I just bought a 2000 ram 1500 with 115,000. The rear end makes a muffled grinding noise on the right side when I turn and when I back up. After I turn it does it for a second or two and then stops. Almost like it is catching up with itsself. Also I drove it about 40 miles and stop for 20-30minutes and when I got back in it and went to give it gas to get on the interstate it sputter and backfired under the hood for a second or two sounded like it want to die and then ran fine when I got up to speed. It also did it again but not as bad later on after I had stopped for about 30minutes. It does not sound like the manifolds are lose though. I think it may just need a tune up but am not 100% sure any advises would be greatly appreciated.

 

For the rear end noise, could be a bearing going out. Better have a look at that, and see if you can isolate where its actually coming from. Jack up the rear, and spin things by hand. See if anything feels wonky. Does your truck have the LSD?

Do the tune up. If you don't know the last time it happened, its time for it to happen.