In a message dated 98-05-21 14:49:31 EDT, you write:

> Why is this?

The heater core under your dash and if you have a rear heater, under your rear
seat, is essentially a radiator like the one mounted behind the front grill of
the bus. Therefore turning on the heat runs the engine coolant through these
"extra radiators" transfering the heat from the coolant to the passenger
compartment. Since the heat is being taken from the coolant by blowing air
through these "radiators" the engine temp will drop slightly or dramatically,
depending on conditions.

This is a normal condition. Also helpful if your automobile is overheating due
to stressful conditions like hill climbing-- crank on the heater full blast
and help that coolant and therefore your engine get cool. You may sweat a bit.
But it beats overheating.

I should add, if your engine is continually running too hot and needs to be
regulated by turning on the heater something is amiss. And this situation
should be checked out.

Best O-
Jeff
83.5 Westy