Forum Discussion

Explorer

May 31, 2014

Any tricks, strange noise under hood/ which pulley?

Need help finding out which pulley or bearing is on its way of going out on 5.4 ford engine. Beginning to make a small grinding noise and would rather fix now in driveway instead of on the road. Problem is I can't figure out where the noise is coming from.

I've loosened the belt and wiggled each pulley, no excessive play in any of them.

I've put a screw driver again each pulley, no vibration feeling up screw driver.

Any other ideas I could use to figure this out?

2003 5.4 I'm pretty sure the pulleys are:
Alt, pulley tensioner, water pump, A/C, etc

13 Replies

Flyfasteddie
Explorer
May 31, 2014
I'd take the belt off and individually spin the pulleys. The culprit should be obvious. I would lean toward any idler or tensioning pulleys as being the problem.
Grandpere
Explorer
May 31, 2014
Very carefully use a Stethoscope, it will pick up sound very well from each pully. The grinding noise could also be a water pump, alternator, power steering, etc. Does the noise change when you turn on the AC? could be the idler pulley.
westend
Explorer
May 31, 2014
My guess would be the serpentine belt tensioner. Mine was noisy so when I changed belts, I changed the tensioner. They are only a few bucks.