Odd noise, now gone !?

[kiwi_outdoors]

while on vacation, one cold morning there came from under the hood at fast idle a noise which I traced using a "mechanics ears" (breaker bar in one ear, other end on item of interest) - and convinced myself and wife that one or more bearings on the alternator had gone bad. (water pump is new, belt idlers pulley are new). This continuned for a couple of days and then we relocated to an RV park in town and procured a new alternator. The next morning, the sound was gone!!

We have no explanation for this. It's still fine.

 

[turblediesel]

Was there a full moon? Some werewolves like to wrench.

 

[Paul Dalby]

while on vacation, one cold morning there came from under the hood at fast idle a noise which I traced using a "mechanics ears" (breaker bar in one ear, other end on item of interest) - and convinced myself and wife that one or more bearings on the alternator had gone bad. (water pump is new, belt idlers pulley are new). This continuned for a couple of days and then we relocated to an RV park in town and procured a new alternator. The next morning, the sound was gone!!

We have no explanation for this. It's still fine.

Alternator clutch? If I remember right, mine is noisy when the clutch engages the alternator, normally switches on every minute or so and lasts for about 10 seconds - but I don't know if mine is normal or not - it's just always done it since I've had it.
Maybe your battery charge was low on the cold morning, engaging the alternator clutch more, but after a drive the full charge was restored?

 

[kiwi_outdoors]

Alternator clutch? If I remember right, mine is noisy when the clutch engages the alternator, normally switches on every minute or so and lasts for about 10 seconds - but I don't know if mine is normal or not - it's just always done it since I've had it.
Maybe your battery charge was low on the cold morning, engaging the alternator clutch more, but after a drive the full charge was restored?

There is no clutch on the alternator in my Liberty (only on the AC compressor).

 

[turblediesel]

There is no clutch on the alternator in my Liberty (only on the AC compressor).

The alternator clutch isn't electrically operated like the air conditioning or viscous heater. It's a much smaller diameter mechanical clutch made by Liten. I think it decouples the alernator to control the alternator's speed. Rust dust near the alternator pulley hub is a bad sign.

Maybe this wizardry isn't on the export version.