128i - Automatic Transmission Slipped

[skolbe]

First post - Great Forum -

So, I was driving my 2009 - 128i (Automatic - Convertible) this weekend it has 7700 miles. I was merging on to the highway driving casually, I got onto the highway and then all of the sudden the engine started revving up at about 65 mph and the car started slowing down, felt like a clutch slipping like on a manual transmission, when I let off the gas pedal it seemed to start driving normal again. Could not get it to duplicate the problem all weekend. When it started not slipping there was no clunk or anything it just started driving normal. Thoughts are appreciated. I was not accelerating hard at all, nor do I drive this car hard.

[skolbe]

Talked to the dealer, they said unless there is an error code on the dash - there is nothing than can do.

[italiantank26]

I think I know what happened. If you quickly stepped on the gas peddle then release your foot right away there is a small delay and for some reason your engine revs up. I do this sometimes when driving, on purpouse once in a while cause its kinda funny since your in an AT.

[DBFIU]

If you floor the gas pedal, the engine will rev match. This means the engine will first rev to the predicted RPM it must attain to get to match the current speed in the gear it decides to use.

During all this, the car is not accelerating because it is not in gear, it is between shifts. If you were to let off between shifts, you would see revs climb to attempt a rev match and then it would dethrottle because you let off.

Precisely what the other guy said.

[dragon1761]

it does that when my car starts in the am. I step on the gas the rpm raises but the speed does not on drive. I usually let it drive a few seconds then step on the gas and everything is fine.