alternator knock

[RangerX]

My alternator's been knocking/rattling for a while now. It think it's from getting a little water in it while hosing under the hood. Seems to do it only at idle and just off idle. Plus when it's idling, the noise while come and go, knocking for a minute, then quiet for a minute, then the knock comes back. Any ideas other than replacement? I'm thinking maybe spray some WD or something in there.

 

[beavis195]

Spray some Electrical parts cleaner. I know Home Depot has it. That would be my best bet before a replacement. I don't know about WD40.

 

[jimmiecakes]

WD-40 will likely cause slip ring/brush problems if it gets into the wrong place. It'll leave a film behind that will attract dust and crap......

The front bearing is sealed so there wont be much benefit there. Check to be sure there is nothing caught in the cooling slots in the case and it'd probably be a good idea to be sure that this sound isn't telegraphing from the water pump or some such as well.

Good luck...

 

[Mike 92 XLT]

Mine was doing the exact same thing and it turned out to be a bearing going bad. Had to have it replaced (under warranty though - these rebuilts suck).

peace

Mike