows me to run my engine but isolate the pully of the ac. Maybe using a shorter belt. Of course temporarely for the new parts to b available. If anyone could help plz
March 15, 2014
  Followup from the Pelican Staff: If your model was available without A/C, you can install that belt. You may have to install a pulley to bypass it. Give our parts specialists a call at 1-888-280-7799. They can help you find the right part.
- Nick at Pelican Parts
 
Rev Ron Comments: I got huge problem with my 2006 Ford f150 5.4 triton engine. Engine light came on saying 7 and 8 injector bad. I replaced and now its running even worse. Help
March 2, 2014
  Followup from the Pelican Staff: I would check that the injector wiring is not shorted or faulty. You may also have an issue with a different engine component causing the rough running. - Nick at Pelican Parts  
rev ron Comments: First Mercedes I have ever worked on. Pelican was a great help in my changing of serpentine belt. Would help if you had a diagram of belt pattern.
March 1, 2014
  Followup from the Pelican Staff: We do not have a diagram for the belt.

Thanks for the feedback. Glad we could help.
- Nick at Pelican Parts
 
Wenzel1220 Comments: Is there a diy guide for a 97 E 420 serpentine belt swap? Also what else should I check while doing this?

Thank you
March 1, 2014
  Followup from the Pelican Staff: We don't currently have that tech article. If we get the chance to perform the repair, we will be sure to document the process.

Applicable Models:
W210 E320 (1996-97) - Nick at Pelican Parts
 
71LS5 Comments: When replacing the belt on a '97 E320, should I also replace the tensioner and pulley and the idler pulley?
November 4, 2013
  Followup from the Pelican Staff: I would inspect them and see if the bearings feel smooth and are quiet. If there is any doubt, replace them - Nick at Pelican Parts  
Rowdy Comments: Do you have a photograph of a 1991 300sl serpentine belt and belt tensioner and how to replace?
September 30, 2013
  Followup from the Pelican Staff: Look in our tech forums and the procedure and digram are both in there. You need to follow the routing for the 104 engine - Kerry at Pelican Parts  
Dave Comments: I have a 86 MB 300E, I am trying to replace the serpentine belt but the one shows will fit this vehicle, seems not to fit. Any comments or suggestions??? Thank you
September 2, 2013
  Followup from the Pelican Staff: This tech article does not apply to your vehicle. I attached a diagram that should be similar to your vehicle.
Give our parts specialists a call at 1-888-280-7799. They can help you find the right belt.- Nick at Pelican Parts
alex Comments: hi i have a 1998 Mercedes-Benz CLK320 Coupe and need to replace both fan belts but i dont have a diagram of which belt goes where theres two belts 1 small 1 large if i could get a diagram of one with the small belt on and one with larger belt on i would be appreciated thanks in advance Alex from Australia
August 5, 2013
  Followup from the Pelican Staff: Can you use the photo from diagram 4 to help with the belt routing. - Kerry at Pelican Parts  
bg Comments: What causes this belt to break. It was a new belt
July 1, 2013
  Followup from the Pelican Staff: Without personally inspecting the vehicle, all I can do is guess..

IMO: There is "NO" common serpentine belt design flaw on this engine, you "MUST" inspect all possible causes every time.

A damaged:
* Belt tensioner or pulley
* Idler pulley
* Water pump
* Alternator
* Power steering pump
* A/C compressor

Other possible causes:
* Incorrect belt installed
* Defective belt
* Incorrect belt routing
* Damaged or defective harmonic balancer
* Bad engine mount
* Vehicle modification
* Road debris
* Broken timing cover
* Sabotage

-whunter-
 
Chris Comments: Replaced serpentine belt on 1999 c280 Mercedes Benz and it shredded again within 2 days of repair. There is a fluid leaking could it be power steering fluid ? Any suggestions what could be causing belt to shredd.
June 25, 2013
  Followup from the Pelican Staff: Sorry, this requires LOCAL hands on diagnosis, before the engine is damaged.
-whunter-
 
Jemmy Comments: On my car it is a 19mm bolt,and it is hellisly tight! I have a 190E 1.8 1993 Merc manual,and I snapped off the 13mm tensioning bolt,as it had seized,so had to make up a new tensioning device, which works well.If anyone wants some advice,please mail me.
May 20, 2013
  Followup from the Pelican Staff: Usually the excess tension is caused by corrosion, glad you resolved the issue.
- whunter
 
samrethy sok Comments: question, How can i get the 15 mm torx socket?
April 25, 2013
  Followup from the Pelican Staff: If you must have it today, most retail tool and car part stores carry this.

We have it in many sets.
http://www.pelicanparts.com/Mercedes-Benz/catalog/ShopCart/TOOL/POR_TOOL_WTD166-detail.htm

roy@pelicanparts.com
 
skinny Comments: how about a "sticky" on year2000 e320 with ONE drive fan electric in back of radiator
September 5, 2012
  Followup from the Pelican Staff: I will see what can be done.

- whunter
 

  Search our site:    

View Cart & CheckOut | Project List | Order Status |  Help    

 

[Home] [Customer Service] [Shopping Cart] [Project/Wish List]
  [Privacy Statement]  [Contact Us] [About Us] [Shipping] [Careers]

Copyright © Pelican Parts Inc. -    DMCA Registered Agent Contact Page

Page last updated: Wed 9/28/2016 02:12:28 AM