So I fixed the no-start problem and it was running fine. But last night after getting off the freeway, it showed signs of a blown head gasket after getting off the freeway. White sweet smelling smoke out the back, barely idled, and then wouldn't start. Today it started fine no problem. Could this be an early sign of failure? As in, it only leaks at operating temperature? The plugs looked fine. Oil looked fine. Coolant level was fine.