'87 80 1.8 Heater problem

[Tom Nas]

At 18:19 2-1-02 -0500, Huw Powell wrote:

> > Patient: '87 80 1.8 carb.
> >
> > Symptoms: outside temps just below freezing, engine gets hot (water temp
> > gauge hits 90 C) but heater blows nothing but cold air with knob set to
> > full heat. I get in a traffic jam, temp gauge goes to 100 C (I get slightly
> > worried) and suddenly the heater starts working.
> >
> > I'm thinking sticking thermostat. Any other suggestions?
>
>I'd say the two places to start would be the thermostat (never hurts to
>replace them) and the heater valve - remove the valve and see if it
>really works, or if it is screwed up inside.  Undo one more hose and you
>can flush your heater core.  two or three more and you flush the whole
>system...


Thanks, Huw. I don't suspect the heater valve because I didn't operate it
when the heat stopped, or is that a common failure mode? I thought they
just broke so that the operating mechanism got stuck in one position...

A full flush might be a good idea. The car's overdue for some sort of
maintenance anyway.

Regards, Tom