I have a 2007 Chevrolet Aveo that constantly surges when driving 55 MPH.?

[Lyle K]

The car will rev for about 3 seconds and then coast for the same amount of time. It does this constantly, most noticeable at 55 to 60 MPH. I had it in to dealer(Kruger Motors, Worthington,MN) last week , they say nothing is wrong. Car has only 3000 miles and has done this from the start. Car is getting under 30 MPG. Any Ideas?

[crazyfntony]

it's under warranty,take it back to the dealer.if you mess with it you could void the warranty

[kujo]

I know this sounds lame, but are you driving with the climate control set to defrost? Many G.M. cars have the a.c. pump oscillate off and on when you run the defroster. Try it both ways, on floor heat and defrost. If it doesn't surge when switched to floor heat, then your a.c. compressor may be going bad, thus pulling too hard, and robbing power from the engine. Most new cars have much more effecient compressors than a few years ago. On the older small engine cars, running the a.c. or defrost would lower fuel economy by as much as 20%. Good luck.