I posted a while back looking for help diagnosing an engine squeel, and I still haven't been able to figure it out.
Symptoms:
Metalic squeel at startup, and on revs for maybe the first 2-3 minutes that the car is running. Also occassionally under zero throttle coasting conditions in the 2-3000 rpm range (i.e. going downhill in gear). Not nearly as loud in off throttle coasting. It is definitely a metal to metal sound, that changes pitch with engine speed. It seems to be effected by temp, as it doesn't do it nearly as bad when the outside temp is high. It is definitely internal to the engine, as I've pulled the serpentine belt completely, and it still does it. There has been NO loss of performance since this started.

Things that I've checked:
Serpentine belt, pulled competely and it still does it.
Balancer, doesn't have any play.
Oil, no major amount of metal/shavings over the last few oil changes since it's been doing this.
Plugs, have been changed and are seated good.
Exhaust manifolds, gasket has been changed on one side that had a slight leak, all bolts have been checked.

I've had it in to my mechanic and he's stumped as well. He's checked it and says it seems to be coming from the front passenger side exhaust manifold area, but he can't find anything that's causing it. He's had the valve covers off and didn't find anything there. His thought is that it might be slack in the timing chain, causing it to rub slightly on the cover until it warms up, expands a little and then eliminates enough of the slack so that it doesn't rub.

Any ideas? I really don't want to go digging into the engine for with no clear idea of what's causing the problem, but I also don't want to let it go and have it turn into a big problem later on. I'd be much more worried about it, but like I said before I've had no metal/shavings in the oil and have had no loss of performance?

 

Flywheel rubbing the inspection cover?

Starter staying engaged?

Take the cover off and put it on ramps to view it while it's running.

 

Did ya cut the filter open to check for metal?

Could be a gaulded piston,a bearing including cam bearings if ya did a cam.

 

I'm pretty sure the mechanic checked the flywheel (although I can't remember for sure, I'll ask him Monday). Haven't checked the starter.

No, I haven't cut into the filter, but I would have expected at least some particles on the magnetic drain plug if there were going to be any particles. Haven't done a cam.

 

Cut the filter open and see.