hi guys bought a 2009 insignia (120,00 miles with FSH), after around 3 months a code came up on dash turns out my coolant was low, topped it up no problem but 6 weeks later i decided to check again and its low again, i found it uses around half to 1 litre per month but with no leak i can find. got it pressure tested to around 1 bar by a friend but lost vert little pressure or a negligible amount. It has me baffled . Worst fear is obvious head gasket , would this show up on pressure test of...
Coolant loss
Coolant loss