3.0 ranger Ford flex fuel automatic
My #3 spark plug very clean compared to the rest of the others, I keep getting a #3 misfire code, I get bubbles in my expansion tank when running, not Extreme. I am thinking somehow coolant is seeping into #3 cylinder, im not adding coolant often but weeks go by and I check level and it's low. I check oil level and no indication of coolant, no gray looking sludge, actually very clean and no oil consumption. My suspicion is the intake manifold leaking into #3 combustion chamber. Also it holds pressure in system all the time, when i relieve pressure it feels like air pressure not coolant pressure. Did pressure test, and pressure holds. So I am baffled. I am more than grateful to hear your wisdom, Thank you.
The coolant is either leaking or burning. Any white smoke from the exhaust pipe?
No white smoke visible, but the engine check lite goes out for day or two then returns back on and I can feel a misfire when it does. At one point it went out for at least 6 months. The returned when I opened the system to flush heater core.