[geeks] OT: Car question

[Tom Borton]

Not there ever is an off-topic on here, but I have a question for all the car
geeks.  I noticed today that my temperature gauge ('95 Ford Windstar - insert
manliness joke here) would drift quickly down from where it normally runs and
then climb slowly back up.  Other items of note:

1.	Drifting down always seemed to occur faster than the return.
2.	It was not a steady drift down and a steady climb back up, and it wasn't
always climbing back up all the way to normal before it would drift again.
3.	It never reached higher than normal.
4.	It did not drift down when stopped, only when moving.
5.	The heater was supply a consistent temperature even when the gauge was at
the bottom of the cycle.
6.	The engine was not making strange or unusual noises.
7.	No magic smoke was escaping, and no other signs of leakage.
8.	I haven't checked the coolant level yet because I'm waiting for it to cool
down.

Any suggestions about what might be happening?  I have a couple of ideas, but
my car knowledge is next to zero.

Thanks,
Tom

"The most exciting phrase to hear in science, the one that
heralds new discoveries, is not 'Eureka!' (I've found it!),
but 'That's funny...'" -Isaac Asimov