Heating AC and Engine Cooling
Chevy S-10
Heater Cores and Blower Fans
Car Heaters

Why does a 2000 S10 heater just blow cold air after repairing a leak with a heater sealer?


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2011-09-13 23:43:14
2011-09-13 23:43:14

Thermostat stuck open. Drain and flush the system, replace the thermostat, fix the leak properly, and reinstall a 50/50 mix of antifreeze and distilled water.Also check rad cap as it may not be holding the pressure. Heater core may also need flushing if you put a sealer into the system

Answerit also may have plugged up your heater core (which is where the heat from radiator fluid is transfered to the air to make it hot) the best bet is to never ever use a sealant in your cooling system unless it is a dire emergency, cause it will always cost you more down the road. AnswerIf you run the engine for 15 minutes or so, grab the heater hose going to the heater core at the firewall, it should be hot and the one coming out should also be hot. If one is hot and one is not, then that's the spot. If they are both cold, then coolant is not getting to the heater core. Never use the sealant, it doesn't know the difference between an exterior leak and an interior passageway.

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