Thread: clunking noise

Hello everyone.

I have a question, not to recently I replaced the ball joints on my 2008 Pontiac Grand Prix and re lubricated the caliper guide pins and cleaned up the hardware best I could, this includes the control arms and all the bushings, I have also replaced the tie rod ends because the boots split, the struts are only a year or so old and have only 10,000 miles on them and came with lowering springs and new bearing plates, the car also received a transmission overhaul about a couple of months ago, and the rack and pinion was found loose which was making a horrible squeaking noise when i turned the wheel, that was fixed by tightening the bolts up, I have also replaced the sway bar links, and... the car has also been aligned and the exhaust re done, the mechanics didn't notice anything during the alignment or inspection that was off, but after doing the control arms and ball joints, on my first test drive I noticed something and I haven't been able to fix the issue.

Question is I am getting a clunking noise now, when I drive forward or back up the car makes sort of a "clunk clunk clunk." noise, also when braking I have noticed sometimes it will also clunk a little, I also noticed the car pulls slightly to the left when breaking.

I suspect it might be some of the brake hardware because some of the hardware on the passenger side front was pretty well warn out and I will be replacing that next break job very soon, the pads also need replaced, the bushings on the guide pins don't look too good, one of the bushings on the passenger side is literally missing, I know this is in place to reduce any noise that might be had during braking, but I am not sure that will cause the noise I am experiencing.

what do you guys think?

Re check all your bolts that touched, make sure none loosened up. Also check the lower motor mounts, it could be the motor rocking if the mounts are bad.

Originally Posted by green97

Does "all the bushings replaced" include the subframe to body bushings? Might wanna consider a look at those. Try new hardware if you think it is the brakes it's not too expensive and should be replaced with pads.

Hard to diagnose things like this over the internet.

I recently watched this https://www.youtube.com/watch?v=ZvtjnxpFRbU on brakes while bored and he had some good tips I didn't know about like silicone paste and rubber and where to use antisieze.

I think your problem may not be brake related since you said it does it going forward-does it happen while using the brakes. If brakes are sticking to the disk and the hardware is bad/missing the pad will grab at slow speeds and fall back down and click.

engine mounts replaced two years ago bolts tight

sub frame mounts tight and in good condition

control arm bushings good came with new control arm bolts tight

ball joints tight and bolts holding ball joints to control arms tight

bolts holding struts to knuckles are tight

bolts holding strut tower to sub frame are tight

bolts holding transmission mount are tight

sway bar links replaced and tight

sway bar in good condition

sway bar bushings holding sway bar to sub frame are tight booshings good

rack and pinion bolts holding rack and pinion are tight

new outer tie rods and tight

inner tie rods good

dog bones tight, bushings are good

brand new exhaust old one was cracked and rusted to hell.


I have went through the suspension with a fine tooth comb, and the only issues I find are the brake pads are warn down and need replaced, rotors may need light machining, caliper guide pin bushings are shot, and anti vibration clips are toast, in fact the pads on the driver side are warn down more than on the passenger, and the car pulls to the left slightly during hard breaking on top of this magical mystery clunk noise.

Kill it with fire and move on.....

you feel this clunk in the floor? i had a frame bolt that i swore was tight, but it needed another turn to stop my clunk after a tranny swap.

Originally Posted by spazzz

Well it looks like you should probably finish up with the brakes.
Clean the brackets up good so the new clips sit good and pads slide easy.

Are you talking about those little rubber sleeves on the end of one caliper pin?
If so toss em. I have been good without them for years.
If you decide to get new ones only use silicone with ptfe since it doesn't swell rubber. Use the silicone with PTFE anyway for your brake job.
Clean out the bracket pin holes with brake cleaner and Q-tips, over and over.

that's the plan

Originally Posted by Below Average Joe

Kill it with fire and move on.....

I really don't feel like lighting my car on fire.

Originally Posted by Scottydoggs

you feel this clunk in the floor? i had a frame bolt that i swore was tight, but it needed another turn to stop my clunk after a tranny swap.

Clunk is not felt in the floor, it can only be heard, seems to be coming from the passenger side front.

I second eliminating the rubber caliper pin bushings. These things will always swell and cause issues. Just put extra grease in there to absorb any noise that this may or may not cause.

As for the clunk have you checked the CV axles? Also look at your strut mounts. I've seen a clunk caused by the rubber separating in the mount.

brakes weren't the issue, but I did find the noise!

the noise was caused by loose bolts on the "sub frame braces." under the hood, on the passenger side just over the battery, I drove the car until the noise was bad enough I could diagnose it easier, rocking the car back and forth at this point made the noise, as I rocked back and forth I could feel the clunking which had at this point now turned into a creaky clunk as best described in the brace as i rocked the car. I discovered the bolts were in fact loose, tightening these bolts eliminated the clunk.

all checks out well now, car has no clunks or squeeks and tracks down the road straight, I also replaced the brake pads and lubed up the guide pins and put new hardware on the front brakes, found a nifty little trick to clean out the bores for the caliber guide pins, I used a scrubber for a pistol caliber gun bore cleaner! polished them out nice and shiny and then greased the living snot out of it with the approved "Caliber guide pin grease." brakes in the front now stop the car nice and smooth.