Every time I turn off the engine when the car's been running at operating temp, it chucks some water out of the overflow past the radiator cap. I've got the same pressure cap as an S13, but when I measure the top of my radiator cap in comparison to the engine, against a standard S13, mine sits about an inch lower.
I think this is causing problems, so i've now got an S13 non pressure overflow bottle mounted on the inner wing at roughly rocker cover level. Would it be better fitting a non pressure cap to the radiator and a pressurised expansion tank at the same height on the inner wing?
Help!!! I don't want to cook a good engine!