how do you know when the timing chain is about to go. i have 95 z28. my mileage is 185,000. the car still cranks right up. and still runs strong. what is the longest you can go with changing it.

 

The chain stretches with use, and eventually stretches enough that it jumps one or more of the timing gerar's theet and the engine runs crappy or not at all. I really don't know how long they last, because a lot depends on how the car is driven. A lot of high RPM operation will cause the chain to stretch more. However, at 185K it is getting close to the engine needing an overhaul, and that would be a good time to replace the chain and timing gears.

 

At 185,000, it just might need changing. Certainly couldn't hurt. Make sure to get Your chain from the dealer, I always use factory timing chains when I keep the original Timing gears. They,re about $25 or so. Remember to buy a new timing cover gasket and seal set when making the change.

 

you can check for slack by removing the distributor cap and manually turning the harmonic balancer with a pull bar. turn it clock wise some then while watching the distributor push it back counterclock wise. if you can move the harmonic balancer ANY without movement of the distributor rotor there is slack in the chain. if the rotor moves with the slightest counterclock wise turn it is still in pretty good shape. Sick

 

thanks for the info. i am getting ready to replace the opti distributor. since i am replacing that i might as replace the timing chain and water pump. is there any thing else i need change.

 

You may want to change the spark plugs and spark plug wires while you are there.