Can anti-freeze mixture affect engine temperature for Honda Civics?

About a year and a half ago I changed the thermostat on my 93 Honda Civic. I bought the thermostat from NAPA auto parts as an aftermarket thermostat and simply replaced the old one per the Haynes repair manual.



Ever since then, the engine temperature has been great in the summer time and rarely gets halfway up the "normal" temperature indicator (it usually runs about 1/3 of the way up in the normal temperature range). However, when the temp gets below around 45 degrees, the engine has a real hard time ever getting into the normal range, if ever. Not only do I imagine this is bad for the engine to be running too cool all of the time, but I can't get any heat in the car b/c the engine never gets warm enough.



Does anyone know what may be causing this dramatic change in engine temperature? I know the engine will probably run cooler in the winter months, but not even getting into the normal range or warm enough to put out anything more than a slightly warmer than ambient heat can't be normal, as it wasn't that way with the old thermostat.



I figured I must have bought a thermostat that had a lower activation point than the original, but now I'm wondering if maybe this is simply a matter of improperly mixing the antifreeze when I replaced it at the same time.



Can anyone help? Thanks!Can anti-freeze mixture affect engine temperature for Honda Civics?
You made TWO mistakes. First of all, the NAPA part is not as good as the factory part. And second,if you are using NAPA anti-freeze, you will cause engine trouble after many miles down the road. You MUST use the genuine Honda COOLANT, or the plastics in your radiator will go bad, and your cylilnder head and head gasket will prematurely corrode up. ANSWER: Go directly to Honda and buy the factory coolant and thermostat. Have them power flush your system. No more worries. WHat year is your Civic?? P.S. If your engine is running TOO COOL, it will interfere with proper fuel mixture, since it was engineered to run at a small range of temperature variations. Also, your exhaust system will premature break down from unburnt fuel mixtures. GOOD LUCK!!
it surely sounds like a defective thermostat



antifreeze with how no bearing on temps unless its frozen or lowCan anti-freeze mixture affect engine temperature for Honda Civics?
Either the thermostat is stuck open or you bought a 160 degree thermostat
Check the thermostat by boiling it in a cooking pan on the stove. Add an thermometer to it to check at which temperature it fully opens.Can anti-freeze mixture affect engine temperature for Honda Civics?
Depends. fluid mixture has no bearing, unless your running water only. But your thermostat would cause a problem, and sometimes are defective, even new ones, so I would start there. Did you burp the engine? cause I know that Civics, unless you burp the engine (getting all the air out, will cause it to run hot. Not, I had a similar situation and it turned out that one valve was burnt through..so something to consider as well. It could also be a clogged radiator that it causing the issue too. Just some things to look at. A flush you can do yourself. same with burping the coolant system. If you have down time and a new head gasket, I would check that, only if nothing else works.



good luck.
With mixing anti-freeze are you adding water to straight anti-freeze or are you adding water to premix (50/50)? If you are adding to premix then you are making your engine run cooler because premix is already mixed with water and if you add more too it then it has too much water and water makes an engine run cooler that premix or straight anti-freeze. If you are adding water to straight anti-freeze then maybe you have the mixture off and are putting too much water in the mixture. There is a tool sold called an antifreeze tester that can tell you the freezing point of the liquid in your cooling system and when you test it i believe you want the freezing point at -20 degrees Fahrenheit. If you have too much water in the mixture then if you live where it gets really cold the water might freeze and this would cause the engine to break, but if there is too much anti-freeze then it could cause the engine to run too warm and overheat. I would use the premix that is already diluted and then you know the mixture is right instead of mixing it yourself. Also how long are you running your car? Maybe it isn't running long enough to get up to that normal operating temperature. And yes not running an engine at normal operating temperatures is bad because the engine needs to run warm in order to run at maximum efficiency. Another thing is if you modified the exhaust on your car and made it bigger then you are loosing too much heat through the exhaust making it run too cool (the size of the exhaust isn't just to make a car run quiet or for pollution reasons).
Yes I believe so.