ps56k wrote:

> 2001 Grand Cherokee - 102k -
> Had the oil sensor replaced - now reading more normal..
> Could it have just been dirty contacts after last oil change ?

Dirty/corroded contacts is probably the first place, especially on older
vehicles, but the cost of the new sender is cheap enough and one that old is
a likely candidate to leak amyway.

> They also noticed the fan blade wobbled on shaft,
> and replaced the fan clutch...
> Wonder what that is - how it works; must be a mechanical rotation limiter
> ? Also - how do you reach & replace that,
> as is doesn't look like the protection shroud was removed ?

The clutch is a fluid type. Basically, the little coil on the outside is a
temperature sensor that controls the flow of the oil inside so that the
hotter the sensor gets the less oil is allowed to bypass which puts more to
turning the fan. If you watch as the engine is turned off, you should see
the fan continue to rotate for a few seconds.

The fan is mounted by 4 small nuts on studs. PITA to get to, hard as heck
to keep the whole thing from rotating as you try to loosen them but ANY
side-play or wobble is reason to change. I've seen a few where the owner
ignored a loose one only to have the fan eat the radiator...

Depending on the exact vehicle, you may get it on/off with the shroud in
place but to me it takes less time to just remove it to change the clutch.

--
Will Honea