Uh Oh! Rattling sound from Water Pump or Crank....or?????

[Orangecrush]

Man oh man....I haven't started or driven my bronco in maybe 4 or 6 months. I started it up and hear a pretty loud rhythmic "rattling" sound. I am pretty damn sure it's coming from the middle front of the motor. I do not think it's the power steering or a/c compressor or alternator. It seems to be coming from the dead center......the water pump or crank area. Pully? Harmonic Balancer, Water Pump bearing (not leaking ANY water at all)? Crank Bearing (please god no)? Something else??

It goes away if I run it for 5 or 8 minutes.

Please listen to the video on youtube. Does anyone have any other ideas what this is?

Thanks MUCH MUCH in advance!! Oh yea, it's a 351W (if that matters for some reason).

http://www.youtube.com/watch?v=P_S9rvVtoBM

 

[76Explorer]

It sounds like a bearing to me. remove the belts and check the fan, a/c, and alternator for play. I have ruined a new alternator before by over tightening the belt.

 

[Bully Bob]

Hay crush..where ya been..?

Yep... bearing would be my 1st guess.. that's not an internal eng. noise like rod/crank/lifter...so., not to worry.

However., as an initial test... rub some paraffin wax., or candle wax on the belts.., one at a time (so as to isolate the bad one) (do this W/eng. off.!)

I've heard some brands of belts make simular noises that would scare ya bug-eyed., espec. aft. sitting that long.

If NOT the belt(s) then it's a bearing in W/pump., alt., A/C pump.

H.F. sells those Dr. ear piece things that can isolate a noise real easy by touching the component with the rod end.

They work.., & cheap..!!

ALSO., I've heard A/C comp. clutches make a simular racket.

------------- I don't think a W/pump bearing rattle would go away but, anything is poss.

With belt off., or loose... see if you can wiggle/wobble the fan & see the W/pump shaft moves.