Ok i have 2012 was driving home yesturday got into the gas ran rpms up to about 3200 before shifting but drove fine after that. stopped shut it off for awhile get back in it start driving get about 8 miles come to stop n it sounds like someone is beating on a drum under my hood. So i drove to next gravel pulled off n shut it down sitting on trailer still. No check engine light on. Any suggestions would be great.