Greetings All,

My 95 965 is at 93K and had a timing belt change at 83K before I bought the car.

I had posted a while back concerning a squawking noise that was seemingly coming from my timing belt cover. This squawking noise was at times quite loud, always happened unexpectedly, most often at startup, and would typically "work itself out" after driving a short distance. I was thinking that high relative humidity played a role, but then even this wasn't always the rule. If I had to decribe the noise I would say that it sounded like a slipping belt, or maybe the sound of a power steering pump going bad . . . ? I traced the noise to the timing belt cover.

I took the timing belt cover off and inspected the belt. It appeared to me that there was very little clearance between the top right (facing engine) of the top back cover and the belt would contact the plastic cover, to the point that there was some gritty plastic "dust" and some wear marks on the timing belt, as well as wear on the inside of the plastic cover. Nothing severe, basically light marking or "glaze" on the outside of the belt where three plastic "fins" were contacting the belt over the right cam pulley.

I imagined that the belt rubbing on the plastic cover got it vibrating enough to squawk louder and louder while accelerating. And I was imagining that perhaps humid conditions and/or condensation might have enhanced the vibration by causing the sticky belt to grab at the plastic cover until the engine got hot enough to dry up any condensation, and allow the belt to glide across the plastic fins in a smoother and quiter manner.

I also wondered: Gee, does Volvo typically specify such tight clearances? It's just a plastic cover, after all!

Aftermarket belt? Beefier and thicker than the original belt?

Perhaps the belt tensioner needs to provide more tension than it does?

Perhaps the plastic cover that has started to sag from almost ten years of heat?

Perhaps it was just installed incorrectly at the last belt replacement?

I removed the top back cover and used two washers to shim up under the two mounting bolts in the cylinder head. Now the cover has about a millimeter more clearance and I haven't heard a squawk lately. As a matter of fact, the engine is altogher quieter at idle, as if the belt was ALWAYS rubbing to a certain degree.

But lately a post about tensioner pulley bearing going out, and cam pulleys breaking off has me wondering if there are any specific wear indicators I should be looking for.

For starters: Can anyone share with me how much deflection of the timing belt is acceptable, and where to measure it?

Any other tips or advice would be greatly appreciated.

Karl