[MCL968]

About two weeks ago, I started the 968 in anticipation of the drive to work (often the only fun time of the morning) and a peculiar sound came from the engine. It was a random "ping" like something hitting the blades of a fan. I shut the engine down. Started it again, and the ping became more frequent. Shut it down again and drove the Volvo to work.

 

Returned home, started her up again, and the ping turned into a growl, then it sounded like a bunch of marbles in a blender. Shut it off, called mechanic, then AAA.

 

Mechanic found one of the belt rollers had disintegrated. Plastic pieces all over the place. He replaced the lower quality rollers with OEM parts, and the Dayco belts with Gates. The rollers were only a few years old, and it was his belief that the Dayco belts were too stiff and they required more tension to keep the balance shafts from jumping. This, combined with the lower quality rollers, resulted in premature failure.

 

So, the moral of the story is (again) use Gates belts. Even though Dayton/Dayco is a good second choice, they are still not as good as the Gates. The engine is so much quieter now, and I suspect I will not have any more trouble with the balance shafts jumping teeth.

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[Bulti]

So you know which brand of rollers?

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[Ryan]

You dodged a bullet there my friend.

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[kwikt]

Interesting! Which manufacturer of the old. I thought INA was the only supplier!!! 

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[MCL968]

Interesting! Which manufacturer of the old. I thought INA was the only supplier!!! 

I have to pull the receipt and see if it specifies the part supplier. They were installed by the previous owner's shop in Los Angeles before I purchased the car a three years ago.

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[Bulti]

Maybe the bearing was already bad, maybe they dropped the roller before installation...

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[MCL968]

The receipt only lists the part number, not the manufacturer, so no help there. It's possible the rollers were damaged, it's also possible that the stiff belts precipitated a situation that would not have occurred with more compliant belts. Either way, the problem is solved and the lesson learned. Still, the sound was unlike anything I had ever experienced.

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[Gotter]

I had the exact same thing happen to me about 6 years ago. .25 miles from getting home.  And most of the .25 miles is down hill.  I got VERY lucky.

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