Clunking noise

[pontiacman]

Hi everyone, I am new to this forum and have a 2004 Pontiac Bonneville SLE and absolutely love the thing. I have had it for 2 years now and its been very dependable. Recently about 2 or 3 months ago I started aquiring a clunking noise in the rear somewhere. It happens when I hit pot holes or bumps in the road. I have ruled out the back shocks(because they were recently replaced) and the spare tire (as I thought it may have been bouncing around). I looked the thing over underneath and it looks to be ok to me. I just want to get it fixed because its driving me crazy and I thought you guys might be able to help me, thanks.

[00Beast]

Sounds like the shocks have probably loosened up. Even a quarter turn can quiet them up. I need to re-tighten mine, as they're clunking again. I think I'm gonna put some green loc-tite on them as well. It'll take heat to get them back off, but that won't be for a while...

[pontiacman]

Ya I tried tightning both sides up already and the noise is still there. . . I am stumped . .

[00Beast]

The other thing I've seen is that the subframe mounts get loose. You could try checking them as well, I know someone put a washer in on one/some of them and that stopped a clunking noise.

[pontiacman]

Yep, I went out and checked my subframe mounts also and they are tight.

[Archon]

The one that often rusts through is the rear drivers side. The one that the emergency brake cable runs through.

Another thing to check is the rear alignment link. Jack the car up where the control arms will hang down, and see if either one pops out.

[Ken_W]

Did the noise start before your rear shocks were replaced, or after? I have noticed that several people (including myself, which is why I notice) have reported this issue starting after replacing rear shocks.

Ken_W

[pontiacman]

I replaced the back shocks about a year ago and this noise has just started about 2 or 3 months back. On my long commute to school this morning the noise seems to have gotten worse seriously. . . . .

[dpnewfie]

Did you repalce the upper shock mounts? These will cause the clunk as well.

[01bonneSC]

Did you repalce the upper shock mounts? These will cause the clunk as well.

Im surprised the other two veteran members didnt mention this in there posts....

[pontiacman]

Ya, I replaced the upper shock mounts . . . checked the nuts again also already and their tight. . .

[00Beast]

We veterans are getting forgetful in our "old age"...

[BlackHawk99]

Also check this to make sure it's tight:

http://www.pontiacbonnevilleclub.com/fo ... 34150.html

I had the same issue and had a heck of a time tracking it down.

[pontiacman]

Yep, I checked those bolts and they were tight as could be. . . .

[00Beast]

After looking at my car yesterday and tightening everything up, I've determined most of my 'clunk' is my rear deck bouncing around...

[pontiacman]

I figured out what was wrong!! . . . . I had enough and was determined to figure out the mystery clunk so I went out and took off both back tires (again) and there it was, boom, how I did not see it before amazes me but I seen that the bottom of one of my shock outside skirts had been being beat on by one of the bottom shock mounting bolts. Well than it clicked, I hadnt heard my air compressor/pump run lately. So the compressor had taken a crap and my shocks had no air in them and the compressor was a couple hundred bucks to replace, so instead I just got some new Gabriel air shocks that you can raise manually with shop air by a valve stem that I placed underneath by the spare tire. It only cost about about a quarter of what the new compressor would of. I just took her out for a cruise and no clunking, I am so happy. Thanks guys a bunch for your input and posts and trying to help me figure out my problem.

[bopguy]

Not trying to hijack this thread, but I just recently started getting a clunk after getting an alignment in the rear. How common is this? Also, this is the second alignment I have had done and the *dang* thing still pulls to the left!!!

[01bonneSC]

Did you check the compressor(ELC) fuse? Did you test the level switch?

You could have gotten a used compressor from Andrew(Harofreak00), there are cheap ways to keep your cars active suspension in tact.

[pontiacman]

Ya I checked the fuses, I didnt check the level sensor though but I figured now since what I done I dont have to worry about my compressor anymore.