I have a 1989 GMC Sierra 1500 with a 350. My belt tensioner had a bad bearing and was replaced. A week or so later, I started to hear a rattling noise from the engine bay, mostly when in drive or reverse. The noise is coming from the belt tensioner. When I put force on the tensioner, the noise quit. Could this be a bad new tensioner or maybe a stretched belt? Pretty cheap item, so I can always replace it just to see.