Time Chain....?

Not sure on the timing chain service interval is on that engine. Pretty sure that it is an interference engine - one with minimal piston to valve clearance. If you get a slip in the timing chain (due to wear and loose clearance), the piston will likely crash a valve... major headache. A valve tap is usually caused by a bad lifter. AFIK that engine uses a hydraulic lash adjuster which may be getting spongy and in need of replacement. Tap can also be caused by a sticking valve stem.

Thanks for the tips, I will be opening it up this weekend I hope...See if I can find anything.

Still if anyone know the suggested changed interval, I would like to know...

Thanks.

There is no service interval. The chain is supposed to last the life of the engine. If it does need to be replaced it will make lots of clattering noise alerting you to impending doom. Oppie is correct in that it is and interference engine. If the chain snaps it'll bend the valves.

Proper oil changes should prevent that, among other things...

I have a Saturn SW2 1997, I had a click noise at 118,000 km sound like a valve problem. try this: unplug a spark plug (there is no danger) on piston #1 listen for the noise, if the noise doesn't change replug #1 and do the same for #2 etc, if you find one piston where the noise reduce or desepear it's the pin that hold the piston to the arm that is loose (sorry my english I am french CA) I had that problem and I remove the engine from the car and send it to a engine refit center (the oil consumption problem was solved at the same time). Hope it's not that problem for your car. the computer was giving me some code also.

You dont ever remove the spark plug wire unless you "ground" it. Otherwise you risk damaging the coil(s). The other way of doing this would be to disconnect a Fuel injectors one at a time. Not really possible with 60deg motors like the 3.0L however but thats why GM dealerships have the advantage with their Tech II scantools that can stop injectors from pulsing. But yeah cutting off a piston one at a time can pin down a problem.

Think those chains are steel.

Well At you great suprise it's the saturn mechanic itself in montreal that did this, my friend is the service director at saturn and he ask one of his best mechanic to have a look at my car and that's what he did, and my neighbour and my oncle that are both mecanics and they did it with no problem. I am not saying that there is no risk, but if I look at what they did it seem's like the risk is very low. :)

Speaking as an electrical engineer and fair mechanic, removing the wire from a functioning plug does cause excessive high voltage which can damage the spark coil and more importantly, kill the transistor that drives the coil. Since the transistor is likely in the ECU, that can be a big oops! This is not to say that I have never removed a plug wire from a running engine either, it is just good to know what the potential damage might be. The coil drive transistor is actually pretty well protected but having a plug wire disconnected does cause abnormal stress on the components... and stuff happens.

You can definitly hurt a coil by pulling a plug wire and not grounding it. But as long as you keep the wire near the head so the spark jumps into the head, you should be ok.

Also remember that the Saturn uses a waste spark ignition system. If you remove a wire and don't ground it you will actually have two cylinders misfiring.

Thats correct. There are 2 coils. When a coil fires it simply completes the circuit between the 2 posts. One cylinder will be on compression stroke, the other will be on exhaust.

cylinders

completes the

What I've done in situations like this is to connect a spark plug to the disconnected wire and then ground out that spark plug.

Ken

Yeah. I don't think I've ever seen a busted chain either. Usually the chain stretches with age and the tensioner stops tightening it up leaving slack in it, which lets it skip a tooth. It is interesting how much difference one tooth can make.

Engine timing is such a precise thing. This is why I will never trust a "belt" for keeping it in time.

how do you know if a car has a belt or a chain? i mean like on the new cars.

Why not? Timing belts usually have a Kevlar core and are stronger than steel belts.

I usually do a google search if its an engine I'm not familiar with. If you can look at a owners manual it will say in the maintinance portion if a "timing belt" is due for service.