Warning: the Yukon started making a rattling & knocking noise. The GMC dealership themselves sent a letter to me stating the problem is (cold start engine knock) and there is nothing they can do and it would cost too much for a recall. They said it happens in some GMC and Chevy models and it has nothing to do with the motor, so don't worry. What! People don't pay good money for this vehicle to hear clanking noises. I found other people that had similar experiences with this suv on yahoo autos. Go check out some of their reviews before you buy.