We've been experiencing some intermittent transmission problems with our 2006 Cooper S with a 6-Speed auto transmission.

The situation is usually something like this:

-In drive (not sport mode), the car is warmed up.
-From a standstill or rolling slowly in gear-20mph or 35kph.
-Accelerate briskly and then when the tranny shifts all you get is neutral.
-The engine revs but you get no drive.

The first two times this happened it caught my wife by total surprise so she wasn't able to make any accurate observations.

Since then we've been a bit more prepared and have been able to try some measures to get some drive:

-Shifting with the paddles didn't help. I saw 3 and then 4 on the dashboard readout but still no drive. I was merging into traffic and had to bail out into a driveway before we got toasted by a garbage truck.

-Shifting into neutral and back didn't do anything.

This has happened a handful of times but months have passed between incidents.
Brought the car to the dealership twice but since we can't replicate the problem and the car didn't throw any codes, they were at a loss to explain.

Any ideas?

 

Bump.

We have a theory. We just have to do some testing and experimenting to figure if it's the fix.