'03 3.4 Impala: "Klunk" noise in rear

Thought it was his spare tire assembly, but I got that set correctly and the klunk is still there. There's nothing in the trunk that could be causing it now. I looked underneath the car at the exhaust pipe and the hangers look OK. I swung the pipe around to see if I could get it to hit the frame, but no luck.

Any other possibilities I'm overlooking? I haven't pulled off any wheels yet because I can't see them making this noise. It's a "thud"/"klunk" that you only hear when hitting a bump in the road.

Did you try taking the spare tire out and driving it? That is usually the culprit in "clunks" in the trunk. May not be as tight as you think when you are hitting some rough roads

No. It's locked in there good. It wasn't at first, but it is now. But even if it wasn't, there really isn't much chance it could create this "clunk" noise because the jack sits in a thick styro cradle and the spare sits on top of the styro - and the tire fits into the well with friction all the way around its circumference. Once wing-nut-ed down, nothing can really move - and even it could, it wouldn't create this noise. There is no opportunity for metal to strike metal.

Hey there,
Did you ever get that clunk noise resolved. I'm having the same issue.
Gutted the trunk, replaced all 4 struts, sway bar links, had brakes adjusted. Driving my wife crazy...thus driving me crazy.

any help would be appreciated.

thanks

canuk_bowtieguy

I had this problem on a 2000 Impala after getting it aligned. The tech adjusted the alignment, but did not tighten down one of the two bolts to lock it in place, so every time we hit a bump, this piece would flex up and down and Klunk. They tightened the bolt and it was silent. Sorry, I don't know the actual name of the piece.

canuck bowtieguy,

Actually, it DID get resolved. I was visiting my folks (it's my Dad's car) and my stay ended, so I went home. I don't hear the noise anymore.

All kidding aside, I really don't know if the klunk is still there or not. Just checked the date on this thread and I can't believe it's been TWO years!!! That means I've driven in that car the summer of 2009 and 2010 (but maybe just once each time) and I don't remember hearing the klunk on either of those trips. But it's probably still there. My father was denying its existence from the beginning, so I doubt anything was ever done about it. Good news is - my impression was it was an innocuous klunk. I'd zero in on the exhaust system. After eliminating the spare, that's where I thought I'd find the problem. It's a deep-sounding klunk noise - like the suspended muffler or exhaust pipe striking the bodyframe. But like I said previously - I didn't see any evidence of that on my Dad's car.

I would never suspect any of the parts you've had replaced. Just cannot see how any of those could cause this type of klunk. MallocArray suggests it might be alignment-related, but this noise is in the rear of the car. His car got an alignment on the REAR end???

I got an alignment on both the front and rear. One side of the rear was very bad and wore one of the tires bald on the inside edge. This was when the noise started. After they re-tightened whatever they didn't do right the first time, it was silent.

Thanks for the input everyone... Still have the clunk. Since I last posted, I took the car to the local GM dealer and asked them to find the clunk. They performed a 4 wheel alignment on the car and then put grease in the sway bar bushings. Said all fixed. sound normal. Picked up car and now the sway bar bushings squeak loudly like a squeaky runner. Way worse.
:runaround:

Frustrated, I took it home and pulled the sway bar bushings out and they looked bad. Dealer should have replaced them when they had a chance.

So, I went and bought new replacement sway bar bushings. Squeaky shoe noise is gone. Still have the clunk. Had my wife drive the car around the block a few times while I was in the trunk. it definitely is coming from right side of car. sounds like a metalic clunk like lite tapping the inside fender with a socket wrench extension.

All the money I spent and the clunk is still there. Worse thing is the car only has 45,000 miles on it and has been babied since new.

When does the clunking happen? Like only over big bumps, or even just simple dips etc?
I Had a hell of a Clunk In my 2009 LTZ (Rear ends still the same parts as 2000-05s ) that even the Dealer couldnt find and said i was nuts. I Finally Found it, Part of the Support Frame That the Rear spindle-rods Mount to was bent, and the Spindle rod it self was slaming into it over bumps. Replaced the bent Spindle rod and Straightened out the Support Frame and she Silently navigates Dips and bumps.

So, I went and bought new replacement sway bar bushings. Squeaky shoe noise is gone. Still have the clunk. Had my wife drive the car around the block a few times while I was in the trunk. it definitely is coming from right side of car. sounds like a metalic clunk like lite tapping the inside fender with a socket wrench extension.

This definitely points to a bad strut mount. You may have new struts, but I bet the mounts were reused. This is usually fine, but any mounts should be replaced if they show any signs of wear.

Hey HeMi101 and Ruley73,

Thanks for responding.... To answer... I had all 4 struts replaced with new complete units (including new mounts as part of the strut assembly). I even had the entire strut assembly on the right rear replaced within a couple of weeks with another new unit (comes with new mount). Still have the clunk.

As for when the clunk happens. When I back out of the driveway and the rear wheels hit the street you can hear it, and usully when going over bumps in the road.

As for the bent support frame and rod..wouldn't the dealer notice that when performing their 4 wheel alignment?

I would really like to get this figured out ASAP as my extended warranty runs out October 12, 2010. Would be nice to have it repaired under warranty.

Again thanks to everyone who has responded. Much appreciated.:)

Well You'd THINK they could find something like that Canuk, but if your dealership has its head up its ass as bad as mine does, Never. They looked at mine 3 times when i bought it and no one could find the noise. I Only found it recent (6 months after purchase of vehicle) by accident. Now add to that: your problem is probably no where near as Visually apparent as mine was.


Although I'm Doubtful, Check the Right Endlink for play in the ball joints. GM ones suck (Both mine had TREMENDOUS play in them with only 25,000 Miles on them), and when they go bad they causes quiet, but Multiple clunks every time you go over a single bump.

Hey HeMi101,

I had replaced the endlinks at the same time I installed the new Struts. So, that wasn't it.

HOWEVER, IT IS FIXED !:rofl:

With my warranty ending soon, I started to panick. So, I called our local CAA (affiliate of AAA) Auto Care Centre. I gave them the background on my clunk noise and asked if they have ever seen this.

He provided me with a Technical Service Bulletin # (TSB 04-06-04-066B)
Clunk/bang from rear of vehicle (replace Fuel tank and Reflash PCM)

So, with TSB in hand I went back to the dealer (who couldn't find the clunk) and provided them with the TSB. They weren't sure that was the problem. They performed the work related to the TSB.

Fixed. :rofl:

The real sad thing is that TSBs are sent to all GM dealers to assist in troubleshooting problems like this. What happened ?

Big thank-you to CAA.:wink: and a 'thanks alot' to GM :mad:

Hey HeMi101,

I had replaced the endlinks at the same time I installed the new Struts. So, that wasn't it.

HOWEVER, IT IS FIXED !:rofl:

With my warranty ending soon, I started to panick. So, I called our local CAA (affiliate of AAA) Auto Care Centre. I gave them the background on my clunk noise and asked if they have ever seen this.

He provided me with a Technical Service Bulletin # (TSB 04-06-04-066B)
Clunk/bang from rear of vehicle (replace Fuel tank and Reflash PCM)

So, with TSB in hand I went back to the dealer (who couldn't find the clunk) and provided them with the TSB. They weren't sure that was the problem. They performed the work related to the TSB.

Fixed. :rofl:

The real sad thing is that TSBs are sent to all GM dealers to assist in troubleshooting problems like this. What happened ?

Big thank-you to CAA.:wink: and a 'thanks alot' to GM :mad:

They were probably looking for a suspension or chassis-related issue. I'm willing to bet every reader of this thread was too. I'm not saying that the sound you were hearing couldn't be accurately described as a "clunk", but I wouldn't correlate the sound of fuel sloshing around in the tank with a description of "clunk". You said that it only occurs when you hit a bump. Whereas the TSB says "This noise sound is most noticeable when the vehicle is coming to a stop or during parking maneuvers." - nothing to do with bumps or sudden impacts.

I'm not trying to be rude. I'm just saying that based on your description of the issue, the majority of automotive technicians probably would have never considered that fuel sloshing around in the tank is what you were hearing.

I'm glad it's fixed, but honestly I really don't think there's anyone to blame. Although there is a TSB for the issue, I wouldn't be surprised to hear that nobody at the dealership you had it serviced at has encountered this issue before your occurrence

Hey Ruley73,
Thanks for replying. I appreciate your honesty and don't feel that you were rude in any way. I did not come to this board to be a bitcher or whiner about GM (that was not the intention). Other than one ford and one chrysler, I have owned and driven GMs the last 30 years.
I came to this board via Google hoping to figure out what the heck was wrong with the car. Taking it to my local GM garage repeatedly with no resolution, started to get under my skin. When it came to googling using words like clunk , bump, thud did not get me the results I was hoping for. Replacing all 4 struts, endlinks and sway bar bushings was costly and unaffective. My patience was worn thin.
Your right no single technician can know everything.
Thanks to all of you who did respond to my request. I do appreciate all your input.

Well on the bright side, at least It'll Ride really nice now... lol