‘02 2500hd 6.0
 

Have recently developed a chirp that sounds exactly like a belt/pulley chirp. I have replaced the tensioner and the belt. Come to find out, it does it without the belt on. It doesn’t do it as soon as I start the truck up. It takes it about 25 miles or so before it starts and doesn’t do it while driving. Only hear it while idling. Thought it may be the harmonic balancer but it doesn’t wobble AT ALL. It sounds like it’s coming from the bottom of the engine area. I’ve used a stethoscope and it hasn’t helped. The only place I can barely hear it is when I put it on the motor right behind the harmonic balancer. And even then it’s not loud enough to say that’s where it’s coming from. It sounds fairly loud like it’s external but can’t say for sure. Had someone say they thought it may be flywheel or torque converter but he checked and said nothing was loose or seemed to be bad. It does speed up when I accelerate until it goes away and when I slow down it starts back and slows down with the motor. It’s driving me crazy. Can anyone give me any advice on anything i might be able to check or look for??? Thanks