jldog7

iTrader: (1)

My 2007 GP GXP with 48k has been the biggest money pit so far. I've been eliminating noises one at a time. Think I'm down to the last noise. I've put rear stabilizer links and rear brakes on it thinking it would be one of those. I was wrong. It's not all the time but when you go down a bumpy road it starts and won't stop till the car sits for a while. It's like a clunk that echos through the body of the car. Anybody hear of this? Maybe a rear shock or mount?

In the few months I've owned it I've replaced the intermediate steering shaft, front & rear brakes, automatic temperature sensor in dash, battery, 6 tires (two for winter), rt rear wheel bearing, rear stabilizer links. This is nuts for a car that was once owned by a 50 year old lady that had 41k on it when I got it. Got a good deal on it but damn this is getting crazy.

bigalnash

i too am having this problem i think my rear rotors are bad they look like **** and making a squealing noise especially when i backup... i would have a brake inspection done just to be safe when u replaced the brakes did u do the rotors and pads? 48k miles on these cars is prime time for brakes to be done , i hear ya on the tire thing man bullshit... eventually gonna just get two more front size rims and use 255 all around save myself the headache the performance cant be THAT different with same size tires.. dont even get me started on this car and how much of a headache it is... gotta admit when everything works tho... its a sweet ride.. somewhat...

1Fast7

My rear left dose the same thing. I got in the trunk and listen for it as i had someone drive. I thought i was strut mount so i replaced it. Not it. So it most likely is the strut itself. Shortly after the clunking and replacing the mount i could fell the tire bounce slightly when you get up about 70 so i'm sure that is it. I also had a friend the had the same problem and he took to the dealer and the told him it was struts.

heavyft

My spare tire worked loose. Once tightened down, no more clunk.

Panther427

Well GXP's didnt come with spare tires, only a air compressor and gel fix a flat stuff, but that too could have come loose.

int_53185

Mine had a rear trailing arm bushing come loose and the arm shifted to one side causing a clunk. A few other people have had that same problem.

jldog7

iTrader: (1)

Yeah I had the rotors resurfaced it's not that. I also thought that the air compressor came loose and I made sure everything was tightened down in the trunk. I can kinda hear it if I push down on the back of the car. It's odd cause it's not all the time. I took it to the dealer and they "can not duplicate concern".

Kazmaniac

We chased a clunk a few years ago - I fixed mine by replacing the exhaust hangers. They were around $8 from the dealer and an easy swap.

You can try to shake yours in the garage, if it moves they need to be replaced.

rvd9431

ive got a clunk in the rear end over small bumps going slow i can hear it, havent cared because its not a big noise

int_53185

Mine had the same clunk. Was the rear trailing arm on the right side.

GXPmattyjGXP

I have a clunk too... I figured out since the magnaflow exhaust is real close to my bumper because of the 3in tips it hits I just need to get longer exhaust hangers

Jfhghs

you need to replace the rear struts, it is the only way to get rid of the noise. I have found that you cannot replicate the noise outside of the car. The bilsteins ride good but dont last worth a ****.

Brangeta

Broken exhaust hanger?

durdinman

IT IS NOTHING THE NOISE YOU ARE HEARING IS NONE OF THE ABOVE. I JUST FIXED MINE WITH A SQUIRT OF WD40!!!!!!
I went to oriellys because i was going to just change the struts but that would have fixed it. All of a sudden i bought a can of wd40 and lifted up the dust cover on the rear struts and sprayed the shafts. There is a dust cover for the shaft of the strut at the bottom of the shaft. when it gets dried out it makes that horrible clunking noise on small bumps. I immediately went down like 30 backroads and it was fixed and i had to change my boxers cause i blew all over myself

Brian396

iTrader: (3)

Um well this is a first. I’ve seen people make there first post, I wanta go faster, or my trans is broke. But first post, I jizzed in my pants. Well ok?

ls4door

I have a GXP and obviously Bilsteins. They ride as great and handles as good as it did at 38k. I have never heard that Bilsteins don't last in fact they are supposedly the longest lasting shock/struts. Just wondering where you get that they don't last from.

GXP25

iTrader: (3)

I've been having similar noises and recently performed the WD40 trick.

It worked and my rear suspension noises are gone.

I also sprayed all of the suspension points.

Heathicus

Lube the crap out of your rear suspension joints, maybe even the shocks underneath that blue cover. I had a rear trailing arm that was bent by 15 degrees...sledgehammer took good care of that to get it back straight. Rides better. Bet that clunk is a rear suspension joint or your air compressor foam case wiggling back and forth in the trunk. I've had exhaust hangers crack and go bad on an older buick from the 80s...but you never know. Just jack the rear end of the car up (good luck with that...) and work your magic.

I also agree, it's been a money pit. But I absolutely love almost everything about the car except DOD, the restricted intake, and the God-awful 4 speed they stuck in there. The tires, eh, I've got same tires on all 4s even though the wheels are different sizes, but it's not a huge con.

Get a TEP transmission and put on a throttle body spacer with a CAI and you'd be alright lol.

SleeperGXP

I have this same issue but usually only when slowly rolling

badbrad586

Before I start I'd like to thank LS1TECH and the the people who log their issues on this site. I have had several LS1 6 4, cars and this site has provided many answers.
Just like my 04 GTO the front suspension rubber components are very soft ( rubber durometer), I think GM does this for a softer ride??? . Seeing how most of us want performance this soft rubber does not last long before ripping.
My 2008 Buick Super with 29,000 miles makes all kinds of noise front and rear.
I have replaced the steering intermediate shaft for rattling type noise felt thru the steering wheel.
I have replaced the front strut mounts due to the strut rod flopping around when I bounced the car up and down.
I have replaced the front lower control are vertical (front) bushings due to them being visually torn.
Checked the ball joints, tie rods and the sway bar links for movement, none felt. You need to remove one end of the sway bar link to check for movement, none felt.
Front noise is much less, steering way better. struts felt and looked good when they were apart, but I'm not sure if they my be making a little noise. I'm going to wait a see. I'm not sure how good the bilsteins are???
I will be looking at the rear this week and will post what I find.