Hi all,

My W203 C200 Kompressor (2001, M111.955 engine) has a noisy belt.
For the life of me I've tried to find the relevant DIY article on pelicanparts (also on the internet in general), but haven't found the right ones! Pelican parts W203 section focuses on the M112 variant of the W203 model.


I've also tried searching the R170 section, which I think uses the same engine, but it doesn't have the same pictures as my current engine which looks like this:


Searching online, the problem is likely one of the following:
-belt tensioner pulley
-idler pulley
-steering pump
-aircon compressor pump


I am facing a couple of problems:

1. Can't find repair manual for this particular car / engine combi.

2. How do I find the right parts to give me the parts specific to my model?

I've been searching online for a few hours to no avail!

Appreciate any guidance.

Thanks!

Mist some water on the belt while the engine is running, if the noise goes away you have a belt problem. If no change in noise something else is the issue.

If there was no change in noise, remove the belt and start engine. If noise is gone, you have an accessory has a problem. If noise still there, you have an engine problem.

If water in step one made the noise go away, sand the flat pulleys with 80 grit working in a X fashion. Also look at the belt for a number sticker, if hard and slippery, lightly sand this area. What happens is the belt slides across the flat pulley making a squeek noise.

While the belt is off the accessories and feel for roughness. Also spin the clutch on the super charger, I think there is a coupler in the front nose that fails. Note, the super charger runs when the engine is cold to provide air to the cat converter so you could have a super charger noise at idle.

Stethoscope or rubber hose can help isolate the source. Be careful of the fan and other moving parts.

__________________
Prost!

I have the 98 C230 W202 with M111.974. I would guess the serpentine belt mounts about the same (I could be wrong of course). The main difference is likely that the access is harder because of the duct running across the front of the engine for the compressor system.

Assuming the two engines are the same then this video might help you locate and remove/replace the belt:

https://www.youtube.com/watch?v=xSDmtxilH1c

__________________
1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

Thanks so much for the replies, and very good trouble shooting tips!

To get full access to the belt, I would need to remove this part (yellow circle)



Would anyone know of any video / manual I could get for disassembly instructions? I think once I can get that part (yellow circle) removed, I should be able to navigate the belt / accessories.

So far, I've ordered a Haynes Manual, as well as a Mercedes WIS DVD (ebay). Would those help with disassembly instructions?


Some things I've noticed:
--> When its raining, sound gets louder?? (Will try testing this out by spraying water)
--> Sounds gets louder as I rev higher! (Sorry if this is a newbie observation).
--> Sound is there whether or not A/C is on or off.

That's the air filter housing. It "should" be easy to remove but I don't know.

As far as Haynes, if it is the one that covers the C230K then it should help.

I have no knowledge of the DVD

__________________
1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

It's simple. Undo star head bolt on top of charge tube (far right in your circled area). Next directly in front of airbox on right side move silver retaining clip handle counter clockwise to release air intake pipe. Next loosen clamp on left side is airbox. Last pull up on right side to release mounting pylon and the same on left side. The airbox will lift directly up and out of your way. The rest is straightforward mechanics. If you are unsure you should seek professional mechanic help and advice.

Yep, dampness makes for a louder " cracking " sound , ( not sure why ) wetting with water will lubricate the belt temporarily making the noise go away. Don't be afraid to get the belt wet, it will dry off.

Observation is just fine.

This lets us know that the compressor is OK, but the clutch is still suspect. However, given more noise then damp I'm voting for glazed flat pulleys / belt. What ever you do, _DO NOT_ use belt dressing, this sticky stuff makes a real mess, won't last and, then the noise returns it will be far worse!

This flat belt noise is common across all cars that use flat belts and can even occur with very hard old style V belts.

Thanks everyone for the inputs!

I managed to take out the airbox, and undo the belt.

After playing around with the separate components, I realise that the steering pump is main source of rattling noise.

Pushing the steering pump pulley back and forth, there is a bit of play. I suspect the bearings are shot. Other pulleys are quite solid.

A couple of questions:

1. Would it be best to change the ENTIRE steering pump? Or is there a way to just change the bearing / pulley portion?

2. Is removal / reinstallation of the steering pump a big job? Or a simple plug / play thingy?

This is my first time working on my car and thanks to help from this forum, I actually think I might be able to DIY my problem!

Thanks again!

By using your word for dealership, you have just lost my further assistance and will stumble in the dark trying to fix this. . . . .

97 SL320,

Sincere apologies if my poor choice of words has offended you. I have deleted it from my post.

In my case, my dealership has charged me over $4k for the last 2 jobs, which involved changing out of parts which were not even broken. (The problem resurfaced 2 months later). The offensive word I used was learned from other forum threads talking about similar experiences.

That being said, I would agree that my bad experience does not mean that all dealerships are bad. And hence, it is not right to label all of them in this offensive way.

Thanks anyway for your past advice / tips. It is much appreciated.