Hey guys

So I have a 90 crx with a jap spec b16a motor which intermittently overheats. I have come to the conclusion that it only happens when I hit vtec and/or just gun it while driving. If I take it easy and do not hit vtec it does not overheat. I have replaced thermo, flushed Collingwood system and bled, changed fan to see constant power while car is on. Only thing not replaced is rad and water pump. Heat gets hot and both rad hoses are warmish. Any ideas would be great. Any question just ask.
Thanks

 

Headgaskest imo, only overheats with high cylinder pressure. Saw the same thing with a gsr swap in my wife's car

 

A compression test will tell ya if the head gasket is leaking.

 

Not always. A compression test cannot simulate the actual pressure of combustion which is far more than the pumping pressure of the engine. I the engine I mentioned it had excellent leakdown and compression. New gasket, surfaced head and new fasteners and it never overheats. The other symptom w saw was a wandering temp needle as well.

 

I did a compression test and it was fine. No milky oil neither. I was told by someone that I could be something to do with the impeller on the water pump? High rpms it will slip off or something.