GM Repair Problems? Ask GM Repair Expert Now.
is the engine light on?
would you know if it was coming from the tming chain area dn do you know if it is under warranty?
sounds to me like the timing chain may be loose or a bad guide/ tensioner which should be checked out and listened to by a mechanic because you dont want it to jump time because that can lead to further damage from your description that is what it sounds like from your discription.
please rate my service 5 stars so i can get paid for my service and if you have any further questions please dont hesitate to ask as i am still at your disposal for what ever you need in regards ***** ***** issue