Engine noise goes away when AC turned on?
 

I have a 2003 Tacoma Double Cab V6 with about 97k on it. I just started experiencing engine noise after warmup. My first take would be an idler pully or fan with a bearing going, but the odd thing to me is if I turn on the AC it immediately goes away. I haven't even popped the hood yet, but anyone have any ideas based on the effect of the AC being turned on? What gets taken out of the picture?

Sound like mayby your ac clutch? Might pop the hood and see where it's coming from.

When I put in my engine and was fitting the ps alt fan pully, I dropped it and bent the lip right on the edge. When running, that lip would hit the belt and it seriously sounded like rod knock. Anyway to make this relevant, when turning the steering, there was more tension on the belt and the noise would go away. Might want to check for dents or wobbles on any pullies and also check for belt tension.

Good Advice...check the easy stuff first.

Also agree on checking the AC clutch.