By the way, usually when my car overheats the expansion tank fills up.
Id been for a drive somewhere, got home, and putthe car away under its cover. ...2 weeks later I get the car back out. I lift the bonnet to check the coolant before starting the engine, and I notice the expansion tank it already full. (Like it’s overheated)
does this prove that it has headgasket failure.? As the coolant is not allowing to get back into the system once the car is cool, due to exhaust gases thatve taken it’s place .?