Hey everyone. Noticed this sound a few times now. If u rev the car up 89 2.8. U get a humming or buzzing sound comming from the engine compartment. Sometimes this sound starts to happen just before u let off the gas. Not sure what it is.

 

Does it have a metallic ticking mixed in with the noise too? It is most likely a bad bearing on one of the belt pulleys. If you have AC, that is typically the most common bearing to go, but it can be any of them, like your water pump, tensioner, etc.

 

im pretty sure its the belt tensioner or the idler pully no biggie

 

Also check the wires in the fan relay connector. My 86 had bare wires there and made a buzzing sound randomly.