2006 Mazdaspeed/MPS 6
Yeah, it is displaced into the reservoir (it's not completely empty, I think). So every time I "blow" it back into the system, after a short drive it gets pushed back into the reservoir. But the drive is short enough that the remaining coolant doesn't boil, it's just that the circulation fails due to the empty rad hose (and any excess gas/air is pushed through the reservoir).Well, if the coolant is being displaced by air it needs to go somewhere, and that’s a lot of missing coolant. That’s too much to fit into an already filled reservoir.
How’s your oil?
No, the coolant is not at the top of the radiator neck when the engine cools down. It's difficult to explain, but I will try to put it "chronologically":I’m a little confused. If the coolant is at the top of the radiator neck when the engine cools down, and the reservoir is near the full line, how is there room in the reservoir for the extra displaced coolant when the car heats up?
Yes I meant if the oil had coolant contamination.
I don’t think he is filling up the radiator. Rather, he transfers coolant from the overflow into the radiator. So it sounds to me like he’s just low on coolant and as it circulates the air is getting trapped in the upper radiator hose, and there isn’t enough coolant to naturally bleed out that air.If coolant level not at top of radiator after short drive, and previously you filled it up, then only reason is loose of tightness in coolant system.
I.e. leaks of coolant or leaks of combustion gases thru HG.
If tighten coolant is sucked from the expansion tank when engine cooling down.
Did they explain why a cracked head vs. a head gasket failure? Personally I’d be suspicious at an ambitious diagnosis like that, even if they had looked at it in person (unless there are visible cracks, assuming a cracked head vs head gasket failure is not the logical first assumption).Just had a call. The dealer suspects a cracked head.