[TR] One last question

[Randall]

> What sorts of symptons can a defective thermostat give?

Fairly easy test, without disassembling anything: Raise the hood, start the
engine from cold.  Let it idle until the temp gauge gets near where the
Tstat should open.  Feel the radiator upper tank and core, it should still
be noticeably colder than the thermostat housing.  (Be careful when you feel
the Tstat housing, it's hot while the radiator isn't.)  Continue to let it
idle until the upper tank suddenly gets quite hot, same as the Tstat
housing.  If the temp gauge reading is reasonably close to the Tstat rating,
then it is probably working fine.

Although not a 100% test, I've never seen a bad thermostat that would pass
it.

If the temperature creeps up over 20 miles, I tend to doubt that it is the
thermostat.  If the tstat is stuck closed, it will overheat much quicker
than that.

FWIW, I've had that exact symptom twice now.  Both times, after checking
everything else, it turned out to be a bad radiator.  Now with the new
radiator core and the electric fan, I never see 200F even in 100+ ambient
stop and go traffic.

-- Randall