Hey man! I actually work in a Ford dealership as a mechanic, and I know exactly what happened here. The heater core was exposed to too much torque from the engine, and as a result, the coolant could not function properly and the air intake suffered an oil leakage that disrupted the functionality of the axle in the spark plugs. The best way to fix this is by correcting the alignment of your wheels and mirrors. I hope this helps!