My brother has a tiptronic 997tt 2009 with 35k miles, when I drove his car I noticed that when its hot and it goes from P to R there's a loud clunk - thump coming from the rear, also when going from R to D. I told him that mine didn't do that, so he took it to the dealer thinking it was the tranny and they told him it was normal at first, then when he confronted them and told them that my car didn't do that, they did further testing and blamed it on the tires Michelin PSS, same size as stock just different rims... His tires have around 7k miles.
I also notice the same clunk - thump is present when the car is hot and coming to a stop on 2nd gear, it doesn't do it all the time and only when is in regular mode, not in sport mode...

They change the oil on the tranny, and that didn't help, they reprogram the tranny and ecu and didn't help, the only thing missing is changing the tires but I don't think that will help him since everybody running non N rated tires will have the same problem.

Can somebody with a tip car check and see if it is normal? Also what do you guys think it could be? Tranny? Axle? Driveshaft. The car hasn't been abused or tracked...

Thanks

Solution on post # 17

 

Had this happen right after dealer put a new transmission in under some seal problem..... Blew the new trans within 150 miles

 

I don't really think is the transmission, I think it most be something else, when they changed the transmission oil, everything looked good in there, the tranny has no leaks and it shifts perfectly, no slippage, or loud clunk when in sports mode going up and down the gears

 

Did they check the flex disk (guibos) on the drive shaft? That can make a bit of a clunk.

 

No vibration in the car, but I'll ask if they checked it out

 

Trans mount most likely. They look ok when compressed sometimes but you take it off and you will see splits/cracks. Cheap fix hopefully.

 

I have noticed in my tip that when I go from reverse to drive I have to wait a long-seeming few seconds before I push the gas. If I go in R to D quickly i will get a discernible thump and shaking until it engages and then lurches forward. I've taken it to the dealer before and they've said every things normal (I also had my transmission replaced at 32K miles for the dreaded "seal" issue). It's pretty annoying and even sometimes embarrassing when you're making a 3 point turn and have to wait a few seconds before pushing the gas as I'm sure the other drivers are thinking look at that a--hole Porsche driver just taking his time I don't know if this is the design of the tip but by comparison in my Rover, you can immediately change from R to D and take off.

 

As mentioned...could be a tranny or even motor mount. Depending on how loud it is...it may actually just be normal...Especially if you have no other symptoms....

Good luck.
DC

 

mine does the same thing, always has since I've owned it. Have had it in the shop for the major service and still does it. Maybe it's normal..

 

I'll check mine when I back this W/e I think it does.

 

I ve noticed that on a few 997tt tip cars...happens only when hot and with car completely stopped and brake pedal pressed when I switch from d to r and viceversa...note that clunk noise does not exist when cold and as temp of the car (not ambient) rises so does the noise...I dont think any mount would alter behaviour based on oil temp...finally if I switch from d to r with vehicle rolling forward (at 1ml speed) noise is not there....weird...

 

So we still having the same issue, we switch to ps2s like the dealer requested but we are having the same issue...
It only happens in regular mode NOT in sport mode which is really weird

Any help will be greatly appreciated

J

 

I have a tip and it does the same clunk. I've been told that it's the mounts. Hopefully we get an answer to confirm that

 

Interesting...I had a tip for almost six years and never heard a transmission clunk at anytime driving the car. This includes hot and cold. 21k miles on the car and owned in Phoenix, Houston and Seattle.

 

Weird thing is it only happens when in regular mode NOT in sport mode, that's the reason I think is not mount related, maybe software related???

Anyone?

Thanks