Hi All, just wondering if any of you have had this problem with your 996tt and if so what was the remedy. The noise comes when cruising and you lightly tap the accelerator or tap the brake. Sounds like i have a can of WD40 in the trunk, but its sure as hell not that! No noise at all when turning, so i have ruled out CV for now. I have also replaced the control arms and the shocks.

Thanks for your help.

 

try some slaloming left to right so you can rule out a falling wheel bearing also ( if you haven't already ). if the noise occurs when you turn in one direction one of your wheel bearings on the opposite ( IIRC?) side of your turn will be toast.

but this is my ( though improbable ) WAG. it's unlikely to be a wheel bearing based upon you hearing it with throttle input or brakes engagement. sorry , that's all i could hazard as a guess. good luck w it.

 

Is it just a single clunk in each instance? If so, it might be a bushing or a mount that you are hearing where it has eroded away and you are hearing the metal on metal clunk.

 

^ good advice.. also..falling old/crumbling ( the rubber bits ) top mounts will make all kinds of "clunking" noises under a variety of road conditions. good call.

 

best way is to lift the car up so its of the ground, and rotate the wheels--- maybe axle. sounds like something is lose- front upper mounts shot? maybe diff - rear bushings shot?

 

I have the same issue. I can only hear it when I lightly apply throttle in 5th or 6th gear with the windows closed and the radio off around 50-55mph. Haven't noticed it when applying the brakes. I've had my car on my lift all winter and checked all bushings, mounts, wheel bearings, etc. They are all fine. I think my sound is in the trans or the front diff.

 

Motor mounts?

 

Since I can't experience the clunk your car generates I can't say it is normal, but the drive train has some slack. Gears run with some clearance and the same goes for the bearings.

Under some conditions the slack, free play, causes a clunk. I hear it from my Turbo once in a while and I have heard from my other cars, too.

If the noise is not the normal noise from drive train slack consider the DMF. The DMF cushioning feature can fail and the flywheel can clunk. You probably can produce this with the car stopped and just working the clutch to engage/disengage the clutch.

'course, if the noise is not normal others have offered up some good guesses/ideas. Now it is up to you to supply the answer.

 

Mine might be totally normal. The fact that I have to have the windows up at a specific speed range and lower RPMs (i.e. quieter) and listen for it means it's really not much noise at all. I don't have another Turbo to compare it to though. When I was test driving my car I didn't notice it. In fact it took about 500 miles for me to notice it the first time.

 

Trans mount? How old is it?

 

fella's.. there is NO "normal" *clunk* in these cars. unless one is incapable of operating their clutch properly. for if true, one could theoretically clunk around all day.

 

Thank you all for replying with suggestions. The noise is definitely not normal. It is loud and annoying and the reverberations can be felt through the steering wheel and your ***. It is a clunk when on the accelerator and clunk when you take your foot off the accelerator. It is definitely not related to turning or going over bumps. I have already replaced the transmission mount.

Has anyone replaced the front diff mounts? Are they something that is likely to wear out?

 

+1 on checking the transmission mount. I had a problem similar to your description and it ended up being the transmission mount.

 

That is NOT normal, and much more obvious than the sound I'm hearing with my car. It seems to be drivetrain related. Since you already addressed the trans mount, you could check out the front diff mounts (mine have 70K miles and are in perfect shape), and I would also check the engine mounts. Assuming you don't find anything wrong with those other drivetrain mounting points, I'd probably seek the opinion of an experienced Porsche mechanic. Doesn't have to be at a dealer, just someone who has worked on these cars for a while. Good luck.

 

Guess its the flywheel or clutch. But i had this sound in my 996 targa and now in my 996 tt. Guess its normal.