Yesterday night was driving down motorway and accelerated from around 70ish up with foot flat on pedal.
I heard the car rev funnily from around 2k to 4k and then to around 5k but all of a sudden the revs dropped back to about 3k and startes climbing normally again.
What can cause this proplem or can it just be a one-off? It didn't happen again last night and the car was at optimum temperature.
Cheers for advice