I have tried everything. The car gets hella pressure when im driving. If I have the cap off the radiator and rev the engine the water comes out of the radiator if I drive my car it overheats but when I stop and idle it doesn't. I will drive it then there Will get hella pressure and the restore will fill and water will come from it. I checked the hoses. Took out the thermostat. No oil in the water. No water in the oil. No smoke. No leaks. Engine has great compression. Bypassing the heater core. Wtf is wrong!!!!! Please help. D15b7

 

Question: why does my car overheat?!?
Answer: Because there is explosions inside of it.

...The real answer is probably the thermostat isn't opening or the fan isn't turning on.

 

Bleed the coolant system. Check to see if the thermostat is opening (boiling water on a stove is the common bench test). Make sure the fan switch is operating (this isn't the issue, you'd have over heating issues at idle if it were).

 

prolly has a clog in radiator use a temp laser gun to test temps all over radiator

 

battling this same issue on a later civic.

replaced (1 by 1 but not in this order):

radiator
radiator cap
thermostat
coolant 50/50 with distilled water

in the process of overheating several hoses have blown with obvious leaks. but no leaks now.

fan turns on.

no excessive water vapor out of exhaust, or evidence of combustion gases in coolant. so not a blown head gasket.

always burped or made sure coolant was topped off.

would still overheat and eventually lose coolant. lose my ******* mind.

ive resolved that it has to be the water pump, specifically the bearing seal. i wont bother replacing it, i'd rather salvage the car for other reasons. the overheating process has really tired out the engine, wont idle smoothly anymore anyway. not worth saving.

if your story is like mine, then try replacing the water pump too.

but honestly i wish i could confirm it is indeed a water pump problem, im just not going to dump any more money and time into this. it can runabout town as needed as long the coolant is topped off frequently and turn the heater on to help cool the engine as needed. until i replace the car.

 

Does it just pour over? Or does it come out with some force?

If it's coming out with some force then it's likely a leaking headgasket.

 

or the radiator is clogged.


pouring over is normal, its just the water pump spooling up the coolant.

 

^^ The engine or the outlet port of the radiator would have to be clogged. Internal radiator clog won't have the flow to shoot water out

 

Not having a thermostat will cause coolant flow all the time, which on some cars will produce a big mess with the cap off, cold or not.

Does the engine "spit" coolant while cold?

Why would you bypass the heater core? Does it not produce any heat?

What preceded this problem? It sounds like your throwing mud at the wall. Take a step back and go though the problem start to finish if you want more than just a guess.

 

Turning the A/C-heat **** to cool [blue] turns the heater core off. No need to block or remove the heater core. You do not get colder A/C air turning the **** all the left [blue], you are just turning the heater off. With A/C on and turning **** to heat [red] you are not getting less colder air, you are adding heat. A/C compressor output is constant.