Isolating a Strong, Intermittent Vibration
 

I'm trying to isolate a strong vibration occurring with my '98 Boxster with Tiptronic. The engine is running like a sewing machine, but I'm getting a heavy, pulsing vibration (off and on) that shakes the wheel and seats quite noticeably. It only happens in gear while stopped, after the car has warmed up. I should add that the idle speed is rock solid, so the vibration is not associated with an idle "seeking" issue. It gives the sensation of the pulsing vibration you feel when flying a twin turbo-prop aircraft.

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 2nd, 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, but I'm not sure.

I'm new to the Boxster and Tiptronic transmission, as I'm a prior 911/Carrera owner. Any input would be most appreciated.

Thanks!

I should add that the transmission was serviced a little over a year ago, and in 2011, an LN Engineering IMS bearing kit was installed.

Since the TIP defaults to 2nd gear to start from rest and you seem to have trouble shifting to 2nd I'd be suspicious of the trans.

What was done to the transmission when it was serviced? How many miles ago? Has it always done that since the service?

Neither my '99 TIP nor my '01S TIP did anything like you are describing.

Thanks for the reply. I just bought the car, and the transmission service (fluid change and filter) was done about 14 months ago. During that period, the car was driven only 500 miles or so.

I was considering having the TIP learning module cleared so it will re-learn my driving techniques. I'm not sure if that would answer the situation shifting into 2nd. The car has around 37K miles.