Good morning! My Chevy Venture 2003 approx 120 thousand miles is idling high at times. It will drive fast. I can feel it speeding up even when I am not pushing on the gas. When I put the car in reverse it flys backward (I have to keep my foot on the break to back up at a safe speed) and then when I put the car in park the engine is VERY loud. Again, this does not happen all the time. Usually when I drive it over ten miles. I thought it might have something to do with the AC, but I played around with that (driving with and without the AC) and that did not factor in it. I took it to my own personal mechanic and he couldnt find anything wrong with it. I then took it to a dealership and they said they couldnt find anything wrong with after doing thier hundred dollars worth of diagnostics and said they needed it to actually be doing it…what they called a hard fail…for them to know what was going on. . They drove the car for quite some time and nothing happend. I drove it all this pass weekend and nothing happened. It might go a week or so without doing it. Thenn it does it. Usually I can turn the car off and restart it and it will be back to normal. THe check engine light is NOT on.
Any one have any clue as to what might be going on?