Curious suspension noise

[mic1981]

I noticed yesterday when getting out of my ‘08 W204 that there was some noise originating from the drivers-side rear wheel arch. What makes it curious is that if I bounce the car up and down directly above that wheel, there isn’t any noise. However, if I bounce the car by applying force above the drivers-side front wheel, after a couple of compressions the noise starts and is definitely coming from the rear. No noise from either wheel on the passenger side.

I don’t hear any noise when driving, even when going over speed bumps etc.

Any ideas what this could be?

 

[Tonygw]

very difficult to diagnose from your description but it could be the rear control arms, anti roll bar links, Or did you bounce the car with the rear parking brake on? that to could cause the noise.

Have you removed the wheel to have a look, check all the rubber bushes for cracks or wear. Could be a worn shock absorber or broken spring. Anything is possible. Really you need to have a good look around with the wheel off.

Also check the subframe for excessive rust, its a common issue on cars of this era..

 

[Petrol Pete]

have you done all of the above with the handbrake off and the car in neutral ?

 

[mic1981]

Thanks, both.

The rear subframe will be checked on the 8th when the car's in for other, non-related maintenance with my local indy specialist. It recently had a Visual Health Check at MB Warrington, but getting confirmation from them that the subframe was inspected as part of the VHC is proving challenging.

The car was in park with the parking break applied when I first noticed the noise last night, and again this morning when I was bouncing it. Interestingly, when I arrived at the office where the car park is level and I have more room to assess, I couldn't recreate the sound. I haven't had the wheel(s) off, but if the noise persists then I'll try and take a look this weekend.

 

[bolidemichael]

Is the paint on the anti roll bar perished? If so, when this rubs against other components it can sound like a squeaky mattress. A periodic application of Bilt Hamber Ferrosol lubricant, which is designed to endure within tight tolerances, keeps it at bay.