01-16-2011, 11:59 AM
If it's low on water the heater core will suffer. At higher rpm there will be enough water to circulate to the heater core but not at idle. Still enough to keep the engine cool but not enough to provide you with the heat you want. Maybe just a low water level. The tstat should have a stamp on it to indicate the opening temp.
Tim
Tim
74 Bronco Ranger halfcab w/toys: lockers f&r, wristed arm, C4, D20, hyd assist steering, 37"MTRs, warm 302. Capability, that's what I'm talkin' bout.