knocking sound from front-left wheel well - it's scary.

[BenZ190D]

87-190D-2.5 with 248,000 miles:

at over 65mph on the HWY, I occasionally hear knocking sound from in front of me in the whell well. It goes away after a while. So I'm unable to determine where it exactly comes from and the cause. But when it comes, it's really scary.

Has anyone experienced this or similar? Or any hint where I should look for?

The car was recently thoroughly inspected and wheel bears replaced after I first heard the knocking sound. But my mech couldn't find anything suspicious.

thanks a million.

[slk230red]

BenZ190D,
Sounds like a front suspension problem...control arm bushing, ball joint, etc. I would also look at the Strut Mount. This is the rubber mount that goes between the front strut and the chassis, where the top of the strut connects at the top. There are three nuts that hold it in place and as it wears, the rubber cracks and should be replaced. I just replaced my struts at 74,000 miles and my rubber mounts were okay, but the Rubber Buffers and
Strut Boots were cracked and broken. My Mercedes Tech. contact informed me to make sure that the Strut Mounts were not cracked or damaged before replacing all of the other strut parts.

Good Luck,

Dave

[BenZ190D]

thanks a lot for the tip. I'll check them, although the engine and strut mounts were all recently changed, including the swaybar bushing, and the wheel bearings.

[slk230red]

If those parts were recently changed, then I would make sure that all of the nuts and bolts are tight.
And also check to see if the Strut Mounts were changed. Did the car make a knocking sound before the parts were changed?
A friend of mine that owns a MB repair shop spent a lot of time trying to isolate a squeaking noise coming from the left front wheel of customer's car. It turned out to be the bottom bolt that secures the strut wasn't properly torqued.

Good Luck,

Dave