Does anyone know what to look for when driving at a constant speed the transmission starts revving on its own? It's slight but you can feel it. And you can watch the RPM's going up and down. Then it just stops (not the car but the revving).

I was going to check the transmission fluid but apparently GM didn't make that very easy for the consumer. As far as I can tell, you must have to check it from underneath the vehicle, or else go to the dealer. However it is not leaking any trans fluid.

Anyone else have these problems?

Thanks in advance

I had the same issue, my car is actually in the shop still getting the transmission rebuilt.

Wow, I hope I don't have to have that done! I had a friend of mine who is an ASE certified master mechanic drive it last night and he thinks it might be the torque convertor unlocking the overdrive. He did however suggest having a transmission flush done first, so I'm going to do that. Otherwise I'm going to document some things over the next week and let him know. I'll post back when I know for sure.

Sorry it took so long to get back to this, my car was at the dealer for two weeks for a warranty issue. However, I was finally able to get a transmission flush yesterday. I'm happy to say that the revving problem has NOT happened since the flush. But it is still too early to tell. If I have any other problems I'll let you know.