New noise - need some help!!

[Barc]

My truck has almost 70,000 km on it (42,000 miles) and it has developed an irritating squeal/rattle. It sounds exactly as if it was a shot-out release bearing (my truck has the Allison) It seems to be coming from the front of the vehicle - the service department thought maybe it was one of the bearings on the belt tensioner but I have replaced that and still no luck. This "noise" is fairly intermittent - it doesn't do it all the time - it disappears for a second when you hit a bump - not nearly as noticable at idle but you can still hear it!! If anyone has any suggestions at all, I would appreciate it!!! Thanks :D

[Barc]

I almost forgot!! I also have that annoying "idle flare" It sounds exactly as if someone were tapping the accelerator pedal - it usually does it 3 or 4 times in a row and then it quits?! It IS NOT the lopey idle - I had that too but squashed that when they replaced an injector and the fuel control module!! Please tell me this "idle flare" is not the beginning of an injector pump failure?! Thanks

[DmaxMaverick]

Barc

The idle flare could be one of too many causes to list. See your dealer about this.

The noise you describe could be an idler pulley, or the tension pulley. Also check out the turbo downpipe brackets. Some of them have been known to crack/break. Look into the passenger side wheel well near the rear of the tire. Pull back the plastic so you can see the downpipe (use a flashlight). There are brackets that are welded to the pipe. Look for verticle cracks. If you don't see any right away, have someone move the exhaust pipe back and forth in front of the muffler. If you don't find cracks, I can't help you any further. Good luck.

[Barc]

Thanks Maverick - I'll check that out as soon as it quits raining and I get a chance to wash my truck!! :confused: Nothing worse than a muddy Duramax!!