rev raising slowly

[Jinster]

My 97 Tiptronic has been playing up the last two days in first and second gears.

Everything is fine if I just drive gently as I normally do.

But if I step on full throttle suddenly in first or second gear, the engine revvs up very slowly in first gear, and it seems like it would rev up to around 4500 and no more (maybe it'd keep going up but it was certainly too slow to wait for it). The car would be going very slowly at the same time too (out of proportion to the rev despite first gear).

In second gear, if I suddenly floor the throttle, the car would rev up, but again slower than usual, and the car can be felt jerking forward and backward - the acceleration is not smooth and towards the higher revs there might even be some deceleration as the rev goes up. When this happens, the tiptronic usually doesn't shift up into the next gear, or does so after a lot of time waiting in the higher revs.

Other than the upshifting problem which cannot be gaged when in manual mode, the slow to rev in first gear and accel/deceleration in second gear seem to happen in manual mode too.

Does anyone know what this might be due to?

Edited December 12, 2004 by Jinster

[Tool Pants]

I do not know anything about a tip other than someone with a PST2/PIWIS can read stored transmission faults.

If you had a manual transmission I would suspect the air flow sensor. Try this since it does not cost anything. Disconnect the air flow sensor and drive the car to see if there is improvement.

[Jinster]

You were right TP. It was the AFM.

Took the car into the workshop yesterday because I didn't want to risk this being a tiptronic problem. They tested it today and said it's a bad AFM and they replaced it. The only thing is - I had the AFM replaced in April this year by a different workshop. Now I am trying to get warranty claims out of the original workshop. This looks like a hard three way battle at the moment between the two workshops and Porsche with nobody wanting to claim responsibility. Major headache....