so here we go with another problem with the Cayenne...

This only happens when the car is cold. As soon as the car starts moving it feels like the PSM was off (thought it's not OFF) as it is very jumpy and agressive. Then if I accelerate somewhat hard and right away let go of the throttle, the car continues to accelerate for about 5 seconds!! WTF?? As soon as the new gear engages while accelerating by itself, I can hear a loud thump coming from the front.

As soon as the car warms up a minute or two after this, the car runs fine and back to normal.

It's an 05 Cayenne S with about 64k miles

Any advise before I get raped at Porsche service??

 

If it is completely cold, maybe let it run for a minute or two until secondary air turns off. They can be a bit finicky when first getting going from a COLD start. They will also start off in first gear typically when in this scenario. If I start mine and it is idling about 1100RPM while secondary air is going, I always wait for it to settle down before setting off, usually landing about 800-900 RPM.

 

when it warm it should be in 2 gear at start....use to have the this car man in the winter when it start up I feel like the engine gone blow up,the engine knocking so loud like u take a hammer n bang on it that y i got rid of it...many time brought it to the dealer but never fix

 

If you have any dash lights on that should not be, go to autozone or walmart and buy one of the $40 - $80 ODB-ii port scanners and check your codes (cheaper then a dealer visit). If you have no codes, you might want to hit up the dealer. First place I would look is the TPS. If the sensor is bad, it can act wonky. If the sensor is working but being fed bad data (out of range data) it could also think that it needs to kick the rpms. Anyway, that's a little spitballin and I could be off - check your codes first - its cheap and easy.