Being an older model the heater core may be full of mud,
well worth removing and taking it to a radiator place to test and inspect
Being an older model the heater core may be full of mud,
well worth removing and taking it to a radiator place to test and inspect
G'day mate, I don't know about the MK in particular, but if you already have the heater bypassed, I would take it out and get a rediator shop to have a look at it. your blown head gasket, heater leak...