johnlee

Oh woes me! The clacking noise is back. The dealer says the loose coolant pipe which they thought was the culprit had not come loose again, so basically they have no clue.........

JDude

This is directly from my repair invoice:
"2122 TEST DROVE CAR TO CK FOR NOISE AND THUMP IS PRESENT AT REAR. RAISE CAR ON HOIST AND CK REAR SUSPENSION, CK TIGHTENIG [sic] TORQUE ON A ARM, TRALING ARM, SWAR BAR, STRUT BOTTOM BOLT, REMOVED INSIDE REAR TRIM PANEL TO CK AND TIGHTEN UPPER STRUT MOUNTS TEST DROVE CAR AND NOISE IS STILL THERE. RAISE CAR AND CK ENGINE MOUNTS CROSE [sic?] MEMBER BOLTS, DRIVE AXLES INNER AND OUTER BOLTS. TEST DROVE CAR AGAIN AND NOISE STILL THERE. RAISE CAR AND TIGHTEN SUSPENSION FRAME LEFT & RT. NOISE IS NOW GONE."
I hope this helps . . .

mzn50

Im surprised with the number of us on this board alone ..with this issue, that its still a mystery to Porsche ?.. wondering if its a design defect that we have to tighten the rear suspension and bars on a regular basis.. I have a hard time believing its a assembly faux pas ..

ALEV8

I'm diagnosing this very issue currently, 06 C4 coupe. Clunk felt under car via passenger seat. Next lift usage I'm checking everything front to back underneath. I've caught stuff just in time by spot checking all four corners before take off. Don't rule out a tool loose in the engine bay.....big ol 19mm socket perhaps!? Too much $ to have Porsche ferret it all out, at least for me.

Ericson38

RAISE CAR AND TIGHTEN SUSPENSION FRAME LEFT & RT.

Rear subframe to main side rails or something...

Wonder what that is ?

We don't have a knock, but a C4 Cab could always develop one...

TexPorsche

My clunk was shock tower mounts that were trashed. The bushings were rotted, the top of the shock could move 1/4 inch inside the mount. Replace them and clunk is gone.

ALEV8

My sunroof has rattled on bad road since I've had it.

sullivas

I've had several noises that may be yours as well. Clunking from right front, turned out to be a loose control arm bolt where it connects to xmember. But, could be another control arm in your case.
The other noises were from the sunroof, after the tedious job of dropping the headliner (u need a manual) I found one of the sunroof frame bolts was finger tight and when the car twisted it made a cracking noise. I retorqued all to spec. There was also a slight bend in the sunroof track which was causing a ticking noise that would stop if I put my finger on the area while driving that would make it stop.
Funny thing was I couldn't tell where the noises were coming from so I enlisted my son to sit in the back while I drove and he was able to pinpoint the sunroof noises. I found the control arm looseness by putting up the car and feeling all the suspension parts. Now I have no noises, it was worth the effort.
Good Luck!

ALEV8

Also good advice to check all four corners on a lift. When I see that many control arms, I start getting nervous…

ALEV8

Do what I did this AM. Remove loose **** from the frunk. Extra serpentine belt, compressor, notebook, and fill with grocery bags for recycling. No more noise on bumps mostly. I am also very tired and maybe didn't pay attention. BUT sunroof LOUD!