Why does my engine rev sometimes when idling?
When my foot isn't on the gas and the car is not in gear (it has a manual transmission), the engine will do short revs every 1 or 2 seconds. Any idea what this could be? The car also has a blown head gasket. Could that have been the problem? It's in the shop right now getting repaired for that, so we'll see if the problem goes away after we fix that.