Loud Ringing noise at idle ?? (With video)
 

Hi all- any help on this would be hugely appreciated!

LINK TO VIDEO OF NOISE HERE:
The truck is a new to me '88 toyota pickup with 22RE, A/T 2wd. 90k miles, runs great. The issue I’m having is a hard to identify ringing noise coming from the front end of the engine. It goes away immediately when I give the truck any amount of gas.

It is at its loudest when I am stopped, in gear, and with foot on the brake. It will occasionally ring when in Park as well.

I had my alternator replaced the day I bought the truck. It has made the noise ever since, but unfortunately I didn’t drive the truck long enough before the alternator replacement to know if it made the noise prior. That shop replaced the alternator belt and one other belt down there, possibly the fan belt.

The noise will be less loud and at times not even happen once the vehicle is very warm and/or has been driven on long trips consecutive days. I didn’t drive the truck for the last couple days and the noise was very loud today.

Could this noise be a pulley bearing? I took it back to the shop that did the alt and they listened and used their stethoscope and said it seemed to be coming loudest from a bolt on the timing cover but that they wouldn’t worry about it.

It is just confusing to me that it goes away when engine is revved. I guess it must be that when in Drive rpms are at their lowest causing something to vibrate in such a way that it rings like that? In the video you can hear it really clearly. Has anyone ever came across this sort of noise?

Thanks again,
Ben