Civic EG

hello, I have a problem with my car, sometimes when the revolution of rising above 4000rpm, the engine temperature rises rapidly and then when the rpm goes down, the temperature returns to normal, and sometimes the engine revolution is not stable she wanders between 1000 rpm and 2000rpm, I thought the thermostat do its could be the problem?

check your coolant. if its dirty/ low. drain the system and make shure u re fill it with 50:50 water anti freeze soloution and bleed the air from it

engine idle bouncing = air or vacume leak, probably intake gasket, can also cause your coolant problem as well since the intake manifold is water cooled, there is a port between the head and the intake, this part of the gasket has a rubber ring seal, my bet you need a intake manifold gasket.

I have been told that air pockets in the coolant can cause bouncing idle, and that can definitely cause your overheating.

I'd fill the coolant/bleed the system and see if that does it.

same prob with my car! i drained the coolant and tried to drove it around but still everything s d same. heats up when it is 4000rpm above hehhe gonna try to change my radiator to 2 rows or the thermostat maybe stock up. lolz any advice guyz/?

to extend the life of your radiatior, only use distilled water if you make your own coolant mix
All the minerals and such will cause scale buildup, which will lead to a clogged rad and overheating.

But i have definitely heard of air pockets causing an idle prob as teal_dx stated.
make sure you bleed it really good as well.

its an air leak. ima betting.

i wanna find out for sure what it is to. my car is having the same problem. i put in a new thermostat and new coolant and still them same.