sailor06

I have a 2007 S550 with 91,000 miles that the serpentine belt broke twice in 10 days. Both times the car was towed in the dealer for replacement.

When the serpentine belt broke the first time, the dealer reported that the cause of the belt breaking was idle pulley failure, causing damage to water pump and tensioner. Parts replaced where: TS Water Pump (Part #273-200-02-01-80); Guide Pulley (Part #272-202-00-00); and Belt Tensioner (Part #272-200-02-70).

Ten days later the serpentine belt broke again and another tow to the dealer. I have not yet picked the car up. Now the dealer tells me the car will not start. The battery was replaced a month ago after I reported that car was starting slow. Waiting to hear what the problem is now.

T.H.Carrera

yikes, how much damage to the pocket ?

gsholz

Did the car overheat?

Chris51080

I know that it's a different engine, but on my S63 I managed to shred a serpentine belt. I checked my pulleys and found that one of the plastic grooves pulleys was damaged to the point that was cutting the serpentine belt.

I would put my hands on each pulley and inspect for damage, or even debris between the grooves of a pulley.

The combination of new pulleys and a continental elite belt solved my problem.

phatisfy

Mine shredded the other day. And before all that happened. I got squeaky noise from the pulleys. Replaced it with a new one from the dealer and it snapped again. So I'm ordering a whole new pully, and belt set to see if that would solve the problem since one of the pully seem like it's going bad anyways. My car has 63k miles.

superpop

How can belt pulleys go bad at 63k miles. that is crazy, reminds me of 1970s era detriot junk that lasted 70K miles.

DaveW68

If you ever owned an early 80's Cutlass V6 that got 70k out of the original motor, then you were riding in a car with fairy dust sprinkled all over it.

KNBS550

Dave, I laugh at your comment for many reasons. I had a Cutlass Calais with a 231 V6. I think I sold it to a friend around 80k miles. It finally died from a bad transmission at 115k miles. It helped to do oil changes often. I remember having to feather the accelerator in hot weather to get it going otherwise it would die. Remember these we're carbureted engines. Back then GM didn't have its act together. Took them bankruptcy to finally put some good cars out there. Like I said, I laugh because of the memories your comment brought back to me. And your comment is true.

DaveW68

My name is actually Dave, but I've been called much worse names than Jason.

Edit: Funny that you corrected it just as I was commenting. Great minds...

KNBS550

Actually, I was going to call you Mike. But at the time I was thinking of another Super Member, Jason, and his white W221 when I was posting.

dj077

Guys... if I may, I started my car the other morning only to be met by a big red battery sign on the dash. The car only does on average 100 miles a week if any. Anyway as I was changing my battery, I noticed the serpentine belt was loose. It had fallen off and was just sitting there. I managed to get the belt back on and so far car is ok. Now I think it had been like that for awhile. My question is, will car still drive even if the belt is off?

belarus27

yes it will drive , for a minute and then overheat lol

but on a serious note , NO , because the belt runs all of the pumps that are needed for a proper operation.
so if its loose ( its either old/cracked/etc)id replace it ASAP , it kinda depends on your luck.
also check a tensioner and a water pump.

dj077

Thank you. I kind of thought the water pump was gone as I can see a bit of a mark under the bonnet when I move the car and I can see drips from what I think is the water pump. I had the car serviced with Mercedes in October then in Jan I got the coolant low warning. I topped up and again I had the warning two weeks ago. I definitely think water pump. Thanks you have confirmed what I thought

belarus27

when you be replacing the belt replace the pump and also check all of the pulleys.
good luck , and post back what was the issue.

dj077

I need a bit of help, please. Working in systems architecture did not gear me up enough for the car world. Attached is a pix and the marked item has some form of a leak. I suspect that will be the coolant pump but I may be wrong. Will someone please confirm. (Pix taken from the top)

MB wants too much money even to diagnose the issue and be it I had it serviced five months ago, I am reluctant to pay.

Also what could cause the serpentine belt to come off?
Thanks all.

belarus27

the cause of its coming off can be stretched/cracked/old belt or one of the components that its running could be the cause (if its not operating right)
maybe a belt tensioner... etc
a lot of possible scenarios

dj077

Hmmm ok. Could you confirm the coolant pump in the picture, please...

belarus27

not the pro at these but looks right to me

https://mbonlineparts.com/parts/2007...agramCallOut=6


http://www.ebay.com/itm/Mercedes-Benz-2732000201-ENGINE-WATER-PUMP-KOOLMAN-NEW-CL550-CLK550-G450-G550-/111831084486?hash=item1a09a6edc6:g:8eAAAOSwbdpWUn8 w&vxp=mtr

dj077

You are a star. thanks for your help

alx

it is your water pump.

...but... dont just buy a new pump. observe carefully where it leaks from. it could be a hose or a hose fastener.

dj077

That's wonderful. thanks. Unfortunately I cannot get under the car but looks like its somewhere under the pump. It still baffles me as to how the belt will fall of because of the water pump. Anyway I am getting a new pump and a new belt and betting MB to fix it. I hope that fixes the issue.