On Wed, 2011-06-15 at 20:36 -0600, YES NOPE9 wrote:
> gradually overheats on long drive
> no coolant is missing
> fan belt is quiet ... does not appear to be slipping
> turning on interior heater with fan brings temp down
> ( i have only seen water pumps fail by leaking and screeching )
>=20
> What might it be ?   How can I test ?
> 99guspuppet

The fact that turning on the heater solves the issues points to the
radiator part of the "loop". Your radiator might be clogged, either
internally, or externally. It could also be piping/hoses going to the
rad.

If it looks good on the outside, dry draining the rad (most have a drain
plug near the bottom, otherwise just remove the bottom hose) and having
a look with a flashlight to see if there is an abnormal amount of
deposits in it.

TTYL

--=20
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