2004 honda civic overheating
I have a 2004 Honda civic. My heater only works when I
drive about 40 mph or more, but not always. Sometimes
even while moving it will blow cold air. It blows cold
air at stop lights or when going slow. When cold air is blowing temperature gage starts going up and engine starts overheating. I floor the gas all of a sudden hot air could start blowing and then temperature gage show engine temperature goes to normal.
I replaced the thermostat and it seemed to work
Okay for a month, then started this nonsense again.
I checked the head gasket and its fine.
And at times it will be totally normal its kind of a random thing that keeps happening every week... a Honda tech of 25 years said my car is totally fine and there's nothing wrong with it, then it will do it again the next day....
Anything else I can try?
Check the water pump,
Make sure you always have good amount of coolant in the radiator and make sure you use the 50/50 blend. I had the same problem and switched out my thermostat, cooling fan switch, cooling fan relay and almost the water pump. I found that I had a very thin crack on the hose that runs from the reservoir to the radiator. I swapped it out and now it works fine.
Also check your hoses. If they are too flimsy (when warm) change them.
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