W220 Squeaking sound! Please Help!

[117]

Hi guys,

my W220 S500 has recently started to make a very annoying squeaking noise, which seems to be intermittent. It sounds like 2 dry surfaces rubbing together.

It sometimes happens when the car is idling, but seems to occur intermittently when travelling at all speeds. At first I thought it may be the worn drivers lower balljoint, but last week my local indy replaced this and checked the car over, and they could find nothing, but it still persists. Does anyone have any suggestions? it is driving me mad, especially in the near silence of the s class cabin!

 

[117]

Thought some more about this, the noise has only happened twice when idling (once on a chilly morning, and once just after i had washed the car) and driving at a variety of speeds the noise seems to occur consistently under light acceleration at lowish rpms....I am stumped really, I have thought
serpentine belt may be a consideration, as it looks like it is few years old?

Any suggestions gratefully received, thanks guys!

 

[momomo]

Hi, if the noise was there when your car was idling as well, then i would look at the belt and maybe the pulleys. Ho many miles has the car done?

 

[117]

Its just ticked over to 112k.....

 

[wrdcc01]

Did you ever get to the bottom of this? I had a dry surface squeek for ages and I found it this morning, the end clip holding the wood door moulding on the passenger door had just lifted enough to rub against the wood moulding on the dashboard. Only just found that now I've changed the engine mounts and anti roll bar to get rid of those noises!

Dean

 

[jefrs]

Does it start/stop when you turn the steering wheel?

In which case the sqweeel is at from PAS/Sus pump. If anti belt-slip (comes in a can) doesn't work then it's the inaccessible bearing. The Volvo used to enjoy a drop of oil on the shaft but the MB has a nylon bearing/seal so mineral oil is a no-no: I made a mistake there and made it worse. This is one occasion when WD-40 is the correct stuff to squirt (WD-40 is a de-watering fluid for throwing into naval jet turbines as they spin down, is is not a lubricant). Problem is likely a bit of grit or muck, needs cleaning away.

Similar problem can occur at water pump, alternator, etc bearings. Use correct cleaner/lubricant for the bearing.


112k on an MB means it's run-in now.