Unusual Vibration - 986 w/ TIP

[Seadweller]

What would cause a "rolling" vibration in a 986 with Tiptronic? The engine is running like a sewing machine, but every once in a while I get an off and on, rolling, heavy vibration that shakes the wheel and seats quite noticeably. Only happens in gear while stopped. I should add that the idle speed is rock solid.

I wonder if it could be related to another symptom. In manual mode, the car makes a solid shift into all gears but 2nd. Coming out of 1st into second, it shifts softly, and feels like it glides into second, rather than a crisp bump into gear. I thought perhaps this might be part of the TIP learning algorithm.

Thanks!

[Luv2Box]

I think I know what you mean about the "rolling vibration."
Mine has been doing something similar for several years and started when I installed Pedro's competition motor mount. I was prepared for occasional vibration from a stiffer mount and the shifting hasn't changed. You might inspect your motor mount to see if it has deteriorated or the trans mounts for condition.

[nicecar]

mine is caused but the a.c. compressor kicking on. It is very rare that I use the a.c. but when I do it vibrates intermittently

[Seadweller]

Thanks for the input. I'll check the motor mounts. It's definitely, completely unrelated to the A/C. It's actually a pretty aggressive vibration that cycles/pulses, with absolutely no change to the idle speed.

[Luv2Box]

Originally Posted by Seadweller

Thanks for the input. I'll check the motor mounts. It's definitely, completely unrelated to the A/C. It's actually a pretty aggressive vibration that cycles/pulses, with absolutely no change to the idle speed.

There is only one motor mount and two trans mounts.

[Smallblock454]

When did you do your last transmission ATF oil and filter change?
Is the ATF fluid level correct?

Regards
Markus

[Seadweller]

Originally Posted by Smallblock454

When did you do your last transmission ATF oil and filter change?
Is the ATF fluid level correct?

Regards
Markus

I need to go through the extensive service records that came with the car. The PO told me it was done "recently," so I assume within the last year or two. He evidently used some sort of "lifetime" fluid during the service. I'm not sure if the level is correct, but I'll need to have that checked too.

I would normally have gotten a PPI, but this car is like a time capsule, has only 36K miles on it, and the prior/original owner has maintained the car with an open checkbook and has the records that indicate such.

Maybe I'll take it to my local Indy that I've used on my prior Porsche's for a once-over.