Marcel458

I recently bought a 968 Tiptronic from 1992. Now there is a diesel noise coming from the back of the engine like other people on the internet describe. This should probably be the flexplate that connects the engine with the transaxle.
Today I looked into the inspection hole and can see the flex(damper) plate has cracks, but it's still in one piece, what surprises me, because the sound is that hard.
Can someone confirm that this flexplate, although it's still in one piece, can be the cause of that rattling noise when idle or running at the same speed in low RPM, or could it be something else?

The sound is when the tip is in P, almost gone in N, and worse in D or R. When accelerating it's almost gone. The engine runs fine.

bbain

Unfortunately, I think it is your damper plate (flex plate). The damper is designed to fail, but still let the car drive to the nearest repair facility or home. Looking at your picture, that is a sizable crack in the rubber. When you get the damper out, I would bet that the crack is a tear/rip through the rubber. I've had a couple replaced and your description is exactly what my experiences were.

Also consider the amount of torque put on the damper as it is turning. The crack in the rubber will separate.

It's a pretty straight forward repair for a knowledgeable shop. Good luck!

Marcel458

Thank you for the answer, it's driving me nuts not to know the cause!
On the internet you will find so much answers like engine mounts, crankshaft (bearing) etc, but my gues was also the flexplate.
968 Tiptronic experts are hard to find in my country.

PorscheG96

You're only seeing part of the rubber disc in that photo - can you use a telescoping dental mirror to get a better look at it? It could be completely broken around the outer area that you cannot see.

Marcel458

OK, it was the damper plate:




Also the engine mounts are kind of flat, so I will replace them too.
The Tiptronic seems to have different hydraulic mounts than a manual 968, much more expensive....
Is there a real difference between these mounts?

bbain

I've only run the tip mounts in my car so I can not speak from experience. I did remember reading a post on the rennlist boards about the difference in the mounts. Here's the link:
https://rennlist.com/forums/968-foru...or-mounts.html

User 41221

I have zero regrets with spending the money on the tip mounts, it really did make a huge difference.

Marcel458

Ordered the original Porsche Tiptronic mounts just to be sure. No stock in the Netherlands, zo we have to wait until Wednesday next week.

Marcel458

Jacks911

I agree that the Tip Mounts make a Noticable difference. I had a right side bad unit when I bought the car & had them replaced - but only through Rennlist two years later did I learn the Mechanic put in the 944 turbo units not the Tip Mounts - had my "new" Indy check part numbers, and after install of the Tip Mounts I had a much more civilized 968. Very few Indy's know about this but the Porsche Pet is specific.

P.S. If you have a Tower Bar you can have a clearance issue. These new units will raise the engine 1/8 to 1/4 inch - even over New standard units - speaking from experience! With badly warn mount it will raise up more.

Marcel458

We have the damperplate, engine mounts and gearbox mount replaced and the car is driving fine now! Very smooth gear changes, and the engine shaking is completely gone.
Although it was expensive it's worth every euro.