Timing Chain Problem?

[Scottyjr]

Hello Gents (& Ladies?)
My son (1 and I had success replacing the IM gasket a few months ago. It was my first foray into serious maintenance for 15 years and I was apprehensive but we didn't have much to lose on the $750 96 Calais with a 3100. Thanks to you guys the vehicle was resurected. It was a big deal to us.

Today, it just died. Cranks but won't start. Cranking is strained and I heard some backfire at the black body that feeds air to the IM. I'm thinking a timing chain (belt?) problem. I was going to remove a plug and try to detect whether the valves are moving. Can this be done? Any other methods? I searched these forums for 'bout half an hour but didn't come upon any posts that helped much. Where do you think we should go from here to identify the problem? .

Thanks - Scotty

[alerored04]

If it is the timing chain I have found that a compression check will help diagnose. That is how I discovered mine had skipped.

[sprucegagt]

Pull the oil fill cap and shine a light inside. Have someone crank the engine and see if the rocker arms are moving. No movement equals broken cam or timing chain.

[Scottyjr]

alerored04,
What can I expect to find on the compression test if the timing chain has slipped? I think, because of the strained cranking, on one cylinder I will always find compression. And will I always find no copression on the other cylinders. Am I more or less on target?

Peter,
Great idea. Quick and simple.

Thanks Guys - Scotty

[alerored04]

you will be looking to have approximately 160 psi on each cyl. Under 130 shows an issue. If the timing chain has slipped or broken the valves will be out of time causing low compression.