Buzzing/razzing sound from the passenger side of the engine? - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

WindsorFarmer · 03-05-2011, 13:28

5.4L 2002 E350. It started awhile back, maybe November. I also noticed a drop in performance - about 2-3 MPG drop. I took off the inside covers and started it up so I could get a better bearing of where is is coming from and it's near the top of the engine, around the valve cover. You can only hear the nose when it idles, press the gas and it's either overcome by the other noises or perhaps it stops.

To me, it sounds almost exactly like the sound I hear from my '91 Dodge 3.3L's PCV valve which seems to have gone bad.

Thanks in advance!

Mike

**jwko** · 03-08-2011, 04:02

Is it a whistling sound?

Quote:

Article No.
02-10-8

05/27/02
^ DRIVEABILITY - 5.4L 2V - IDLE-AIR BYPASS FLOW INDUCED WHISTLE

^ ENGINE - 5.4L 2V - IDLE-AIR BYPASS FLOW INDUCED WHISTLE

^ NOISE - IDLE-AIR BYPASS FLOW INDUCED WHISTLE - VEHICLES EQUIPPED WITH 5.4L 2V
ENGINE ONLY

FORD:
1999-2002 E SERIES, EXPEDITION, F-150, SUPER DUTY F SERIES

ISSUE

Some vehicles equipped with the 5.4L 2V engine may exhibit a "whistling" noise from the formed nylon tube in the idle-air bypass flow circuit. This may be caused by air flow passing through the sharp bend radius of the original tube assembly.

ACTION

Remove and replace formed nylon tube with the Nipple And Hose Assembly 2L1Z-9W548-AA. This action will correct the sharp bend in the tube.