heater core problems

[94Z28]

hey all,

I just picked up an abused '94 Z28 and with some tender love and care got it to look like a Z28 should. However, there still is a one major problem; the car just doesn't heat up. The heater puts out maybe 75 degree air but no warmer. This is an ever growing problem seeing as I live in Michigan and it is getting cold. Can anyone help me out with advice? I was thinking a coolant system flush including the heater core but am willing to heed other advice. Thanks and let me know.

[89IROC&RS]

well, the first think i would look at is your temp guage, if the previous owner put in a 160 degree thermostat, then the coolant going throught the heater core is not at the normal temp, and heating ability suffers. also, are you sure that your heater control unit, (also the AC controls) is functioning properly, if you arent moving the vent doors all the way to the proper location, then you are mixing hot and cold air, giving you luke warm air. i wouldnt reccomend the flush, unless the radiaor needs it, it would be a waist of money, instead, pull the dash, (sorry, i know its not fun) and look at the heater its self, see if it is over grown with mold, or if there is some other blockage on it. then look in your heater vents, very often things get dropped in there and block the heat. also, the heater on this car, if its like my third gen, doesnt blow out of the passenger vents, unless its on MAX AC, when you have the heater on, it blows out of the front window defroster vents. so see if its coming out of those vents hot. those are the most probable things i can think of off the top of my head. good luck

[coindex]

Signs of a heater core problem:

rad fluid leaks on your passenger side
fogging of windows (slime can create when u wipe window)
cool air blows when warm is selected on temp. selector