right ive had a recoditioned head on my vr6 new head gasket etc back in 2011 now i found out the oil cooler wasnt connected but i have now sorted that but my header tank is boiling water spluttering out if i put the cap on it pressurises. but it never overheats fans kick in heater sometimes blows warm oil seems clear on oil cap tried running it without therostat and also tested the thermostat.