tricko82

hi all, just bought a is200 everything was ok then last week we started loosing coolant, it seemed to be comming out from the resovior tank, we took out thermostat, still happend ,put new rad cap on seems to be a bit better,but still losing coolant, but only at high speeds it seems to lose alot,the car isint over heating, only when then the coolant is running low, theres seems to be no obvious sighns of a head gasket gone, has anyone got any idea what it could be, thanks in advance