pretty sure my head gasket [was] blown. Changed Gasket Update 4/9

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So, my wifes 03 civic lx is overheating.
have had it for a year, and its done this stuff off and on for a while. over the summer it would overheat when the ac was on and the car was sitting still. as long as you were moving or the ac was off it was fine.

i have not noticed any leaks except for the fact that it spews from the reservoir after running for a while. mainly on warmer days.

i did a pressure test to the coolant system and it held 16psi (cap rating) perfectly. even let it warm up to see if maybe things were expanding and allowing things to change, but stayed fine.
i had already replaced the radiator and fans, the fans didnt seem to be going at the right speed, both were a little slow, and since the radiator had to come out to get those, i changed it too, it was cheap enough. cap was changed then as well.
when its cold and the heat is on, heat works great as long as you are driving. start coasting or come to a stop and it goes cold.
any thoughts on what else to check, all i can think is head gasket. which i dont want. lol. but, i have no smoke or sweet smell in the exhaust. no oil in the water, no water in the oil. i can only think that there is a big enough hole to allow exhaust gasses into the coolant and causes it to push the coolant into the reservoir and blow out. havnt done a sniff test yet. school lets out after the 11th, then i can devote more time, which i mean i will have to.
That was also my first thought. If the thermostat is stuck shut your coolant won't circulate and carry the heat away to the radiator. Quick way to check is to get up to temp and compare the temperature of the upper and lower hoses coming out of the radiator.
the civic's with the 1.7 are notorious for blowing head gaskets.
my old lady had one and it popped around 80k miles. it ended up losing heat in the winter below 2000 rpm's
we went through all the normal shit, thermostat, water pump, head gasket with head shaved, i think maybe something was wrong with the block.
it still had no heat below 2k rpm after the new head gasket so i ended up sourcing a low mileage junk motor.
that motor had about 90k on it when it went in and made it another 80k before it started having the same issue.
i wasn't going through that again so i ended up selling the car as is after she got something newer.
it is probably the head gasket pushing gas into the coolant passages. don't let it keep getting hot or you run the risk of fucking up the block.
if you have the head gasket done i would suggest that they mill both the head and deck the block. that's the one step i didn't do.
i had the head done but did not pull the block out of the car.

my advice to my OL was to have her take it to honda so there was a shot at them knowing what the situation was with it and getting it fixed right the first time. this is my suggestion to you as well. if a giant kick in the dick to rip the whole motor down and mill the head and put on a new headgasket, just to have a no heat situation again.
Just dump it and pick something else up.
Well, replaced the head gasket. Such a pain in the fucking ass. had it machined and cleaned up. got everything put back together tonight. starts right up with no hesitation and fill up with coolant. drive around for a bit with no issues. fan cuts on at 208 degrees, keeps at about 195-200 ish while driving. no big problems as of yet.


when idling there is an odd popping noise i believe coming from the intake side of the motor. pop isnt a great description of it really, kind of a burst of air like the intake gasket is leaking. sounds consistent with perhaps one of the cylinders. i sprayed carb cleaner all around and there was no response to that, and the idle is smooth at the correct rpm range. CEL is on at the moment, but only bc I started it before putting the whole intake on and it set the code for the air intake temp sensor, other than that one no codes and none pending.
It drives fine (so far) but it was also early evening when i did the the test drive so once I drive it on the interstate in the heat of the day I will know for sure.

I will try to upload a video of the noise from my phone. if i can figure this out without having to take off the intake i will be a happy camper.
not going to upload directly from phone bc the file type isnt allowed. oh well, will try tomorrow sometime. not sure if it will be of any use though, watching the video it just sounds like a knock, which it most definitely is not. in person its a bit more airy and is seems to be coming from the top side of the intake area.