Vibration at idle

[Greg McCall]

Brothers Duramax has just started to have a small vibration when truck is stopped at red light etc. Rear view mirror and outside mirror is mildly shacking and he can feel a slight vibration in the steering wheel. Vibration stops as soon as he drives away from the stop. Truck has 42,000 miles.
Anyone experience this or know what this may be ?

[mark45678]

put a good dose of injector cleaner in it for 1~2 tank fulls of fuel see it that helps . I have found mine will some times do this If it gets a poor quality batch of fuel!

[roegs]

Mine did the same when I was running Total Power. Is he running any additives? If so, he may want to try a tank without any.

[crafty]

Is this truck a 6 speed or an auto? If it had a 6 speed I would ckeck into the flywheel. Just before i had my flywheel replaced I had a very noticable vibration at idle. :D :D :D

[Greg McCall]

Truck is an automatic. Don't know about additives but I will ask.

[Alan Lutz]

The problem might very well be the serpentine belt and or the tensioning pulley. I recently had the same symptoms. When I looked at the belt at idle the tensioner was jumping up and down pretty good. Replaced the belt with a Gatorback and installed a new tensioner at the same time. Problem cured but I don't know which one did it. Good luck.

[jlars]

Alan...same problem here. Did you have to replace the full tensioner assembly or just the part that engages the belt?