turboawd

i had this problem in my old 94 325i. while cruising at speed, the torque convertor would unock for a second, then relock. then repeat until i changed throttle positon.
bmw said the trans needed to be resealed. i guess the valve body in the trans had some issues. i never bothered to fix it, and traded it in later.

uwsc11

I am having the same problem right now and BMW tells me I need a new transmission. I am not sure that the transmission is really at fault here, after reading some of the other comments.
Anybody else experience hesitation or surging of their cars, at constant speed?
Any definite insight into what it might be?

kneemah

This is a problem I had with my 545i Auto tranny. Dealership replaced my fluid and pan which didn't fix anything. After meeting a lot of mechanics, only one knew exactly what to do.

I wish i remembered what it specifically was, but it was a body valve seal with the transmission. It cost me $800 but the transmission ran great for a year before it started happening again. So it's a short term fix, because the transmission is going to keep breaking this seal. You might have better luck.

If you're in the socal area, talk to the guys at bmw clinic.