Tapping noise near muffler on '90 300CE? - PeachParts Mercedes-Benz Forum

#1 10-26-2002, 10:42 PM

I have recently experienced some sort of tapping noise on the left rear of my '90 300CE with 148K miles. It only occurs upon acceleration from a stop, and is quite noisy. Once up to speed, I no longer hear the tapping or knocking noise. I got under car to see if the muffler hangers were broken, or something obvious would be visible to this novice. No such luck. Anybody have an idea? Thanks in advance.

Mike

jsmith · #2 10-26-2002, 10:56 PM

differential mounts? they look like two rubber plugs in the subframe behind the differential housing. move the differential up and down and you'll see right away if they are shot or not...

ILUVMILS · #3 10-27-2002, 08:36 AM

Driveshaft center support and bearing.

psfred · #4 10-27-2002, 01:03 PM

Is the little rubber bump stop still in place on the rear hanger? If not, the muffler may be tapping on the hanger under hard acceleration. I'd check the engine and tranny mounts, too, as if they are bad, the allow the exhaust to shake more than it should.

Peter

#5 10-27-2002, 09:14 PM

Now I have some good ideas to check tomorrow morning. What a great bunch of members are on this list! I will advise what I find.

Mike

Speedrxer · #6 11-21-2002, 12:17 AM

I have a 90 CE with the same clunking at the driver's side rear.
Car was checked for bad bushings, parkiing brakes, etc but nothing appears to be bad. Nosie appears & disspears.
Did the original person starting this post find the problem.

Thanks

jsmith · #7 11-21-2002, 07:31 AM

if it is not associated with gear shifting / acceleration, this sort of clunking is caused by the sway bar links in the w124. see if you can induce it by swerving from side to side in an empty parking lot. that's how i decided that mine were shot even though they looked ok and didn't budge when they were checked up on a lift.

#8 11-21-2002, 11:52 AM

I checked it out visually after the early round of suggestions, but could not determine myself the nature of the problem. I need to have it checked out by a pro, but I am thinking that it is a problem of the driveshaft center support and bearing or Jsmith's earlier suggestion of differential mounts. It looked to me like differential mounts would most likely be the problem, as they plugs look very old and worn out. But when I tried to move the differential up and down, I couldn't budge it. I will also try out Jsmith's latest suggestion, and appreciate all the comments very much. My noise is not really a "clunking" type of noise, but more like a hard tapping noise. It also comes and goes, and sounds exactly like the problem of Speedrxer. I am going to see my independent about this very shortly. Thanks.

Mike

Speedrxer · #9 11-21-2002, 09:34 PM

Thanks Jsmith. I will look at the swaybar links.
However, I tryed swevering the car that day it may the nosie and could not reproduce it. The car was put on the lift and all the various mounts & bushings looked find. The only thing done was the Ebrake was readjusted (no metal grindings was found).
The noise was acutally a tak, tak noise like the muffler was banging against something which got louder as I drove it. It seemed to start from a slow acceleration and disspeared with higher speeds. This occurred a few weeks ago and dissapeared.
It was so loud I slowly drove it to my friends shop thinking something in the drivetrain was going to blow. The noise(not as loud) appeared briefly a few days ago and went away again. I brought it to another mechanic & no problem was found. I wish whatever it is would keep making the noise & not suddenly fail and strand me on the freeway.
It could be the CV joints but they are expensive to replace just on a hunch. Thanks for the replys. I will post the problem once I pinpoint it.

#10 11-21-2002, 10:59 PM

We have exactly the same car, model, and year. After reading your latest description of your problem, I can say that my car's symptoms are identical. Let us keep in touch until we figure this one out. Thanks.

Mike

JCE · #11 11-21-2002, 11:26 PM

This old thread may help:

Rattle quiz

Alternatively, I have heard that a bad acumulator in the fuel system could make a rattling sound on acceleration/start up.

Speedrxer · #12 11-28-2002, 02:33 AM

My clicking noise reappeared on my CE again on a constant basis.
After looking over the possible problem areas, my mechanic decided to pull back the axel boot and inject some CV grease into it. This seemed to have solved the problem for now. If the noise reapears, I'm going to replace the CV joints. Searched the postings for Axel Shafts & this seemed to be the problem.