dlx111

So I’ve read alot of threads out there with different overheating and cooling scenarios, but I cant seem to get a good picture of what may be going on in my situation.

So engine wise car is bone stock 95 Civic D series 230k mile motor with new head and headgasket. CXracing dual core half rad and cx slim pull fan with OEM shroud. All new OEM hoses and OEM thermostat. Thermostat confirmed working opening around 180 degrees. Timing belt and water pump replaced at around 180k miles. Using 80% coolant and rest purified water. Also have holes cut in the front bumper for extra air flow.

Whats going on with the car is in normal around town driving it will get to 180 degrees and very slowly continue to increase. I have my rad fan wired to a switch because the fan would sometimes kick on and sometimes not which lead to me overheating a few times and testing/replacing the fan switch which was good. So i kick my fan on when the temps get to about 190 only because i dont want to overheat again.

For a few months I ran the car without a thermostat and the car seemed to cool more predictably.

In Florida right now its about 100 degrees out and with my AC on the cars temps get hotter faster and stay hotter even with the rad fan on.

Today on the highway with AC on just driving the temp was slowly increasing, which was odd because without my thermostat in my temps would slowly go down..as they should.

To me a stock car with no obvious mechanical issues shouldnt be having issues staying at normal temps. Im taking measures turbo guys go to to stay cool like cutting bumper, venting hood, heat shielding, etc all to keep a stock motor car from running hot..doesnt make sense. And to be clear my hood is not vented...yet lol.

My thoughts right now are that maybe this half rad is a piece of crap? Maybe my water pump is a piece of crap? Idk

mk378

Don't use more than 50% coolant. Read the instructions on the bottle. (60% might be used for more freeze protection in extreme cold but that is not optimal for summer, and never necessary in Florida.)

Make sure the radiator is staying completely full. Check when the engine is cold before driving the first time of the day. Another check if there is air in the system is to see if the heater works.

Normal operating temperature is 195. Use a stock thermostat, the engine controls are designed for that. Occasional excursions above 200 are to be expected.

Aftermarket bling of any sort is suspect.

dlx111

The thermostat is stock OEM for my model. In theory the radiator is supposed to cool the coolant and when the stat opens that cool water enters and then hot water is then cooled in the radiator, eventually the cooler water will shut the stat and repeat...right? I feel like the “cooler” water isnt actually cool and the whole system just runs hot.

What i feel like im noticing is system stays around operating temp but will only climb not come back down like its supposed to.

Worth noting also i have a separate temp gauge wired to a sensor in the rad hose, i know its not accurate as to the temp in the head but my stock temp gauge is broke so.

dlx111

I will try doing a 50/50 tho

TomCat39

This.

I assume you did some research on coolant to learn you are reducing thermal transfer by running more coolant than a 50/50 mix. Same is true by running less than a 50/50 mix. 50/50 is the magic number.

muellersfan

Properly and thoroughly bleed the cooling system. You'll find the correct procedure in the service manual, which you can download.

Then go from there.

tamboo

the lisle funnel kit is worth it if you have trouble bleeding.
you'll know when air hits the coolant temp sensor. bucking bronco antics will ensue lol.

https://www.ebay.com/itm/New-Lisle-2...QAAOSwGelcW4sI