# 2010 Cruze Diesel Drive Belt Jumping Around and Making Noise



## Buzz (Aug 24, 2015)

My engine drive belt jumps around and makes a dull thumping noise at idle but give it some revs and it's smooth and quiet.
I have replaced the tensioner, idler pully and belt and the issue still remains.
I checked the pulleys on the power steering, air con pump, alternator and crank and there's no side bearing movement and all spin smoothly.
To be 100% sure, I completely removed the drive belt and ran the engine at idle and there's no noise. I did this to be sure it's not the timing belt or related components.
Engine has done 300,000 kms and hasn't missed a beat. It still runs and drives perfectly.
Any clues ? Check out the video.
0FFDB3F4-8D47-4952-954D-7C02F6B0AC09 (1).mp4


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## Johnny B (Jun 4, 2019)

I would check the overrunning pulley on the alternator first.


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## Buzz (Aug 24, 2015)

Hey Johnny B, thanks for your input. I think you are spot on. Checked the overrunning pulley today by holding the alternator fan still and I was unable to turn the pulley either way so it was working like a solid pulley rather than an overrunning pulley. I have ordered a new pulley Dayco OAP018 and 33 spline tool Dayco OAPT33 and will let you know how I go.


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## Johnny B (Jun 4, 2019)

Buzz said:


> Hey Johnny B, thanks for your input. I think you are spot on.


Don't forget to add me to the Christmas card list.


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## Buzz (Aug 24, 2015)

I replaced the alternator overrunning pulley yesterday and everything is all back to normal. Thanks for the tip - you are now top of my Christmas card list !
For the record, to pull the alternator out from a Gen 1 diesel requires removal of the the following - airbox, intake pipe, plastic inner guard, plastic undercar guard (front), drive belt, radiator fans/shroud and associated wiring. I also drained the radiator to remove the top hose and tied the aircon pipes up as high as possible for additional access.


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