So my car started overheating out of the random. Won't overheat if im driving it in the city. Once on the highway and during WOT it will still stay cool, but once i slow down the temp starts going up and then just back to normal. Does it every once in a while. What should i be looking for?


its a ls/vtec. new oem headgasket and waterpump less then 5k miles ago. Just installed a new thermostat and still nothing. Also the after driving it for a while both hoses are hard but only the top one is hot and the bottom one is ice cold. Only thing i haven't changed is the radiotar and it does look old. Could it be clogged?

 

Well if you've changed everything but the radiator, change that and see what happens.

 

Try sitting stationary. Let it get hot if it starts to overheat rev the engine, and see if your cooling issue comes back.

Next try putting a fan in front of the engine see if that eliminates your problem.

Is your cooling fan working properly? If not make sure the fan is working and the fan switch is good.

If your concerned w/ the cyl head do a comp test to get a idea.

But i would focus on the fan and fan switch first

 

deff dont let it overheat then rev it, honda motors dont do well when they overheat...99.9% chance its you radiator size and or fan...check to see if the fan works first

 

You dont let it over heat. You let it get above normal coolant temp then you run the rpm up.

I should be a little more clear i guess. Once the coolant gauge reaches halfway is when the coolant temp is above normal

 

Have you tried "burping" your coolant system? Since you have recently changed some system components you may have got some air trapped in the system.

 

id check the thermostat first and or radiator but might be the head gasket too, had to change my sisters head gasket out on her 02 civic cuz she was having her cars radiator fluid needing to be filled frequently and the radiator was new.no cracks in the block or leaking hoses.

 

Cooling fan is direct, so its always on. I tried burping the system..left the car on for a about an hour with the rad cap off and the heat on and off. It will NOT over heat if its just sitting idling.