Rep Power: 0

Hello,

I am an owner of a 2001 Honda civic ex. I have been reading around and I can not seem to find a right answer at all. I am not a car expert so I will need as much help as I can get. The problem is my heat is not working. A/C works perfectly fine. Story is, it wasn't working until I took it to the shop last year and switched thermostats with a full coolant flush. It worked after that but after a few months it died. A few months after it died it decided to work again oddly but then after another few months after that it has died again and it does not work. It blows heat but very little heat (a little cooler than room temp) and once I turn the defroster on it only blows cold air.

I was reading the forums and they said it could be my thermostat but I switched that last year, but it could be a faulty new one (done at the shop) and I also got a coolant flush at the same time. Second, they said it could have been a blockage with the cabin air filter... opened that and there was no filter.... could it have been clogged by dust, leaves, and other things? Third is the heat fuse.... I switched it with my power windows fuse and it seems to be working just fine. Could it be the heater core? I have no idea what is wrong and winter is comming. I need help! any advices will help! thank you so much guys!

 
Rep Power: 185

Unfortunately this sounds like a blown head gasket. If your cooling system has been properly bled, you need to search the forums on blown head gaskets. It will give your all kinds of information. I'm sure that's not what you wanted to hear, but these 7th's gens are notorious for blowing head gaskets.

 
Rep Power: 517

Absolutely.
Spend the extra $6 for a factory stat this time if you decide you need one.

1) Does the engine get warm enough to give heat?
2) Does hot coolant flow through the heater core?
3) Does the heater core radiate that heat effectively?

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Does the engine actually warm to the correct operating temperature (180*-210*F)?

How hot are the heater hoses at this time?

Does the temperature actuator work, does it move the blend door when you change the dial on the dash? Does the water valve work at the same time?

 
Rep Power: 0

Thanks! I will look more into it and I would actually love to hear all the information you can give me or possibly help me find a link so I can get it fixed. Is there a video or step by step posting on how to replace a 2001 civic head gasket? How long does it usually take? I'm guessing if I do it - it's going to take a few days?

 
Rep Power: 0

The engine gets warm for sure because the temp gauge in the dash starts from the bottom and slowly rises just below half way. How would I check for the flow of the coolant and how the heater core radiate that heat effectively? The coolant hose from the radiator is hot - hot enough where you touch it and you pull your hand away but probably won't burn you and it is the one that is in front of the engine connecting to the radiator cap.

 
Rep Power: 307

Check your coolant level in radiator when engine is cold.

You can see the valve that allows coolant to heater core on the upper firewall near center in engine bay (blue cable) make sure it is moving as it should.

 
Rep Power: 517

Grab both heater hoses at the firewall, feel the temperatures. If both are too hot to hold, then there is probably flow. If one is much cooler than the other, then the heat has been removed by the time it got to the end or there is insufficient flow.






When the typical 7th gen blown head gasket causes a lack of heater output, it's because of an air pocket trapped in the heater system..... Revving up the engine usually brings some heat back (increases liquid circulation), until you let the engine slow down again.

 
Rep Power: 0

i bet that there is air in the system. do you get hotter air if your getting on the highway on ramp or rev your motor up? checking the heater hoses will tell you if there is flow also. if the hoses are both hot and there is no temp difference when reving the motor then the blend doors inside the heater box aren't working.