Dylan29 , 31 Minutes Ago
Hello all, I have a 97 Civic EX and I recently did a coolant flush and replace my coolant with 50/50 Prestone anti-freeze and I replace the cap with an oem. After about two weeks I started to get a temperature fluctuation at idle it wouldn't get really hot but it would go above the halfway point. I went to go check on my coolant level and noticed that my reservoir tank was overflowing but the was kind of low. So I took coolant out of the Overflow put it back in the radiator turn the car on and I put about a quarter gallon of antifreeze and it would not stop bubbling. So I figured it might have been the head gasket so I got an engine block tester from AutoZone and the coolant tested negative 5 times for hydrocarbons and after every test just to make sure the test solution worked I put the test on the http://www.autopartswarehouse.com/search/?Ntt=exhaust&searchType=global&shopId=1&N=0&addfitment=1pipe and it immediately turned yellow. So I replaced the cap and about a week and a half later today I was experiencing temperature fluctuations at idle again. Went to go check coolant level this time the Overflow was about halfway filled and the was about 2 in below filled. Now I haven't seen any leaking overnight and my radiator fan is working. What else could it be?

 

Probably need a new thermostat.