On my 2006 Ford F-150 with the 5.4, there's a loud whining noise, just like a supercharger, sounds like its coming from the serpentine belt and pulleys. I replaced the belt and an idler pulley about 6,000 miles ago, and the problem didn't show itself until recently. I had replaced the belt with a Goodyear gator-back. The sound changes with the RPM's, and can be heard loud at idle and higher RPM's. I've attached some videos, can someone provide input of what it might be? I thought it could be the power steering pump but the noise isn't affected by turning the wheels, just acceleration. Maybe a bad pulley somewhere? I'm not sure
Just replaced all 3 idler pulleys, it's still there! it does it whether the A/C is on or off, So i don't think it's that one. So maybe the alternator? Don't really want to buy a new one considering the one that's on there works just fine.....possibly belt? it's the expensive gatorback that's pretty new....
2006 Ford F-150 Supercrew Lariat
305/55/20 (33's) Terra Grapplers on Dick Cepek DC-2's
Rancho Quicklift's on front, Bilstein 5100's on rear