I have a misfire that occurs only during start-up and pretty infrequently and goes just long enough to set the check engine light. It happens maybe once every couple of weeks and only during a cold start. It then resolves itself and doesn't happen again for days. When I scan the engine the counts for the misfire are really low, like 11 of them. I've replaced the spark plugs (which were due since the car has 120k miles on it) and the coil pack on cylinder 4. Any idea on what could be causing this?
I should add that the car isn't burning any oil and isn't showing any signs of bad head gasket (the oil looks perfect when it comes out).
Head gasket failures on this engine start slow and misfire occasionally on cold starts. They don't leak oil into the oil routinely, they will leak a small amount of coolant into the cylinder. It then burns off. Often owners do not immediately notice coolant loss as the leak may seal when warmed up, at least for a period. Watch the coolant carefully.
