My car will suddenly rev up while I am driving about 40 to 60 MPH. It will go to about 4-5 rpm's. It will go in for a few seconds can and can not be at same time as when the car down shifts, it will then go back to normal. The first time it happened was on a record heat day. I was running the air conditioner, but temperature gauge was normal. I may add that I live in the desert and it gets about 115 degrees.
Jul 3, 2016 at 3:22 PM
