Tiptronic Slip - Torque Converter?

[RedCobra]

Hey guys,

I have a 2000 996 C2 Cabrio Tiptronic. Maybe it was always like this and I never noticed, but now when the car in in "D", after the car shifts from 3rd to 4th (or) 4th to 5th, around 2000 RPM I see a blip in throttle, its almost like the RPM slips for like 200 or so RPM, then it climbs really strong. I havent noticed it in "M", but thats not to say it doesnt do it I guess.. My experience with engines is mostly american V8s and I know that most of those transmissions have a Tq converter lockup which is like a lockup on top of the final gear, does the 911 have something similar? or is it a problem.

If I go through the gears and only shift in high RPMs I dont see this. Its only when I leave it in auto and cruise, it slips / blips (like its downshifting)..

Thanks

[RFM]

It's indeed the lock up you feel, a typical Z.F. Tiptronic issue, it does no harm just annoying. You can check the fault codes, if there are, for piece of mind.

[RedCobra]

Thanks for the response RFM, This is the exact feeling, Even in M, I drive slowly (not flooring the throttle). 1->2->3->4 goes without incident. On both 4th and 5th gears after shifting if it was cruising @ 2000RPM I feel it blip sometimes, now if I was flooring the throttle on 4 and 5, I dont see that blip, it climbs rapidly.. the blip is about 100~200RPM to be exact happens only on part throttle cruise @ 2000RPM (nowhere else in the RPM band).

Its bizzare that the manual never mentions of a lockup converter..

I was thinking of getting 2 litres / quarts of transmission fluid and seeing if the fluid is low using the apparatus described in the Maint forum. Should I even bother?. How often does one need to flush the system?. The car has 75k miles.

[RFM]

A.T.F. fluid + filter replacement never hurts, use the approved fluid and a filling device is recommended (DIY is on the board) gearbox temp. must be 40° C. (105° F).