I have this light noise that only comes up after I restart the engine when its warm. This is how it goes.

Engine cold---> start the car---> no engine noise everything okay---> let the car warm up for a bit---> turn off the car for 10 minutes----> start the engine---> noise comes up for a split second like scratching rattling noise.

I am pretty sure there is something wrong here because I have rabbit ears but the noise goes away so quick I cant hear where its coming from.

As explained above the noise never appears after a cold start only after semi warm start.

IT sounds like a mix between internal engine rattle (small rattle) and scratching noise.

I did a compression check and all the little maintenance things and everything turned out to be well.

Any thoughts?

 

Could it be an accesory you think? Like a bearing starting to go out in the air pump, alternator. Maybe its just the begginning stages and when things are warm the tolerances are closer. It could be the sound of your belt slipping/dragging over a accesory that is starting to seize? With the info these are the first things that come to my mind. If it were something mechanically with the engine, typically you would think of lubrication or lack there of, and typically that would be more present after first start up when things are cold, not the other way around. Makes me think its not the engine. Compression was good anyway.

 

Yes its weird I built few engines and I truly never heard of such noise before. A belt slipping sound is more like squeaky noise... this is more like metal.

The car has 92K on it, engine was never messed with everything looks intact!!!

 

[QUOTE=az3ar,Apr 23 2009, 08:10 AM] Yes its weird I built few engines and I truly never heard of such noise before.

 

Its not it just comes and goes within a second and "only " when its warm

 

I have the same sound, happens more often when its cold though. I think it might be a heat shield rattling. Sounds real metallic, rattlely, and scratchy.

 

^^^ I bet it is. Mine was a long time ago, I removed the devider, also I noticed a crack in the manny cover under one of the mounting bolts.

 

I foudn the answer


Bad tensioner characteristics:

Varys with engine speed.

Can come and go at will. USUALLY does it at first start in the AM, and sometimes after a hot start after sitting for 10-15 minutes. I have also seen engines that do it constantly.

It is very loud. It's as fast as a ratchet, if you were to spin it around in your hand.

If you can count the individual clicks at idle, it's not the tensioner. Tensioner clicks are about 20-25 per second. as opposed to valve train noise at idle, about 5-7 times per second.

 

cracked exhaust manifold heat shield it what is sounds like to me mine did same thing.

 

It's either the timing chain tensioner (TCT) or the starter. See starter sticking.. This topic comes up at least once a week so many many threads on exactly what you are describing already. But it is 1 of the too. I have the same noise. I believe mine is the starter sticking.