Hi;

Okay. Thanks for the response.

Rich

 

Ticking on cold start that goes away is usually a loose or bed timing chain.

 

Hello;
Thanks for the suggestion. I considered the timing chain, but at 85,000 miles didn't think it likely. Also, my experience in days of yore of a stretched timing chain is that if while idling one races the engine (in neutral) and then lets it revert to idle it would rattle as the engine slows. This does not happen in this instance. I guess an additional consideration is the chain tensioner. Didn't have tensioners back in the day. Can't speak to that as having no real experience there except I would expect the tensioner to compensate. The car runs fine. I would expect some performance issues if the chain were stretched very much as cam timing would change.
Can you explain why it would only rattle initially and not all the time? If it's loose it should be loose all the time I would think. Still confused....

 

Not really a big job at all. You pull the valve cover and check that the chain is tight. There should be no looseness at all. If it's loose, then you can take steps to ensure that you don't become the proud owner of a boat anchor.

 

That's likely just tappet noise.

 

Very easy to remove the valve cover and use eyes to see if there is any slack between the sprockets. While you are doing that look at the air box bracket, they break and rattle. And look at the flex pipe.
I might think tappets if you had over 200,000 miles and never changed the oil.

The chain guides are plastic in modern cars. I don't know the mechanism for the symptom, just that over the last 13 years it is true.

Then look at the wheel house linings and the bumper covers.

One person had us going nuts for 2 weeks then found the plastic bag hanging under the car.

 

actually the Ecotec has solid lifters and roller rocker arms

 

Hello All;

Thanks for the interest and suggestions. I will certainly investigate the reasonable ones. Easy to check the chain when I replace the plugs although I intend to replace the chain after one hundred thousand miles as part of preventive maintenance.
As an aside, I intend to get an OEM chain. Should the sprockets be replaced too? Is it typical for the sprockets to wear significantly? I notice some chain kits include sprockets. I do understand the wisdom of replacing while having it apart, but this is a low budget operation. Also, is the chain directional? I doubt it.
I have discovered an intermediate solution for the clicking sound. Turn the radio on.
Thanks again.

Rich

 

Hydraulic lifters can cause valve train noise until they pump up. I can’t say I fully understand when and why this happens though. I understand there are aftermarket lifters for the Ecotecs that are more likely to do this as a trade-off for better high-RPM performance.

 

Chain is not directional, no the sprockets don’t usually wear that much . Chain kit without sprockets is available from Cloyes 9-4201SX and 9-4202SX, they are the OEM supplier. I strongly recommend installing a front guide upper replacement bolt.