ITSEL33

Every morning when I start my 55 the engine makes this sound for about 5-10 minutes then once the car is warmed up its gone. Anyone else have/had this problem? I took it to the dealer they changed the supercharger belt since I just hit 40,000 miles, said it was glazed but it still squeals!
By the way the sound is coming from the front of the engine by the belts.

jandak

Sounds like a belt. Maybe the new supercharger belt is not tight enough. Belts that are not tight will cause these noises as well. If belt is ok, then another cause could be one of the pulleys is malfunctioning.

320 dreamer

s/c pulley bearing or maybe an idler bearing. using a stethoscope examine each pulley. this is a major problem if a bearing is going bad. the last you want is a bearing lunching itself inside the engine compartment. nothing but bad things happen

JustPete

Mine did/does the same thing.

I took it in and they replaced the belt and idler pulley. It stopped for about 3000 miles. Now it's back worse than before.

Seems to be a common problem of the beast.

ITSEL33

Thanks, I will get it checked out.

benz_addict

I got the same problem, it goes away after.

Say if I just ignore the problem? I honestly don't want to replace these parts every 3000miles...

BTW pete, which belt did they replace?

rick2964

It does sound like your idler pulley. Mine was doing the same thing until one day I was "gettin on it" and the pulley froze up and wiped out the supercharger belt which in turn wiped out the power steering belt. Then the belt took out the front of the engine cover. I only had 16k miles at least it was all was under warranty.

benz_addict

Hmm. That's no good. I shall replace the idler pulley & belt. Thanks!

JustPete

Yep, that's the one.

After they replaced under warranty, it would make noise for about 3-5 seconds. Now it's back full force with about 5-10 minutes of noise.

ITSEL33

The dealer is saying its the idler pulley, something about the bearings go bad. Should be ready tomorrow. They had to order the part. Hope that fixes it FOR GOOD.

rick2964

Yup thats exactly it! Glad to hear you caught it before it froze on you!

ITSEL33

Well I picked it up yesterday and started it up this morning and guess what its still making noise. I guess I will be taking her back. Can I get a refund? What a waste of time and money. You would think they would know what they are doing.

ITSEL33

Well they finally got it right. After initially changing the supercharger belt, then the idler pulley, then finally the serpentine belt the noise is gone. I made them keep it overnight and wait til I got there to start it up in the morning and finally the noise is gone!!!!

ITSEL33

This problem is back again. Its been to the dealer at least 6 times in the last yr. for this noise, most recently 6 weeks ago. That visit they changed the ac compressor, belt tensioner, and the noise was still there. Brought it back the next day then they changed the power steering pump and the noise was gone. 1 month later the noise is back again.
Anyone have any suggestions?

csumt76

[QUOTE=ITSEL33;4447168]This problem is back again. Its been to the dealer at least 6 times in the last yr. for this noise, most recently 6 weeks ago. That visit they changed the ac compressor, belt tensioner, and the noise was still there. Brought it back the next day then they changed the power steering pump and the noise was gone. 1 month later the noise is back again.
Anyone have any suggestions?[/QUOTE

That's a bit extreme... I would try cleaning all of the pulleys and idlers(compressed air) to rid them of any dirt, then possibly apply some belt dressing(mb has a paste that comes in a jar.) Typically the bearings of the a/c compressor pulley make noise, and the p/s usually only makes noise bc of low fluid level.

BlackB-Wald

Hi guys, I just wonder did any of you know that at how many miles or how long that we need to change/replace the serpentine belt? And did any of you know anything if mercedes mention this?

sambam2006

I am currently having the same issue.

When I cold start my cls 55 amg in the morning I get the squeaky noise at the front of engine pulleys and belt area. This goes away after 10-15 minutes not moving or when I start driving.

Please see the videos, please confirm if this is the noise your getting:

shardul

iTrader: (1)

replace the idlers

vvrjrlaw

Guys it's the pulley system on our cars. I purchased mine (cls55) with 63k and on startup it sounded like a washing machine. Changed every pulley and idler gear. The only bearing I didn't change was the supercharger bearing and I just picked up one of those because it doesn't need it right now. Cost me 1500 in parts and I did the work. Don't take it lightly. I had an S420 that had a light squeak for one minute after a cold start. Instead of replacing it I greased it. The pulley finally let go at 75 mph on the expressway shutting down the power steering, alternator, a/c, and water pump. Cost me 775.00 for the dealer to change the belt and the pulley I could have done for under 200.00. Fortunately when it let go my son was driving and he "muscled" the car off to the side of the road immediately and shut her down. Had it been my wife at 4'11" and under 100 lbs driving the results could have been disastrous. It's part of ownership of these cars. If you drive it make it safe. You owe it to yourself and everyone on the road. And if you are having a dealer do it ask for the old parts that way you know the parts have been changed and not greased.

M124B

Hello, I read your post, I'm not sure how long it's been up, but I'd like to point out that this may indicate an issue with the voltage regulator on your alternator. It is better taken care of sooner than later as it can leave you stranded and the sooner it's replaced the longer the new regulator will last.

Creative Steel

You need to identify what is causing the noise rather then throwing parts at it. I would start the car and make sure the noise is present and then shut it off. Remove the front serpentine belt and start the car again. If the noise is still there then it is not that belt or any of those pulleys. Then do the same for the accessory belt. Wiggle the pulleys and ensure none of them have any excessive play.

kbanks45

I'm having the same issue. I tried the water test and the sound went away for 40 seconds then came back. YouTube said when that happens, it's just a belt. But I think I will doe all 3 pulleys (2 idlers and 1 tension pully) and be done with it. The pulleys don't appear to have any play to them, but I want to fix it right the first time and be done with it... What do you guys think,

kbanks45

Update: I repaced all 3 and no problems since... It's been 2 months.... Cost $100 labor...