Rep Power: 0

Hey y’all, I recently bought a 2005 civic DX sedan. Ever since I’ve bought it whenever I use the AC my engine temp fluctuates a few ticks when the car is not moving and in park, but when I drive it settled back to normal operating temp. When I come to a stop at a light, the temperate heats up more than resting, but holds steady and drops back down when I start moving again. I just replaced my reservoir because there was coolant coming out from under the cap, and that seems to have solved the leak issue. Any ideas why the engine temp changes that much with the AC running? (The temperature doesn’t change at all when I’m driving with the air conditioning off.)

 
Rep Power: 368

do the test in the 1st post (video) to confirm if head gasket or not
if pass, move on to other potential causes
https://www.civicforums.com/forums/3...reference.html

 
Rep Power: 51

Yup. I just did my head gasket and head rebuild after doing the water pump. First start and 50 mile shakedown it Runs like a top but is hitting the high side when going uphill or running the AC.

I am thinking this is now just a radiator issue. Since Everything else on mine is new. Any advice on the age of an original radiator that way have been mistreated and what is their general life expectancy?

 
Rep Power: 368

honestly, not common to hear actual radiator failing other than heater core clogs or similar? recently there was one with a hole in the rad neck.
or people using stop leak? (engine goes before rad when using stop leak, so...)
my 02 is still doing fine, for example
thermostat, cap, etc new? Hoses might go first

 
Rep Power: 223

Just because the headgasket was just done doesn't mean that it isn't still leaking. Do the test.
Did you bleed the coolant properly?