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Pelican Technical Article:

Fixing Common Vacuum Leaks

Time:

3 hours3 hrs

Tab:

$10 to $300

Talent:

***

Tools:

All of them

Applicable Models:

Mercedes-Benz W210 (1996-03)

Parts Required:

New gaskets, seals

Hot Tip:

Take your time and clean everything well.

This article specifically covers the W210 Mercedes with the M104 engine, however the concepts I'll go over apply to nearly all fuel-injected gasoline engines. In a gasoline engine, the speed of the engine is controlled by the amount of air that enters through the throttle body. In a diesel engine, there is no throttle body. The speed of the engine is controlled by the amount of fuel injected into the cylinders. Diesel engines are a different animal that we will cover in a different article.

A poorly running car can often run amazingly well after an afternoon's worth of work, going through the various rubber boots and hoses around the engine. Vacuum lines, intake boots, seals and many other small gaskets around the engine can be the source of poor running and idle problems.

Many times, a lean running condition can be traced back to a cracked or torn boot in the system. A good quick way to check the overall health of the system is to take the oil filler cap off with the engine running. If the system is in good shape, the idle of the engine should drop and the car will run rougher. This is due to the extra unmetered air flowing through the oil filler port. If there is no change in the vehicle's idle, then you probably have a vacuum leak somewhere in the system.

Don't forget to check places where vacuum leaks may not be as obvious, such as the oil filler cap, the dipstick and also the valve cover. The cover itself has 23 different seals on it! Each fastening bolt of the cover uses a sealing grommet underneath it. These are especially susceptible to cracking as they age. Replacement is pretty straightforward: just loosen each 10mm bolt, then pry the old sealing ring out of the valve cover and replace it with a new one. Around the perimeter of the valve cover, you'll want to replace the cover gasket as well as the 6 grommets that get sandwiched between the cylinder head and the valve cover. Both the valve cover gasket and spark plug grommets need to be glued into place. This is most easily done by using a few dabs of gasket adhesive every couple of inches in the channels around the perimeter of the valve cover and also the spark plug holes.

     Valve Cover

One problem with the M104 is that corrosion develops under the coating on both the inside and outside of the valve cover. The coating on the valve cover is something similar to powder coating. I've been told that this coating was added to aid in sound deadening on the top of the engine. I haven't been able to find any information confirming this, but it seems consistent with the engineering of the car.

The corrosion of the valve cover typically begins under the coating and begins to eat away at the magnesium. This results in patches of flaking, powdery metal coming off. It can also result in a warped sealing edge along the bottom of the cover. This causes both a vacuum leak and an oil leak. This occurred on our project car. In our case, the valve cover had corroded so badly that trying to remove the coating over the metal caused even worse damage to the valve cover. One other thing that can happen is that as the inside corrodes, chunks of the coating and valve cover can fall right into the engine, potentially causing damage to the camshafts and valvetrain, or even worse, it might fall into the oil sump and clog up the oil pump strainer. If this happens, you can starve the engine of oil and seriously damage the engine to the point where a rebuild is required.

I haven't been able to confirm it, but I have been told by a few different sources that some later versions of the M104 came with an aluminum valve cover in an attempt to solve the problem. A new valve cover costs around $600 and is only available through Mercedes-Benz. Even then, I can't confirm if the new valve cover is aluminum or magnesium. In our case, we managed to find a magnesium valve cover, still in good shape from a local Mercedes dismantler. This gave us a bit more piece of mind putting everything back together.

     Idle Fluctuation

For the most part, the speed of an engine with fuel injection is regulated at idle by a small electrically operated valve. This allows air to bypass the throttle body, keeping the engine running. This valve can be called a few different things such as an Auxiliary Air Valve, Idle Regulator or Idle Control Valve. For the purposes of this article, we will refer to it as an Idle Control Valve, or ICV.

The ICV is controlled by various sensors on the engine that monitor different parameters. Over time, as a car ages, heat and the elements can cause the various seals and boots around the engine to crack allowing extra air to enter the engine. This air is called "unmetered" air. This means that the car's fuel injection system cannot recognize the increased airflow. The typical failure mode in this instance is a surging idle usually going from 1200RPM to 2500RPM, back and forth. This is the number one tell-tale sign of a vacuum leak downstream of the ICV. What is happening here is that the fuel injection computer is caught in a feedback loop. Typically, this will not damage anything in the fuel injection system if caught right away. Just be sure to check all possible places air can leak in between the cylinders and the ICV. This also includes the oil dipstick O-ring, the oil filler cap, valve cover gasket, PCV valve and also the intake manifold gaskets.

Sometimes, the process of eliminating all of the leaks can be quite frustrating. Just when you think you have sorted out all of the potentially leaking seals, you find that the idle still fluctuates. Just take your time and methodically check all of the seals in the system.

     PCV Valve

The PCV valve or positive crankcase ventilation valve is used to re-direct gases from the crankcase back into the intake of the engine. As the crankshaft spins inside the engine, it generates pressure waves of air, oil mist and other combustion gases inside. If these gases were not vented out of the crankcase, it would build up pressure inside the engine. Given enough pressure, it could start to blow out seals in the engine. Additionally, the engine would have to work harder to overcome the extra force of the pressure. The PCV valve is a one way valve that allows the gases to flow out of the crankcase but not back in. In the old days, the PCV would just vent to the outside atmosphere through a breather, usually on top of the valve cover.

Nowadays, with more stringent environmental laws, these gases are re-directed back into the intake of the car. The engine vacuum also helps to suck these gases out of the crankcase. Usually, the PCV gets stuck open, allowing oil mist, air and other combustion gases to travel back into the crankcase. This can sometimes cause a condition called blow-by, in which all the muck gets stuck in the PCV lines, eventually clogging it. Typically, you can remove the PCV valve and blow through it to check its operation. If you can blow through it in both directions, the valve is stuck open. Try squirting a few shots of brake cleaner through the valve to clean it up inside. More often than not, you can simply free up the valve and return it to normal operation. I've rarely come across a valve that can't be cleaned up.

     Brake Booster

Various components on the car are actuated by engine vacuum. The biggest one is the power brakes. This system uses a large diaphragm mounted on the end of the brake master cylinder. The idea is to use engine vacuum to amplify the strength of the brakes when you push down on the pedal. Typically, if a brake booster fails, it will become very difficult to operate the brakes. This will feel like you have to push down the pedal much harder to get the car to slow down. An easy way to test if the brake booster system is working properly is to put your foot on the brake pedal with the engine turned off. Once you start the engine, you should feel the brake pedal sink down a little. If you don't feel the pedal sink down, something is probably wrong with the system.

The first thing to check is the small one way valve mounted in the vacuum line going to the booster. Usually this is mounted right at the booster. Take it out and try to blow through the valve both ways. If you can blow air through both sides, the valve is shot and must be replaced. If not, the booster is probably suspect. You may also want to inspect the grommet that secures the vacuum line to the brake booster for cracks.

If the one way valve, grommet and line are ok, then the booster likely has a torn diaphragm and must be replaced. Brake boosters are one of those items that are usually expensive; however, it's somewhat rare for them to fail.

     A Labyrinth of Vacuum

All around the engine are smaller vacuum lines that are used to actuate smaller valves, solenoids and also the fuel pressure regulator. Mercedes uses a combination of plastic vacuum line and rubber connectors to route vacuum throughout the engine bay. The rubber ends of these connectors break down over the years and eventually allow air to enter the system.

On the right (passenger) side of the engine, you have one vacuum line that runs from the exhaust gas re-circulation valve to the actuator solenoid on the front of the engine. Most of this line sits underneath the ignition coil cover. On the left (drivers) side of the engine, there is a vacuum connection that comes off the intake manifold and goes to the fuel pressure regulator.

Up until the early 2000's Mercedes Benz used a vacuum system to operate the central locking system for the doors, trunk and gas flap of the car. While somewhat antiquated by today's standards, the system was novel for its day. When central locking first appeared on cars, the electrical components were large, noisy and not as reliable as they are today. A vacuum-operated system has the benefit of silence, reduced complexity and the ability to troubleshoot the system with relative ease if something goes wrong. A diagram of the vacuum system on these cars may appear to be somewhat complicated; however the system is actually quite simple when you understand the basic theory.

An often overlooked vacuum seal is the small O-ring on the dipstick as shown here.
Figure 1

An often overlooked vacuum seal is the small O-ring on the dipstick as shown here.

Check the curved rubber fittings on the ends of the vacuum lines for cracks.
Figure 2

Check the curved rubber fittings on the ends of the vacuum lines for cracks. If they are cracked, replace them.

You may also want to check the oil filler cap seal as air can leak from this seal as well.
Figure 3

You may also want to check the oil filler cap seal as air can leak from this seal as well.

Squeeze the two tabs (green arrows) on the electrical connector together to release it from the MAF sensor.
Figure 4

Squeeze the two tabs (green arrows) on the electrical connector together to release it from the MAF sensor.

Release the two clips on the top and bottom of the MAF sensor housing (green arrows).
Figure 5

Release the two clips on the top and bottom of the MAF sensor housing (green arrows). Pull the end of the MAF sensor housing out of the airbox housing.

Loosen the hose clamp on the other end of the MAF sensor housing to release it from the intake hose (green arrow).
Figure 6

Loosen the hose clamp on the other end of the MAF sensor housing to release it from the intake hose (green arrow). Pull the MAF sensor housing out of the intake hose. At this point, check the ends of the intake hose for any cracking. If the boot is cracked, replace it.

Now remove the three 10mm bolts holding the upper intake hose to the valve cover (green arrows).
Figure 7

Now remove the three 10mm bolts holding the upper intake hose to the valve cover (green arrows).

You'll also need to loosen the hose clamp holding the upper intake plenum to the throttle body.
Figure 8

You'll also need to loosen the hose clamp holding the upper intake plenum to the throttle body. The clamp itself is located in a tight space. A set of universal joint sockets as shown here makes this job much easier. Once the hose clamp is loose, pull the whole intake plenum assembly up and off the valve cover.

Now remove the 5mm hex bolts securing the valve cover insert piece to the valve cover (green arrows).
Figure 9

Now remove the 5mm hex bolts securing the valve cover insert piece to the valve cover (green arrows). Also take note of the firing order of the engine embossed into the insert piece (red arrow). This diagram is helpful if you forget where each sparkplug lead goes on the car.

Once the insert piece is removed, you'll see the ignition coils and wires underneath.
Figure 10

Once the insert piece is removed, you'll see the ignition coils and wires underneath. You'll want to remove the front cover off the front of the valve cover (red arrow) and also the cover over the fuel injectors (yellow arrow). Also remove the vacuum line connection from the exhaust valve (purple arrow). This connection runs forward to a solenoid at the front of the cylinder head. Also remove the spacer piece that covers the ignition coil wiring (green arrow).

In this picture you see the branched ignition connector coming from the coil.
Figure 11

In this picture you see the branched ignition connector coming from the coil. Pull it up to release it from the spark plug.

In this picture we see the coil itself on top of one of the spark plugs.
Figure 12

In this picture we see the coil itself on top of one of the spark plugs. Simply pull it up to lift it up and off the spark plug.

Remove all of the 10mm bolts that hold the valve cover to the cylinder head.
Figure 13

Remove all of the 10mm bolts that hold the valve cover to the cylinder head. In this picture, all of the bolts have already been removed. Once all the bolts are removed, gently pry the valve cover up and off the engine. If it seems stuck on there, give it a few knocks with a rubber mallet to free it up. Once off, remove the old gaskets from the valve cover.

Here is the engine with the valve cover removed.
Figure 14

Here is the engine with the valve cover removed. Be sure to remove the two old cam plug gaskets on the very end of the cylinder head (green arrows).

Now turn the valve cover over and remove the small Phillips head screws that hold the baffle plates to the inside of the valve covers (green arrows).
Figure 15

Now turn the valve cover over and remove the small Phillips head screws that hold the baffle plates to the inside of the valve covers (green arrows). Once removed, you will be able to access the top grommets on the valve cover.

Drive out the valve cover grommets using a large socket or drift.
Figure 16

Drive out the valve cover grommets using a large socket or drift. Shown here is one of the new grommets that fit into the top of the valve cover. You'll want to tap it into place using a rubber mallet.

Here is the valve cover with the new gaskets installed.
Figure 17

Here is the valve cover with the new gaskets installed. You may need to use a bit of gasket adhesive to hold the gaskets in place while fitting it to the cylinder head.

Don't forget to replace the two end plugs towards the rear of the cylinder head (green arrows).
Figure 18

Don't forget to replace the two end plugs towards the rear of the cylinder head (green arrows).

Now place the valve cover back on the cylinder head.
Figure 19

Now place the valve cover back on the cylinder head. Make sure that all of the gaskets are seated correctly.

Shown here is a new grommet for the valve cover retaining bolts installed in the valve cover (green arrow).
Figure 20

Shown here is a new grommet for the valve cover retaining bolts installed in the valve cover (green arrow).

Tighten all of the valve cover bolts to 14ft.
Figure 21

Tighten all of the valve cover bolts to 14ft./lbs. in a criss-cross pattern.

Shown here is a new vacuum end connector for the Mercedes M104 engine.
Figure 22

Shown here is a new vacuum end connector for the Mercedes M104 engine. You'll find a variety of these around the engine. Replace them as needed.

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Comments and Suggestions:
t-ham Comments: Hi Nick, I have a 1996 C220 with the same issue as deesellers with idle moving between 600-1000rpm. The car also stalls right after starting if the engine is hot. Could this also be caused by the vacuum leak? Thanks
November 16, 2016
  Followup from the Pelican Staff: Yes, it could be or a faulty idle control system. - Nick at Pelican Parts  
ozzyo4 Comments: have1998 c230 kompresser idels perfect wantsto stall wen give it gas . can get it throttle op if I keep pumping gas pedal ,have no air leaks to be found in intake duct system .any ideas
September 25, 2016
  Followup from the Pelican Staff: Is the check engine light on or flashing when the problem is present? Sounds like an engine misfire. I would check spark, fuel and compression on all cylinders.
- Nick at Pelican Parts
 
Ken Comments: Seeking assistance on correct connection for Vacuum cross over valve for 93 300 CE Cab.
Valve has six vacuum connectors and four electrical hookups
Ouch!
September 21, 2016
  Followup from the Pelican Staff: I don't have that info.

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 wiring.
Give our parts specialists a call at 1-888-280-7799. - Nick at Pelican Parts
 
Dick Comments: 03 Mercedes clk430 v8 . When I start car cold it's okay. When it's warm it won't start unless I floor gas pedal then it takes about 45 seconds with pedal still Flores to be able to idle. Checked vacuum it's 18 inches.
The engine codes are PO 171 & PO174 lean both 1 & 2 banks.
Help, Richard
September 20, 2016
  Followup from the Pelican Staff: I can't help without knowing what is missing from the system when you are trying to start it. When your engine doesn’t start you’ll want to check the basics. Check spark, fuel injector pulse and fuel pressure, volume, quality and engine compression. Are there any fault codes? Once you figure out what is missing, it will be easier to diagnose.
- Nick at Pelican Parts
 
Comments: To start with, I am very impressed with the above article largely related to vacuum leaks with my 1993 300CE, Cab.
It appears I have a problem with my Switch Over Valve which has six vacuum lines that has become disconnected.
Today I spoke with a very helpful person at P.P. but he made it clear P.P. does not provide Tech Support.
My objective is to purchase a Switch Over Valve if necessary. Or, more importantly locate someone to assist in the proper assignment of the six lines to the proper location, on the valve, itself... if possible????

Thank you very much:
September 6, 2016
  Followup from the Pelican Staff: If you have the valve in hand, you can mark and label the old valve line locations. Then install the new one using your notes. - Nick at Pelican Parts  
Bekiva Comments: Hi, thanks for your effort to help us. I have a 94 E320, it runs great, but when the engine is warmwd up, and runs on idle, it stops when I push the throttle pedal. I can avoid it if I push the pedal very slovly. But that its difficult while driving in tovns etc. Any idea whats wrong?
September 3, 2016
  Followup from the Pelican Staff: You could have an air leak or faulty mass air flow sensor. - Nick at Pelican Parts  
deesellers Comments: Hi everyone,i have 1996 C220 2.2L gas the idle fluctuates between 800 and 1000 rpm after warm up,i checked for vacuum leak didn't find any,i did notice when i remove oil filler cap it blows air,i am not sure if its normal,i bought the car used.I would appreciate any help i can get,also like to know where the PCV valve is located,thanks.
August 5, 2016
  Followup from the Pelican Staff: The crankcase does produce pressure, air escaping or entering the valve cover with the cap removed is normal. You likely have a vacuum leak you can't find or an issue with the idle control circuit. - Nick at Pelican Parts  
Rallen Comments: I see that you say a diesel is a different animal and I most definitely agree. Have you written about the w210 diesel and its problems with vacuum leaks and any other tid bid that can help me since the diesel does not have a throttle?
August 1, 2016
  Followup from the Pelican Staff: We have not added info on the diesel yet. We don;t have that engine in the US, but most times they have a flap but not a throttle housing.

- Nick at Pelican Parts
 
Zorro Comments: Hy i have a 1991 190e 2.3 and a 1994 300e twin cam motor, can i swap the 300e motor to the 190e and do i have to change harnnes.
July 15, 2016
  Followup from the Pelican Staff: I believe you would need the harness and DME. - Nick at Pelican Parts  
dana B Comments: 01 e320 wagon where does vacuume hose on left side rear of intake go? i replaced valvecover gaskets , and now cant find location for this vacuume hose..... any ideas??
May 21, 2016
  Followup from the Pelican Staff: Try this. - Nick at Pelican Parts
SANDY Comments: ANY IDEA WHERE I CAN GET A TROUBLE SHOOTING/REPAIR MANUAL FOR A 1998 MERCEDES E320? I LIKE TO DO MY OWN REPAIRS AND HAVE NEVER OWNED A MERCEDES BEFORE, A REAL BOOK WOULD MAKE THINGS SIMPLER. THANKS
May 4, 2016
  Followup from the Pelican Staff: Give our parts specialists a call at 1-888-280-7799. They can help you find it. If not, it may have to come from Mercedes-benz.
- Nick at Pelican Parts
 
The Augerer Comments: I own a 2004 C240 4Matic and for the past couple of months it would, after a long trip, begin to idle rough at a stoplight. When in park the engine would rev up to 2000 RPM. When going home one day the car wouldn't maintain any consistent RPM and attempted to stall several times. After that it will start and rev to 2000 RPM, drop to 1000 for a second, then stall. The problem continues even with a new MAF.
April 14, 2016
  Followup from the Pelican Staff: Sounds like a misfire or a vacuum leak. I would start by looking for a vacuum leak. - Nick at Pelican Parts  
Subz123 Comments: All four spark when tested out of block..but when placed back in and take them out the 3rd spark plug is soaked in petrol...when vacuum pipe pulled off inlet manifold engine ideals normal but can still hear engine missfire under 3000 revs on stand still in gear car Judders and there is loss of power.
March 25, 2016
  Followup from the Pelican Staff: You may have a fuel injector stuck open. Check fuel pressure, does it hold once it pumps up and the engine is off? - Nick at Pelican Parts  
Subz123 Comments: I have replaced spark plugs and fuel injectors engine block valve
March 25, 2016
  Followup from the Pelican Staff: Replacing items doesn't confirm the function. - Nick at Pelican Parts  
Subz123 Comments: Hi plz help I have a Mercedes a class 140 automatic. When plugged in my computer its coming up cylinder 3 misfire and it ideal is fluttering low I've replaced my spark plugs,coil pack,injector's, engine block valve but when I take breather pipes off it seems to stop my cylinder 3 missfire and says random misfire I'm assuming its some sourt of air leak but haven't a clue were to start any ideas would be much appreciated
March 24, 2016
  Followup from the Pelican Staff: If it was an air leak, it would likely cause a misfire on all cylinders. I would check spark, fuel and compression on all cylinders. - Nick at Pelican Parts  
Steve's fine thank yoy Comments: I have just purchased my first used Mercedes now I'm getting it running smooth so I started looking online for help and I came across your little talk group there I very much appreciated finding it and spent most time necessary read every single thing comments that were made about and I walked away feeling more informed and comfortable about my decision and what I need to do so this is just a thank you for not only having the service but actually getting on there in responding
March 14, 2016
  Followup from the Pelican Staff: We are here to help. - Nick at Pelican Parts  
Rckinrob Comments: Hey rick ..u might want to check a spring near the throttle control mine broke and was doing what yours is.it pulls down this lever to keep idle down...maybe this helps
March 13, 2016
  Followup from the Pelican Staff: Thanks for the input on this one. We appreciate the help.
- Nick at Pelican Parts
 
Rckinrob Comments: 95 c220 check engine light on..code is saying low pressure in air injector..any help?
March 13, 2016
  Followup from the Pelican Staff: Could be a secondary air code? Maybe the pump or check valve is faulty. - Nick at Pelican Parts  
rick Comments: In response to 3.02 response... the codes stored are p 0441 , p 0505, p1444 .. mercedes c280 1995... apparently MAF ok..
March 3, 2016
  Followup from the Pelican Staff: How do you know the MAF is OK? What is GPS at idle, 2500 rpm and steady cruise? What is calculated load during the same operating states?

The fault codes point to a problem with the evap system and idle control issue. The DME sees the issue with the idle. Check if the purge solenoid is stuck open.- Nick at Pelican Parts
 
rick Comments: I have a 95 c280 ... 1st throttle body ruined.. 2nd throttle body diagnosed and its ok.. changed idle air resonance valve.. still running between 1500 to 1600 rpm when idle...
March 2, 2016
  Followup from the Pelican Staff: Sounds like you have either a vacuum leak or a faulty MAF sensor. Are any fault codes stored? - Nick at Pelican Parts  
ajax Comments: After a closer look, I guess my car, '96 s320, does have the electric air pump. I will check the elec connector on that tomorrow. Is there an easy way to check the pump operation?
March 1, 2016
  Followup from the Pelican Staff: When you start the vehicle, check the pump connector for power and ground. - Nick at Pelican Parts  
ajax Comments: I have '96 s320 that keeps getting a CEL with code P0400, intermitantly, as in sometimes within 10 miles, sometimes after 100 miles. So far I have replaced the control solenoid at the front of the engine, replaced much of the plastic vac hose with rubber, checked the small check valve at the vac source on the intake, cleaned the egr valve and op checked with a mity vac, cleaned the air pump check valve, it was crudy and could probably use more cleaing, and op check with mity vac. Also confirmed lines are not plugged from exh manifold and the line to the intake manifold. Engine runs fine with CEL on or off, only a slight rpm flux in gear at a stop, hardly enough to notice. should the engine driven air pump be delivering air to the check valve all the time with the engine idling?
March 1, 2016
  Followup from the Pelican Staff: Air is created from mechanical pumps all the time, solenoids direct the air when needed. - Nick at Pelican Parts  
Mdu Comments: I have replaced the breather pipe and sorted out the brakes and refuel the gear box with Transmission oil but the jittering is still there when it changed from gear to gear.
February 29, 2016
  Followup from the Pelican Staff: This could be a pressure issue in the trans or an engine misfire. Check if the pressure looks normal using a Mercedes-Benz scan tool. - Nick at Pelican Parts  
Hammer Comments: I have a 1999 SL500 engine check light is on code reads fuel pressure leak. The fuel tank is normally pressurized. When the fuel cap is removed you can hear a sucking noise which is not present. I have replaced the fuel cap and the fuel filter. The light is still on. There are no obvious fuel leaks. I would like to find out if you know what the possible cause is.
February 27, 2016
  Followup from the Pelican Staff: There could be a faulty evap line or hose to the fuel tank, or a faulty electronic solenoid. I would suggest smoke testing the system. - Nick at Pelican Parts  
Hammer Comments: I have a 1999 SL500 The fuel tank is not pressurizing. I have replaced the fuel cap.The engine check light is on.
What are the possible fixes?
February 26, 2016
  Followup from the Pelican Staff: Pressurizing how? Please explain what you are trying to fix. - Nick at Pelican Parts  
Mdu Comments: I have a C240 2001 merc, I want to clean the engine any suggestion on how and what must I use and must I keep the engine running or not?
February 24, 2016
  Followup from the Pelican Staff: Use a spray cleaner and rags to wipe it down, when the engine off off and cool. I would avoid getting it wet or working on it when running. - Nick at Pelican Parts  
Mdu Comments: I have a C240 2001 merc, it started jittering and then gear selection is poor, I then noticed that the breather air-intake pipe was broken, and my brakes are not working well I hear a hissing noise from the break booster.
February 24, 2016
  Followup from the Pelican Staff: Sounds like a major vacuum leak. I would repair the broken hose. - Nick at Pelican Parts  
Cobi Comments: I have a 1999 e320 I notice my check engine light came on then I notice the old cap off the I put it on and notice I had a oil leak under the car then I checked the dip stick and it was over field with oil and I smell burn old when driving
February 22, 2016
  Followup from the Pelican Staff: What are the fault codes that are stored? - Nick at Pelican Parts  
420 SEL Crazy Comments: When the engine warms up - the transmission shifts are hard.
When the engine is cold - the shifting is smooth.
What could cause this
My car is a 1989 420 SEL
February 18, 2016
  Followup from the Pelican Staff: The trans may be overheating. I would check if the cooler is blocked or faulty. - Nick at Pelican Parts  
Robby Comments: Hello.. I have a 1994 E220 with an M111.960 engine. It just went over 300,000km a couple of months ago. Engine rpm is fine and smooth when car is driving. But if at traffic light waiting for green or stopped for length of time with AT in gear, the rpm would drop from 700-800 to 300-400rpm every 30-40 seconds and the entire car would shudder and shake. Is this the start of the throttle body going bad?

Thank you in advance.
February 12, 2016
  Followup from the Pelican Staff: Sounds like an engine misfire. I would check spark, fuel and compression on all cylinders. - Nick at Pelican Parts  
baby Comments: I have a 1992 mercedes benz 400SE that had fuel injecters vacuum leak and i put new o rings on all of them, now it leaking vacuum some where and i cant find where. can you help me Eulace
January 8, 2016
  Followup from the Pelican Staff: Try a smoke test machine with the engine cold. The leak should show up. - Nick at Pelican Parts  
Yawar Comments: I have bmw 740 li, 2007. The engine misses when hot. It generates low roaring sound and slight vibrations also when I put it in drive while the car not moving. Intermittent fault code 29EE- lean mixture. After driving for a while when I stop the car it gives knocking sound for a while which goes off after couple of seconds.
January 6, 2016
  Followup from the Pelican Staff: Start by checking the engine for vacuum leaks and test the fuel delivery system. I would check spark, fuel and compression on all cylinders.- Nick at Pelican Parts  
fred Comments: i have a 1989 mercedes 300e gas the fan motor blow air to the floor but not the dash. do you have any idea what it could be
December 28, 2015
  Followup from the Pelican Staff: The mode doors may be faulty. Check the vacuum control to the mode door in the heater box. (if I remember correctly, yours is vacuum controlled.) - Nick at Pelican Parts  
Billy Comments: i have a W124 e320 automatic transmission. My car changes gear at high RPMs at around 2500-3000. What should i look out for Nick?
December 27, 2015
  Followup from the Pelican Staff: First check the transmission fluid level to be sure it is correct. Then check the transmission ECM for fault codes. If the system is not working properly, a fault code will be set. This will be your best bet when diagnosing. Also, it wouldn't hurt to confirm the shift patterns, as that doesn't sound too high to me. That info would be in a repair manual.

- Nick at Pelican Parts
 
montwil Comments: I have a 2002 E320 that will have a slight series of surges under normal driving conditions particularly when climbing long inclines. When climbing steep inclines or harder acceleration, the surge doesn't occur. Any suggestions?
December 22, 2015
  Followup from the Pelican Staff: Is the check engine light on? Sounds like an engine misfire. I would check spark, fuel and compression on all cylinders.
- Nick at Pelican Parts
 
Kll Comments: 2001 Mercedes-Benz s500 while idling and accelerating car has a motor shake to it, no real lost of power ,just had all spark plugs changed.
December 20, 2015
  Followup from the Pelican Staff: Is the check engine light on? Sounds like an engine misfire. I would check spark, fuel and compression on all cylinders.
- Nick at Pelican Parts
 
Bill Ri Comments: 1988 300 te, idle surges 10% of the time or less. Usually when cold or warming up. up to 1,200rpm then down then up. If I put in neutral, it goes to normal?? Any ideas?
November 30, 2015
  Followup from the Pelican Staff: Start by checking the engine for vacuum leaks. This sounds like your issue. - Nick at Pelican Parts  
DJnAtl Comments: I have a 19996 c220 and need to remove the angled tube for the secondary air injection where it connects to the exhaust manifold but cannot determine what size nut secures it and if there a special tool needed to remove it. It it hard to reach and will require an open ended tool for sure. Any help would be much appreciated.
November 25, 2015
  Followup from the Pelican Staff: It is either an E8 or E10 inverted Torx, if I remember correctly. - Nick at Pelican Parts  
DJnAtl Comments: Hello. I have a 19996 c220 and need to remove the tube for the secondary air injection where it connects to the exhaust manifold but cannot determine what size nut secures it and if there a special tool needed to remove it. I am fairly certain that blockage exists. Any help would be much appreciated.
November 24, 2015
  Followup from the Pelican Staff: The are external Torx. Likely E8 or E10. - Nick at Pelican Parts  
Haris masahat Comments: Hi!

My benz is w210 compressor year 2100. Mine theres a leaking problem that came out from the crankcase. Temperature went up high as it drain out the water pump. Can you pls help me in this as im really clueless :/
October 27, 2015
  Followup from the Pelican Staff: I would pressure test the cooling system. This is your best bet to locate the leak.
- Nick at Pelican Parts
 
Jesse Comments: Hi! My 2002 E320 looses engine power RPMs as I am driving. The engine will keep running but even if I try the accelerator-it won't rev up the RPMs. I normally have to turn the key off and start the engine up again-then the engine idles/powers normally. The CHECK ENGINE LIGHT IS NOT ON. The ABS/ESP lights are on. Miles are 188K.

I have replaced: New Air and Fuel Filters, Replaced Throttle Positioning Sensor, Replaced K40 Relay Sensors, Replaced Yaw/Rate Sensor, cleaned O2 sensors, cleaned the MAP Sensor.

I just ordered the Idle Air/Speed Sensor 0025401497. I'm loosing it! I can't figure the power loss.

I look forward to your insight. Thank you.
October 22, 2015
  Followup from the Pelican Staff: This could be a fuel delivery issue or a plugged exhaust. Sounds like something is causing an engine misfire. I would check spark, fuel and compression on all cylinders.
- Nick at Pelican Parts
 
Jesse Comments: Hello! I have a 2002 E320. The 40Amp ABS fuse #19 on the Front/Driver side Engine Comparment has no power. I power-jumped the fuse and the ABS motor turned. What Relay, or what powers up Fuse #19? I would think it only powers up when the ABS engages. By the way, ABS/ESP lights are on. Any recommendation would be highly appreciated.
October 22, 2015
  Followup from the Pelican Staff: The high pressure pump relay powers the fuse. I would start by checking for fault codes. It may he no power due to the fault code stored. - Nick at Pelican Parts  
Hassiba Comments: Hi.
I have c240 model 2002 ,with 128000 miles,i have drived my car for a long trip yesterday,approximatly 102 km,the next day i have checked engine oil ,and it,s look good,after that i have started the car she delivered a big mass of smock for one minutes and the smock disappear.i have start the car the second day at the morning and no smok are delivered,and the situation return to the normal,sometime when i start the car she deliver a smoke and sometime not.so what could be the problem? There is no oil consumption or other problem
Waiting your reply,
Best regards.
October 18, 2015
  Followup from the Pelican Staff: If not oil, it may have been fuel. Possible a faulty sensor reading at start up, causing a rich condition. - Nick at Pelican Parts  
gw Comments: I serviced my C240 2002 myself for the first time this weekend 155k miles. Changed oil, oil filter and air filter. Yesterday I got a check engine light. Took it to Autozone and they gave me these codes: PO171, PO174 and PO702. I checked fuel cap is on securely.

Wondering if I dislodged vacuum tubes when changing air filter?

I've also used the wrong type of oil - 10W30 instead of 0W40 or 5W40.

I have a slightly rough idle now too.

Any advice appreciated.


October 16, 2015
  Followup from the Pelican Staff: You likely have an air leak. I would check if the intake air duct and vacuum hoses are all connected and sealed. - Nick at Pelican Parts  
merctech36amg Comments: Is it possible to scrape all the old flaking paint from the inner valve cover and repainting it with engine paint
October 10, 2015
  Followup from the Pelican Staff: If you clean it, do not use store bought paint. Have it coated with the right paint by a professional. You don't want it flaking into your engine oil. Might be better off replacing cover. - Nick at Pelican Parts  
Jscott Comments: I have a 1997 mbz e420. I currently have a check engine light on with error 410. I took it to a mechanic and said its related to a broken air hose that goes under the throttle body. The mechanic said it was a real expensive job to replace as they would have to remove the throttle body to connect the hose. Is there any easier way to do this? I'm a broke college student who can't pay a 1200 repair bill for a 20 year old car
September 30, 2015
  Followup from the Pelican Staff: I would h ave to know what hose. If secondary air, the hoses may be most of the cost. Ask for an estimate break down. - Nick at Pelican Parts  
Shawky elhabashy Comments: Mr; nick I have 95 s320 runs very good
on drives .but no reverse . But in very cold
weather it reverse strongly for may be two
miles then there is no reverse have to wait
for one hr to reverse again . I really
consider UR opinion . Pl;what could be the
Problem & is it easy to fix ?
Some mechanic suggest to replace the trany
Also I done trany service oil , filter
Many thanks in advance
Shakie
September 26, 2015
  Followup from the Pelican Staff: Sounds to me like the transmission is worn out.

First check the transmission fluid level to be sure it is correct. Then check the transmission ECM for fault codes. If the system is not working properly, a fault code will be set. This will be your best bet when diagnosing. - Nick at Pelican Parts
 
appia Comments: 98 mercedes c230, driving normal,check engine light comes on
engine running rough, got home checked injectors, one next to fire wall has voltage but no pulse voltage. removed signal wires 1,2,3, normal. number 4 no change in rpm when removing signal wire. what could be the problem????????
September 23, 2015
  Followup from the Pelican Staff: What fault codes are there? Sounds like an engine misfire. I would check spark, fuel and compression on all cylinders.
- Nick at Pelican Parts
 
Hector Comments: I have a e320 Fuel 1999 , runs fine for a couple of miles then revs up and will not move. When it rests for a few minutes it will run again. What is the problem?
August 9, 2015
  Followup from the Pelican Staff: Hard to say. COuld be a sensor or fuel pump.
I can't help without knowing what is missing from the system when you are trying to start it. When your engine doesn’t start you’ll want to check the basics. Check spark, fuel injector pulse and fuel pressure, volume, quality and engine compression. Are there any fault codes? Once you figure out what is missing, it will be easier to diagnose.
- Nick at Pelican Parts
 
Lar23 Comments: Hi, I have a 2003 mercedes c240 with 206,000 miles that sometimes, during idle at a red light, chokes and stalls. It happens more often when the a/c is on. When the car starts to choke, I put the car in neutral or park, tap the gas and it's ok. Sometimes, if I shut the a/c, it will go back to normal. If it stalls, it starts right up. The car runs fine at speed. There are no fault codes showing. The problem seemed to have started after 2 new air filter were installed. I removed and checked the fitting of the air filter and all seems to be tight. Please help. Thanks.
August 7, 2015
  Followup from the Pelican Staff: This could be an issue with the throttle housing or the idle valve. I would suspect the idle valve first. It should be mounted to the the throttle housing. - Nick at Pelican Parts  
orcaskid Comments: I have a 95 e320 wagon. Ignition switch start malfunctions. I turn switch on and hot wire to the starter and it starts. Start switch works for a few days and the same problem occurs. I'm ready to put in a new switch but have a nagging thought this may not solve the problem and am considering a push to start switch. What do you think?
July 14, 2015
  Followup from the Pelican Staff: have you checked current at the solenoid? If too high, could be ruining the switch. - Nick at Pelican Parts  
Robert Smith Comments: SL 320 1994
Can you tell me where the Idle control valve is?
thx
July 9, 2015
  Followup from the Pelican Staff: The throttle housing on your model helps to control idle speed. - Nick at Pelican Parts  
tati Comments: Please help. Ive got a 1996 mercedes E200 petrol gasoline. In summer time when the temperature outside goes higher then 32-34 degrees Celsius my car cracks and start after 10-15 seconds. Sometimes I have to turn the key on 2-3 times and after 10-15 seconds the engine will start slowly and after 2-3 minutes will work properly and outside smell gasoline. This problem does not happened in morning, in evening, autumn, winter, spring when temperatures outside are lower. Does not happen in summer when I turn off the engine and after some minutes turn on the key, it works properly. It happened when the car is not moved for about 1 hour on high temperature outside. Many services had checked everything, sensors, electrics, fuel injection, fuel pressure, the air; computer check etc, everything and they gave up. They said they don’t understand this kind of problem.
Surfing the internet I so your website and please help me. For 3 years I have problem with my car on summer time.
Has something to do with vacuum system or ventilation system??????????
July 1, 2015
  Followup from the Pelican Staff: Could be anything from a sensor to a control module.

I can't help without knowing what is missing from the system when you are trying to start it. When your engine doesn’t start you’ll want to check the basics. Check spark, fuel injector pulse and fuel pressure, volume, quality and engine compression. Are there any fault codes? Once you figure out what is missing, it will be easier to diagnose.
- Nick at Pelican Parts
 
Bash Comments: I recently Changed a fuel filter,fuel pump,changed engine oil and blew out the air filter of my 2001 C240 MB.A day after it starts a mild shaking at idle with the brakes applied otherwise silent on P mode gear but when driven for a while it will get normalized.The second day I embarked on a journey after covering 215Km it showed Check Engine but showed no fault or malfunction ,on reaching about 305Km the sign went off,but didn't cause any problem all along.What could have happened? Any explanation please?
June 28, 2015
  Followup from the Pelican Staff: Sounds like an engine misfire. I would check spark, fuel and compression on all cylinders. Also check if you left a hose loose. - Nick at Pelican Parts  
dono Comments: Hi my 1999 e320 runs smoothly when driving but when I stop at a light it runs a little rough in Drive. If I shift to Neutral while idling at the light it runs less rough and closer to normal. Misfire or vacuum leak? Do you have write-ups on checking spark, compression and fuel on all cylinders? Thnx
June 17, 2015
  Followup from the Pelican Staff: No articles on those items. Sounds like it could be a vacuum leak. I would start there. - Nick at Pelican Parts  
saadi Comments: hello All;
i have mercedes 1998, E320 that is having a problem with the engine rpm, when i start the car in the morning the engine rpm goes to around 500 rpm and as the car warmup the rpm increase slowly to slightly above 1000 rpm and holds there, i noticed a big consumption of fuel and actually i can smell the fuel out of the car especially after a ride, another thing i noticed is when the is at P or N gear and i press the pedal to increase the rpm slowly the engine rpm increase nicely to around 1800 rpm and suddenly rpm keeps jumping between 1300 although that my foot is fixed and then when i give more fuel the car jumps to around 3000 rpm

could you please help me
June 15, 2015
  Followup from the Pelican Staff: Rough idle and fuel smell leads me to think misfire. Is the check engine light on? I would check spark, fuel and compression on all cylinders. Once you pinpoint what is missing from the scenario, you can test that part of the system.




- Nick at Pelican Parts
 
Niko Comments: I have a W210 E240.
It cruises smoothly on the road.
When i am stationary at lights or in park mode, i notice a slight shake. Please let me know what could cause this
June 8, 2015
  Followup from the Pelican Staff: Vacuum leak or misfire. Is the check engine light on? Sounds like an engine misfire. I would check spark, fuel and compression on all cylinders.
- Nick at Pelican Parts
 
Needshelpasap Comments: Hi, my transmission was just repaired, it had a leak, and was refilled. It's a 2002 Mercedes e320. Now I went through a pot hole and my rims were bent as result. My tire would drive normal when it was flat, but when I would fill the tire, my RPM would be high, and my car would jolt forward when I switched gears. Could the tire relate to the RPM? Could it be a vacuum leak? It drove normal until I had the tire damage.
May 25, 2015
  Followup from the Pelican Staff: Tire being bent unrelated to RPM fluctuation. First check the transmission fluid level to be sure it is correct.
- Nick at Pelican Parts
 
Bama64 Comments: I have a 1996 SL320 it was running great and one day I started it up and a bank of lights stayed on, The ETS, Brake and two other lights stayed on. The overdrive, speedometer, miles per gallon gauge stop working. One of the 10amp fuses on the BAS module kept blowing. We were told the ABS module was bad. We changed the ABS module and had new brake pads installed. That corrected the fuse from blowing in the BAS module. Now the brakes will not hold pressure and the same problem persist with the lights staying on. Tried bleeding the brakes and still cant pressurize the brakes. Any ideas.
May 24, 2015
  Followup from the Pelican Staff: This could be many things. A pump or defective module. I would start by checking the vehicle for fault codes. If the system is not working properly, a fault code will be set. This will be your best bet when diagnosing.
- Nick at Pelican Parts
 
DJsantanvalleyaz Comments: Greetings from Arizona. Our 1995 E300D stopped blowing cold air through the center vents. Side vents and defrost are cold. Going to check all vacuum lines. Any suggestions? 496,500 miles, 36 mpg and the thrill remains! DJ.
May 24, 2015
  Followup from the Pelican Staff: Are the center vent knobs on cold? Going by memory but I recall your model having them. The control for the knob may be faulty if so. - Nick at Pelican Parts  
Larry Comments: Hi Pelicanparts.com

I have a 1998 e320 with 350,000 miles on it and still running strong. Early morning today, I noticed that my RPM is fluctuating between 1500 and 1100 RPM. The RPM will eventually settle down to around 600 RPM once the engine is warm. I am only experiencing this during the early morning start-up.

Can somebody suggest what I need to look for? Thank you very much for great DIY tutorials. The reason my e320 is still running strong at this mileage is because of your maintenance recommendations and tutorials.

thanks,
Larry
May 14, 2015
  Followup from the Pelican Staff: Sounds like a vacuum leak. Check the intake air ducts, maf sensor seal and the intake manifold gaskets. - Nick at Pelican Parts  
Eric Comments: Hi, I have a 1998 E320. I have just replaced the headlights but I notice on the old headlights there are two vacuum hoses going to the left headlight. What do these hoses do/control? The new headlight does not have vacuum hose connections! Are the hoses necessary or can I block them off? Many thanks.
May 10, 2015
  Followup from the Pelican Staff: I'm not sure what the hoses are for. If only at one,not headlight washer.


Give our parts specialists a call at 1-888-280-7799. They can help you figure out what it is for via the parts diagram. - Nick at Pelican Parts
 
Nick Comments: I have a 1988 300ce with the M103 engine. It idles roughly in Drive or Reverse whilst being held on the brake. Whilst investigating the issue, I have discovered that the air cleaner housing that sits on top of the engine has cracks in the plastic on the underside. Could this cause a rough idle due to a vacuum leak, or is it too early in the system?
April 23, 2015
  Followup from the Pelican Staff: Yes, be sure the housing connection to the throttle housing is sealed. Check the rubber seal and boot at the intake housing to throttle, and inspect the breather hoses to the elbow. - Nick at Pelican Parts  
Shown Comments: i have a c280 1996 model. The car takes long to accelerate when you depress the accelerator pedal. Sparking sounds appear from the engine as if they are coming from under neath the engine. Also the temp is getting so high. I changed the whole wiring + new mass airflow sensor + new head gasket + new radiator + new oil cooler + new water pump + new fuel filter. The airfilter is a bit old. Also when the engine gets hot the car starts to shake when idling or when i stop.
April 23, 2015
  Followup from the Pelican Staff: The sparking may be a secondary ignition leak. Check the coils and the connections to the spark plugs. - Nick at Pelican Parts  
Curley Comments: I have a 1996sl320 the cruse works sometimes then others it dose not. What could the problem be
April 9, 2015
  Followup from the Pelican Staff: Faulty brake light switch, fault module. - Nick at Pelican Parts  
Mando Comments: Jave a 95' C280 and I was dri I g to work when I noticed steam/water coming from front of car.pulled over and heard a hissing noise with water spraying out from under intake manifold, I could not see problem from top or bottom of engine.Had it towed to some new mechanic and he said it was a coolant hose? He is going to charge me $350.00 dollars because he said he needs to remove intake manifold to access hose and he said it would take up to 4 hours to replace hose/hoses.I don't know but this seems a little pricey.What hose is directly below intake manifold and throttle body.What hoses are there and where do they go and come from? Your help is much appreciated.
April 6, 2015
  Followup from the Pelican Staff: I believe there are heater hoses that run under the intake manifold. Give our parts specialists a call at 1-888-280-7799. They can figure out what part or repair kit you need.
- Nick at Pelican Parts
 
RE Comments: 1994 E320 throttle body stop working. Replaced with used throttle body but would not accelerate after car was started. Throttle body had to be discontented and reconnected before acceleration. What's is the problem? Thanks
April 2, 2015
  Followup from the Pelican Staff: is it electronic or cable actuated throttle? How did you determine the old one was faulty? Are there any fault codes? Did you perform an adaptation using a Mercedes-Benz scan tool? - Nick at Pelican Parts  
Bill Comments: I have a 1998 C230 mercedes. Every time I go to start the engine, it takes two tries to start. The engine turns over the first time but doesn't start. The 2nd time, it starts right up. What could be causing this?
March 18, 2015
  Followup from the Pelican Staff: I can't help without knowing what is missing from the system when you are trying to start it. When your engine doesn’t start you’ll want to check the basics. Check spark, fuel injector pulse and fuel pressure, volume, quality and engine compression. Are there any fault codes? Once you figure out what is missing, it will be easier to diagnose. - Nick at Pelican Parts  
kim Comments: I have a 99 C230K. It runs real rough in P N and really rough rough in D. Car shakes bad and runs rough while driving. Replaced front motor mount and transmission mount. Code is for the secondary air injection system. Would that make my car run that rough? Also noticed a little bit of oil getting in the air filter. Also replaced the map sensor. On the secondary air injection system when you pull the little vacuum hose off it dosnt make a difference. Theres no suction or anything. Need help. Driving me nuts.....
February 24, 2015
  Followup from the Pelican Staff: Is the check engine light on? Sounds like an engine misfire. I would check spark, fuel and compression on all cylinders. - Nick at Pelican Parts  
Nooky Comments: My 2002 W210 200K has an engine rattle when pressing and lifting off the throttle. It lasts just less than a second, but at all engine and road speeds.
Start by checking you engine oil level. If ok, check engine oil pressure. If it is not engine oiling issue, try to pinpoint the rattle area and follow up with me. - Nick at Pelican Parts
Thanks - oil level OK, no adverse pressure indications. Noise coming from top end. Have taken off the cover but this doesn't make it any clearer.
February 19, 2015
  Followup from the Pelican Staff: What was engine oil pressure? - Nick at Pelican Parts  
Nooky Comments: My 2002 W210 200K has an engine rattle when pressing and lifting off the throttle. It lasts just less the a second, but at all engine and road speeds.
February 13, 2015
  Followup from the Pelican Staff: Start by checking you engine oil level. If ok, check engine oil pressure. If it is not engine oiling issue, try to pinpoint the rattle area and follow up with me. - Nick at Pelican Parts  
adel Comments: I have a benz c230 2000 when the engine is cold it stalls it doesn't change gear so i replaced the spark plugs still have same issue.
January 31, 2015
  Followup from the Pelican Staff: Could be a sensor or fuel delivery issue. I would start by checking the DME for fault codes. If the system is not working properly, a fault code will be set. This will be your best bet when diagnosing.
- Nick at Pelican Parts
 
Phil Comments: Have a 1992 190e 2.6 that only rev's higher when warm and when in park or neutral. When put in gear the engine RPM's go back down to normal and stays normal while driving . Take it out of gear and it will rev high and low rpms. Do I have a vacume leak?
January 1, 2015
  Followup from the Pelican Staff: Could be a vacuum leak or an idle control issue. Checking for vacuum leaks is a good place to start. - Nick at Pelican Parts  
Will Comments: I have a s320 1999 will not start with start error code
December 19, 2014
  Followup from the Pelican Staff: I can't help without knowing what is missing from the system when you are trying to start it. When your engine doesn’t start you’ll want to check the basics. Check spark, fuel injector pulse and fuel pressure, volume and quality. Are there any fault codes? Once you figure out what is missing, it will be easier to diagnose.
- Nick at Pelican Parts
 
nate Comments: for anyone else with the problem,I had,the throttle boot was not seated well on the throttle body.the air filter had a leak also.I believe this caused the plugs to run rich.Thus carboning up the spark plugs.
December 17, 2014
  Followup from the Pelican Staff: OK, got it. - Nick at Pelican Parts  
nate Comments: the problem is when engine gets warm,it studders,when more throttle is applied.I repaired several vacuum leaks.It feels like a bad coil.It did not start until after I found the MAP sensor had no vacuum to it.I had a newer engine put in my car,and mechanic didn't connect it,or electric smog pump.I don't use that egr looking device,have always had vacuum blocked.
December 16, 2014
  Followup from the Pelican Staff: All the emission components should be connected. Start there. Then confirm there are no duct leaks or broken hoses. Is the check engine light on? Sounds like an engine misfire. I would check spark, fuel and compression on all cylinders.
- Nick at Pelican Parts
 
oldsinner111 Comments: well it took a year for me to fix one problem,I had,nobody new nothing.I guess I'll fix this one to.
December 10, 2014
  Followup from the Pelican Staff: Whats the problem you have? - Nick at Pelican Parts  
nate Comments: one thing else,new wires,new regulator and fuel pump,new coils,plugs,maf,and new crank sensor.
December 7, 2014
  Followup from the Pelican Staff: Ok, got it. - Nick at Pelican Parts  
Nathan Comments: I have a 1999 s320 with the m104 engine.Just recent it studders when warm when I apply fuel,I have to increase speed slowly.Runs great cold.I found a hose off the smog pump,and reconnected it,ran a little better.But idle won't change when I remove oil cap.I've sprayed carb cleaner everywhere,and can't find a leak.Help.
December 7, 2014
  Followup from the Pelican Staff: Is the check engine light on? Sounds like an engine misfire. I would check spark, fuel and compression on all cylinders. - Nick at Pelican Parts  
yavcam Comments: no fault codes. could it be an OVP failure.
December 2, 2014
  Followup from the Pelican Staff: Like I stated earlier, either a large vacuum leak or a faulty idle control / throttle control item. - Nick at Pelican Parts  
brock199 Comments: well what i meant by blowing of is that it was misfire loud big poof of smoke i check front side of lower part intake manifold was in pieces which is veered because i put new intake manifold and startet i was running low RPM 1100 about 10 min i press the throttle by hand quite few times all the sudden boum pices start flying now only thing i haven't done take valve cover and clean the line and thank you so much for getting back to me so quick
November 22, 2014
  Followup from the Pelican Staff: That is a timing issue, as I mentioned in my first response. Start there. - Nick at Pelican Parts  
brock199 Comments: well it has blow off for 2 second time,lower part intake manifold behind the vacuum pump i put 3 i don't want this one go to waste to need help please !!!! well first out the blue car wont rev up so i took to garage the put new injector new throttle sensor didn't make any sense to me because it's sounds like it wasn't getting enough air i press the throttle manual and just quit any way I took home put new valve new vacuum so now put all together i'm hasten to tray and starter i think just wasting money so i need your expertise need your help i don't trust my mechanic anymore?
thank you
November 21, 2014
  Followup from the Pelican Staff: I am still not sure what is blowing off. Is it an intake duct or gasket? Check crankcase pressure. Your PCV system may be blocked. - Nick at Pelican Parts  
brock199 Comments: what causes intake manifold to blow off on mercedes benz e430 1999 well firs of all before it blow of it wasn't raving up at all change i took to dealer the change throttle sensor fuel filter and injectors
if anybody can guide me much apprecited
November 19, 2014
  Followup from the Pelican Staff: What do you mean blowing off? Popping? That would be an ignition timing issue. - Nick at Pelican Parts  
yavcam Comments: what could be causing my 1999 mercedes e240 m112 car to have high idle issues. Car idles at around 1200 revs. If I depress the accelerator even ever so slightly the revs jumps to around 2300 and stays there until I switch off the car. When restarted car idles again around 1200revs. Just like others Iam also mystified with modern ecu controlled cars. Thx in advance and keep up the good work
November 15, 2014
  Followup from the Pelican Staff: Could be a faulty throttle module or large vacuum leak. have you checked for fault codes? - Nick at Pelican Parts  
xanadu42 Comments: What a brilliant article. I really appreciate you guys making this available, though a lot of it I don't yet understand. I'd like to use a vacuum tester to see where my 104 is at in terms of mm or inches? of Hg. Can anyone recommend an inexpensive but reliable vac/fuel pressure tester? Thanks so much.
November 2, 2014
  Followup from the Pelican Staff: I like slacktube gauges. Give our parts specialists a call at 1-888-280-7799. They can help you find the right tool. - Nick at Pelican Parts  
CAMALOT5 Comments: HEY GUYS.MY 1996 E320 A/C IS INOP. WHEN I TURN IT ON EVERYTHING COME ON EXCEPT THE COND-FANS FRONT OF ENG.CHECKED ALL FUSES UNDER HOOD.WHAT SENDS POWER TO FANS.
October 28, 2014
  Followup from the Pelican Staff: The air conditioning control module activates the fan. It is located in the let rear corner of the engine compartment.Connector D; Power on pin 1, ground on pin 2. - Nick at Pelican Parts  
CAMALOT5 Comments: HEY GUYS.WHEN I TURN MY AC ON EVERYTHING WORKS BUT THE A/C FANS IN FRONT THE ENG. I CHECKED ALL THE FUSES.WHAT ELSE SENDS POWER TO THE FANS.
October 28, 2014
  Followup from the Pelican Staff: The air conditioning control module activates the fan. It is located in the let rear corner of the engine compartment.Connector D; Power on pin 1, ground on pin 2. - Nick at Pelican Parts  
theo Comments: 1993 300e benzs with 160.000 miles sat 2 years had bad gas in it I got news in it new plugs when it runs its great until it get 20/30 into the drive lose its speed cools off an go, do u think I need new pipes an cat
August 29, 2014
  Followup from the Pelican Staff: The cats would cause an issue right away. I would perform a fuel delivery system test. Check fuel pressure, volume and quality.
- Nick at Pelican Parts
 
theo Comments: 1992 300e benz stars wont stay crank
August 25, 2014
  Followup from the Pelican Staff: I can't help without knowing what is missing from the system when you are trying to start it. When your engine doesn’t start you’ll want to check the basics. Check spark, fuel injector pulse and pressure fuel, volume and quality. Are there any fault codes? Once you figure out what is missing, it will be easier to diagnose.
- Nick at Pelican Parts
 
amg28 Comments: Were can i get software
July 30, 2014
  Followup from the Pelican Staff: For what? - Nick at Pelican Parts  
amg28 Comments: I hav a 1996 c280 how do i get more power out of the engine
July 29, 2014
  Followup from the Pelican Staff: You can try software or an engine rebuild with bugger pistons. - Nick at Pelican Parts  
John Comments: I need a Central Lock Vacuum Pump for a 1997 Mercedes E420. Apparent the part number is 210 800 11 49. Also need vacuum hose connectors. Can't seem to find it on you site. Any idea of the cost?
July 22, 2014
  Followup from the Pelican Staff: Give our parts specialists a call at 1-888-280-7799 and they can help figure out which part or repair kit you need.
- Nick at Pelican Parts
 
sash Comments: Hi I have w210 220 cdi 1998 model . And when I push the break paddle rpm goes to 800 and the engine slow down.engine starts to wobble making noise. Is it problem with the ECU or is something on breaks ? , idle?
July 12, 2014
  Followup from the Pelican Staff: It could be the drop in vacuum when the brakes are applied. I would check the idle control circuit and confirm there are no vacuum leaks. - Nick at Pelican Parts  
powerhouse Comments: I hav a 96 c280 wheni floor it it has no power only goes 3000- 4000 revs thats it up hill its just sluggish please help
June 29, 2014
  Followup from the Pelican Staff: Could be a restricted exhaust or a fuel delivery issue. - Nick at Pelican Parts  
justme300e Comments:
June 23, 2014
dbarile Comments: I have a 1995 Mercedes c220. it is gas not diesel. At idle it surges up and down slightly, but as I step on the throttle, it begins to surge to the point where it can not be driven. I have already changed the main wire harness which was falling apart. I also changed the MAF sensor, but this problem persists. Can anyone give me any advice as what to do next.
June 15, 2014
  Followup from the Pelican Staff: You could have a vacuum leak.e.

I would start by checking the DME for fault codes. If the system is not working properly, a fault code will be set. This will be your best bet when diagnosing. - Nick at Pelican Parts
 
Pat Comments: 96 E320...
Rough Idling, revs up high and low, loss of power upon acceleration and then takes off. Finally today it started but wont stay started. Cuts off few seconds after starting. Any help would be gladly appreciated....
June 10, 2014
  Followup from the Pelican Staff: I can't help without knowing what is missing from the system when you are trying to start it. When your engine doesn’t start you’ll want to check the basics. Check spark, fuel injector pulse and pressure fuel, volume and quality. Are there any fault codes? Once you figure out what is missing, it will be easier to diagnose.
- Nick at Pelican Parts
 
Don Comments: I replaced the valve cover gasket victor reinz. I cleaned all contact surfaces to remove oil and debris. After reassembly and a short drive smoke was coming off the manifold at the back of the block. I couldn't see the leak but am guessing there's a leak from one of the grommets on the back of the block. There was no visible oil anywhere else around the VC. Mind you I didn't forget to install the two half round grommets at the back of the block. I did use a gasket sealer but I guess it was junk. What type/brand of sealant should I use? and if that doesn't fix the issue am I looking at a warped VC and/or something else?
June 9, 2014
  Followup from the Pelican Staff: Any RTV engine sealant should work. Did you replace the end plugs and place sealant at the areas where they join the valve cover gasket? - Nick at Pelican Parts  
1985 190e Comments: I can blow through both ends of the PCV valve, we squirted cleaning fluid in it a couple minutes ago and we can still blow through both ends. What can we do?
May 25, 2014
  Followup from the Pelican Staff: You can replace the valve.Give our parts specialists a call at 1-888-280-7799. They can help you find the right part.
- Nick at Pelican Parts
 
kbdfan Comments: I have 1995 s320 Mercedes has a leak fro the side of the engine my mechanic refused to take care of it by the way the car has 200,000 miles on it
what should I do ??????????? thank you I hope there some one the help me out thank you all
May 11, 2014
  Followup from the Pelican Staff: Not sure of what is leaking so I can't be too specific. If you cannot repair it yourself, find a mechanic who will. - Nick at Pelican Parts  
bruce Comments: i have a 1993 mercedes 300e which hasn't run in 6 years. would it harm the ignition system to crank the engine with the spark plugs out?
April 23, 2014
  Followup from the Pelican Staff: If the high voltage shorts something, yes. I would suggest grounding the ignition leads. This will prevent a short. - Nick at Pelican Parts  
Bellows Comments: I have a 1997 c180.I heard a retelling noise emitting from the engine bay. I checked the dipstick and the oil level is correct but the lifters are still noisy. what can be the problem?
April 21, 2014
  Followup from the Pelican Staff: I would check engine oil pressure. If low, the engine will be noisy. - Nick at Pelican Parts  
bruce Comments: I have a 1993 300E that has sat for 6 years. i have taken the plugs out and put oil into the cylinders. is it advisable to crank the engine with the plugs out, to get the oil pressure up ?
April 19, 2014
  Followup from the Pelican Staff: You shouldn't have to add oil into the cylinder. Cranking the engine will provide oil to the rings, if the level is correct. - Nick at Pelican Parts  
AndyK Comments: I have a 1994 C180 petrol manual car. The revs do not drop and remain high when I take my foot from the throttle. If however I change down the gears using the engine to brake then the revs will drop.
I have noticed when I start the engine from cold the tick over is now higher at around 1100rpm. I would be grateful for your advice.
March 27, 2014
  Followup from the Pelican Staff: I would check for vacuum leaks. - Nick at Pelican Parts  
rick Comments: I have a 1995 300e diesel I can not get it to shut off when I turn the key off? could it be a vacuum hose. heed some help. Rick
January 14, 2014
  Followup from the Pelican Staff: This could be the fuel cut solenoid not turning off. - Nick at Pelican Parts  
searley Comments: i have a E320CDI 2001 model and it has a vacuum fault, i have tried everything and am sick of it! cant rev the engine then sometimes it clears so it cant be a broken part or even a leak, because it cant fix itself one day and be broke again the next, could it be electrical?
September 21, 2013
  Followup from the Pelican Staff: There could also a leak in the vacuum system or the problelm could be electrical - Kerry at Pelican Parts  
Sil Comments: Where is the PVC and the THROTTLE CRUISE CONTROL MODULE ECU ELECTRONIC UNIT 210 545 01 32?
September 2, 2013
  Followup from the Pelican Staff: You need to be more specific. The 210 chassis covers a lot of years and I need to know if the car has ESP, ASR and ABS. All control units are mounted in housings underneath the hood by the firewall, usually on the passenger side. I don't know what PVC is but a plastic. Did you mean PCV? These engines do not use a positive crankcase ventilation system. The engine is under full manifold vacuum. A pipe connects the intake to the crankcase to draw out the combustion gases. What is the problem with the car? - Kerry at Pelican Parts  
wilfredo Comments: A good practice is to drop water trough all top engine area. If theere is any air entering the system it will be listen with the water/air soundnoise as pressure entering. I also have a w017, lock vacuum pump stay pushing and pilling air. Pump is ok, but lock metal stick is to strong. Even removing actuator youcan not unlock/lock with the inside small loack hander. Could be this the cause of pump forcing system?. What I do?
March 28, 2013
  Followup from the Pelican Staff: With the engine running, a light spray of water on all intake air joints and seals is a good idea. You listen for the slurp - sucking or sudden change in engine sound to locate leaks.

Your R107 lock issue sounds like the latch mechanism is corroded, seized or damaged inside. You need to remove the assembly, try soaking it in oil and exercise the latch mechanism.

roy@pelicanparts.com
 
rico Comments: Hey guys.

I own a 1993 300se 3.2liter.car VIN# is WDBGA32E0PA102424

I need a new MAF sensor for it.

Also I replaced all injectors and fuel rail, pressure regulator, fuel pump, and fuel relay, and basic 100k tune-ups like cap rotor etc.

I’m not so sure on its intake manifold.

I found a dry rotted vacuum breather hose from the air pump to bottom of intake manifold.

On the intake manifold there are 2 exact size say 3/8 male tube fittings, I would guess going back to air pump.

Not sure about which hose to buy and due i need to also put a breather hose splitter to the 2 intake manifold 3/8 male fittings.

Basically I think I need a new intake manifold and air pump because my car idles poorly and stalls.

Otherwise great compression on all cylinders, and may also new a brand new MAF sensor again.

Please respond to David Rod.

Also I can be reached at 631-949-7355 ASAP.

Most greatly appreciated.

Please call me anytime to go over and place orders with you guys.

Thank you from David Rico

Nickname: Rico

Email: davidn1621@aol.com
October 29, 2012
  Followup from the Pelican Staff: Hello David Rico

The stalling issue may be any of these issues.

http://www.peachparts.com/shopforum/general-information/128181-mb-wiring-harness-failure.html

http://www.peachparts.com/shopforum/1203058-post6.html

http://www.peachparts.com/shopforum/diy-links-parts-category/209638-ovp-relay-over-voltage-protection-links.html

http://www.peachparts.com/shopforum/tech-help/209384-cel-reader-dummies.html

http://www.peachparts.com/shopforum/diy-links-parts-category/142406-fuel-injection.html


The two common failure rubber hoses from the intake manifold are

Hose
MB# 1040100282

Hose
MB# 1040943382


These two short hoses coming from the air pump usually need to be replaced at the same time.

Hose 104 141 12 83 from shut off to check valve
Hose 104 141 13 83 from air pump to shut off valve

roy@pelicanparts.com

- whunter
 

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