was test driving a new ram 2500 laramie dsl today and from under the hood was a loud noise much like the turbojet fan that comes on on my 1500 laramie when idling hot. the motor had hardly been running 10-15 mins so doubt if was much over warm. my son has a '20 laramie 2500 dsl and his is as quiet as a mouse so that noise worried me enough to pass on the deal. any ideas what that could be..maybe quiets down after a while? I drove 5 or 6 miles each way down the road at 50-60 and noise was constant the whole time. nice truck otherwise