Phigment

Please watch the video and help me diagnose the engine noise in my 03 F150 4.6L V8. Is it the fan clutch?

Engine noise diagnosis - YouTube

JCR 56

Does it do it with the belt off? If not it is one of the FEAD components, just have to find which one, if it still does it, then it's in the engine.

Phigment

I took the belt off this weekend and the noise is gone. Now how do I identify the culprit? My guess is either the fan clutch or the bearing on the belt tensioner.

How much should the fan spin by hand without the belt on?

Jbrew

I heard pulley bearings make some peculiar noises in the past and that may be the problem.

If I were to guess, that sounds like a bad water pump impeller.

MCpllabelle

Yup...I think thats right.

crew man

Sounds like the belt tensioner to me, more so the spring inside the tensioner then the pulley. With the belt off check all the pulleys by hand (spin them) check the idler as well. Good luck

Phigment

Right about the pulley bearing or water pump impeller?

Phigment

Right you were! Replaced the belt tensioner assembly in about a half hour and the noise is gone! Thanks everyone for the help.