Buzzing sound right side of engine compartment near belts

[Mike-Laval]

Hi There, This is my first thread. Great info on this site but I haven't found one covering my issue.

I start the engine and it runs smooth. I then I rev it a few times and the buzzing starts. It's on the right side close to the belts.

It's not the belts or the tensioner because if I rev the engine the buzzing is constant. If I turn the engine off and restart it the buzzing is gone until I rev it again.

Anyone have a clue as to what it might be?
Modified by Mike-Laval at 2:18 PM 2/11/2009

[jetroy240]

Probably a cracked tensioner bracket or cracked exhaust gusset brackets. Just remove the tensioner pulley & inspect the bracket . If it's ok, could be a timing chain noise, worn guides.
Modified by jetroy240 at 7:59 PM 2/7/2009

[Mike-Laval]

Like I mentioned in the first post, I don't suspect it is related to belts because as the engine turns faster the buzz would change pitch but it doesn't. It stays constant like a buzzer or a pump or a compressor.

[Mike-Laval]

Found a post on page 11 that talks about motor mount noise, I'll try to disconnect the mount to see if the noise stops.

Does anyone know were the connector is for the right side (pulley) motor mount, might save me some time.

By the way I noticed I didn't mention it's a 2004 MO SL AWD.

Mike

[jetroy240]

The motor mounts that is electrically operated is located at front & rear, between engine & transmission, one is near radiator , the rear is near the firewall & steering rack. You can visually look at the mounts & trace the wiring to the brown connectors. Just disconnect it one at a time & see if the noise go away. The front is easy to access its just near the transmission dipstick. Good luck on the rear. Time to replace it if it's really noisy & leaking.

[Mike-Laval]

Just back from the dealer. Seems the buzzing was from the regulator valve in the oil pump !! Hard to beleave it was making such a loud noise.

Well now I'm happy again. No charge!! I din't think that was possible these days at 90$/hr!!

Thanks for all your inputs.