Bruce In Philly

Yea, I thought the same. I replaced the lateral control arm, sway bar links, lower control arm, and the shocks. No change although the lateral and links did eliminate other sounds lurking under there. I replaced the shocks because they were leaking and the lower control arm because I saw, when I did the shocks, the rubber was torn.

Good luck..... the best way to find control arm/suspension noise is to use chassis ears. I keep checking eBay for a set....... just never pulled the trigger.

Peace
Bruce in Philly

stevepow

Thanks - wow - so this is not going to be easy. Definitely need to find a good repro bump to test on. I have never corelated it with the sunroof - I have mine open often, hear the clunk pretty rarely, so there could be something to that. And something inherent to the car would make sense as I have heard this for a long time, before the car had much wear or age on it - and even now, I'm only at 23k miles.

Repro bump is top priority on this - like any problem: no repro, no go on a fix.

Wolfk

Hey Bruce, when you pull the headliner, can you write up a nice DIY?
I have some rattling going on up there myself.

Derek Zoolander

I have what sounds like the same clunk in my '08 C2S coupe. I hear it when my 2 rear wheels go over a bump at the same time, slow speed. I bought all 4 upper, rear control arms since the bushings were noted as cracked from my PPI. I will be installing them this weekend. Fingers crossed that it solves the noise, but no idea what else it could be.

nwGTS

Could be bad bushings on the sway bar drop links. They are known to clunk when they've failed. Give that sway bar a good tug when the car is on a lift.

semicycler

Is your subwoofer properly secured? It could be lifting and dropping going over the bumps. The Bose trim pries off easily with a plastic trim bar. Underneath is a single torx screw, maybe T30 possibly T25. Remove them and slide the subwoofer forward. Then reinstall everything making sure it's all seated properly. Or better yet, remove the subwoofer from the car temporarily and reproduce the clunking sound.

TexPorsche

I had the same issue, replaced bushing on sway arm.....nothing. Made sure shock mounts were tight, they were.

Then I convinced myself it was the shocks, removed shocks and a crap load of red debris fell out from under the wheel well from the shock mount. My shock tower mounts bushings had disintegrated. They were so trashed that they came out in pieces.

Had to order from dealer, $360 for the set. The new ones came, installed and the clunk is gone.

TexPorsche

Oh, and I forgot to mention that an independent shop told me they have never changed shock mounts, not one since 997's hit the market.

Bruce In Philly

Outside chance it is the sunroof. With the roof closed, drive over those sharp bumps... now put your hand on the roof just behind the moon roof and press... not very hard.

The sound travels through the frame and can appear to come from other places. See my repair on this roof clunk:

https://rennlist.com/forums/997-foru...fix-w-vid.html

Peace
Bruce in Philly

Mr. Clean

TTT!

I've got this too! I know it's not the subwoofer as it's still out from me doing the suspension this weekend but yes, sounds like a 2x4 is in the engine bay lol. No rattle, both tires go over sharp bump and CLUNK. I will try the hand on sunroof when I get home!!

Iceter

Problem is that they are a PITA to get to and if you replace your shocks, it makes no sense not to replace the mounts, too. There are cheaper options than Porsche mounts. When I replaced my shocks recently, my mounts weren't falling apart, but they didn't look very good--they were full of debris and didn't rotate smoothly. One of them came apart while I was messing with it, so I was glad I had bought new ones.

But it is probably true that many cars could go many more miles on the old mounts.

kkswow12

okay, i've been watching and reading along here as i have a similar noise on my 08 .1...however...the noise started after i installed a set of H&R lowering springs and it only does it when i have the little shock button engaged and the susp is even stiffer than it has been made by said installation. and it is really specific so i just don't engage the (i believe it is called)PASM, and i don't know any more than that, but it seems the noise is related to the different springs...anyone else have this situation?

TheBruce

Clunks are typically the strut mounts going bad, which is common on the 997, especially if you have Eibachs or H&Rs. I would start there.

@kkswow12 if you didnt replace those mounts when installing the H&Rs, that's your issue. Happened to me a year after I installed Eibachs. The stiffer springs accelerate the wear on the mounts. You should always replace them when putting in new struts or springs. I learned the hard way.

kkswow12

thanks bruce, it really isn't an issue cause i seldom engage the PASM and so, basically no clunk, how difficult is changing these out?at some point i will be doing them, no hurry, no worries, thanks again for the reply, cheers, kk

Mr. Clean

Boom:

https://rennlist.com/forums/997-foru...rut-mount.html