My engine makes a whirring noise from the front cover area, but only when the engine is hot. I have to run it at least 30 minutes before it starts. By the time I get home from my hour drive home, it'* whirring/howling loud enough to hear while sitting in the car with the passenger side window down. To isolate the noise, I removed the serpentine belt briefly, and it still made the noise. It'* right from the harmonic balancer area, and kinda sounds like an alternator with bad bearings. I know the oil pump is in the front cover, and that'* my first guess. Behind that, of course, is the timing chain. I wonder why if it IS the oil pump that it only does it when hot? Supposing that it is the oil pump, how would I diagnose that to be sure? I don't have any oil pressure issues. I recall that these engines don't have oil pump issues very often. Hmmmmm...

Which car?

Sorry! It'* the '97 SE. I don't know that it'* related, but I should mention that I bought the car with a failed UIM and ultimately had a cracked head. It didn't do this until several hundred miles after the repair. I know it'* NOT a knock, as might come from rod or main bearings. The noise seems mostly constant in pitch whether at idle or when revved.

Get a mechanic'* stethoscope and start poking around. I doubt it'* the oil pump. they seldom fail. checked your power steering fluid lately?

Alternator or AC compressor would be my guess.

Those would have been mine too, except that the noise continued with the belt off! So that takes the p/*, alternator, and a/c compressor out of the picture.

Hmmm.

A timing chain would be the most likely candidate here, but it seems that would be noisy all the time, although perhaps it only starts grumbling when the oil heats up.

TTT...

UPDATE: Man, was I wrong. I put the car on ramps to hear the noise better, and could instantly tell that it was NOT coming from the front of the engine, but from the torque converter area. I guess the top two causes would be either the converter itself, or the pump.

Anyone want to buy a nice '97 SE that sounds like a 747 after about 30 minutes of driving?

Uh oh.

Not to be insulting and kinda basic, but have you checked the fluid? changed the filter lately?

I checked and topped off the fluid when I installed a trans cooler about a month ago. The fluid level was fine before I started. There are no leaks. Having been rebuilt about 30k ago, I was just starting to think about doing a fluid/filter change anyway. I guess I can do that, and check for any particles in the pan. :o