My father bought a 2011 Aveo new and has said it idles to high since the day he brought it home...it has the eco-tech engine with a standard shift...he brought it up my drive (15% grade for about 150 yards) the other day and never touched the throttle...it idled up my drive at 1000 rpm then at the top he pushed the clutch and it went straight to 800 rpm...why does it do this...anyone else have this happen? Thanks for your time