A Humming noise on 2004 Camry, I had a valve cover leak and replaced that along with new serpentine belt and I thought the nosie was the factory Alternator and replaced it. The noise came back after 2 days. I'm thinking maybe the idler pully itself?!
Help!
All this while at idle and as fuel is put to it does get louder. 230,000 miles.

 

Use a section of rubber hose as stethoscope to locate the area of the noise.

 

👍 we did do that and it was super loud at the Alternator.

 

V6 or 4 cylinder engine?

 

Sorry I should of stated that 4 cylinder in my first thread

 

It's either the alt, the idler, the belt or perhaps a pulley issue?

Are you doing the repairs yourself?

Did you replace the alt with a rebuilt or new unit? Some rebuilt's can be bad right out of the box.