Honda and Acura Car Forums banner

99 Cvic doesn't blow hot air

6K views 4 replies 5 participants last post by  cudaeh 
#1 ·
99 Civic HX with ~218k. Blows hot during the summer, but just barely warm in the winter. Temp gauge works, one of the guys at Good Year says the heater core is full of coolant. I don't want to go through another winter without heat because a) it kills my gas mileage when it's cold out and b) commuting an hour without heat sucks.

I really don't want to replace the heater core myself, I'd rather take it in. SO here's my main focus at the moment: What can I easily check before going straight for the heater core repair? I've heard thermostat, but it seems like if that were the cause my temperature gauge wouldn't work either? someone correct me if I'm wrong - I'd love it if that's all that was wrong.

Thanks in advance for any input!
 
#2 ·
did you check the thermostat ? and no your temp gauge still works with bad thermostat. the thermostat doesn't control the temp gauge like you think. the thermostats job is to regulate and it sounds like your thermostat is stuck open. they're like $15 and 20 minutes to replace.
 
#5 ·
agree with every thing that has been said.
order of priority in my mind would be
#1 check that the heater valve by the firewall is working (have some one in the car flip the heater lever and watch to see its actuating in the engine compartment
#2 check the thermostat (there is a test for it oulined in the service manual you basically just need a pot of boiling water and a thermometer: however once you have it out you already need to buy coolent and a new seal so might as well pay the little extra and replace it)
#3 flush the heater core. take the two hoses comming from the firewall off at the engine but leave them connected at the firewall. Make sure the heater valve is open. Using your garden hose force a bunch of water thru one of the two hoses (basically hold running water up to the heater hose and clamp it with your hand, dosent need to be more fancy than that). After about a minute of forcing water thru that hose and watching it come out the other (you should see the water comming out of the other hose from the heater core) switch and run the water in the opposite direction for about a minute. Cycle between hoses a few times to make sure you have flushed out as much as you can.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top