Tiptronic problem ???

[frederic]

I just had a good tranny maintenance on my Boxster but still have a shifting problem. The automatic transmission fluid, filter and gasket were change and I still got this weird problem during normal driving condition (2500 rpm). Sometime during shifting from the 4 to the 5th gear only, the engine rev up without engaging the 5th gear and then it finally engage hard... really hard... I don't have this kind of problem when I drove at high rpm's or on any other gear change, only during smooth driving... Anybody had tiptronic problems like these... Where should I look for first...Torque converter, tranny, electronic control...? BTW I got an engine vibration always at 2000rpm at any speed on any gear... Need some advice.