ive had times where heater cores were clogged and the best way to unclog it is to have water flow both ways. flushing water by just spraying water through where the tstat is wont do that and what you have to do is take the hoses off the neck of the heater core very carefully or just take the hoses off the alternator bracket. dont blast water, just spray it to get a flow coming and to where the same amount of pressure comes out of both sides. this message is probably too late lol but at least ull know for the future.
