OEM 2006 Mercury Mountaineer Spark Plug

2006 Mercury Mountaineer Spark Plug Parts Q&A

• Q: How to inspect a spark plug for issues such as bridged gaps, deposit build-up, oil fouling, carbon fouling, normal burning, pre-ignition, overheating, and fused deposits on 2006 Mercury Mountaineer?

  A: Examine the spark plug for a bridged gap which indicates excessive buildup of deposits between electrodes properties of oil and carbon fouling. The spark plug should be cleaned when needed. Verify the presence of oil fouling through black wet deposits on the insulator shell bore electrodes because of excessive oil that enters the combustion chamber from worn rings and pistons along with excessive valve-to-guide clearance or worn or loose bearings. Repair possible oil leaks before installing a new spark plug. Inspect the spark plug for black dry carbon deposits on both the insulator tips and shell surfaces and electrodes since these signs might indicate wrong heat ranges or filthy air filters or too-rich mixtures or too much engine idling. Clean the spark plug in this situation. The inspection for normal combustion appearance consists of checking for either gray or light tan residue on the firing tip. If the electrode shows signs of melting alongside a broken insulator then metal deposits will warn of possible engine harm due to incorrect ignition timing or illegal hell-coil insertion or wrong fuel choice thus requiring a new spark plug installation. The combination of engine overheating with the wrong fuel type and loose spark plugs along with spark plugs having incorrect heat range or low fuel pressure or poor ignition timing will create white or light gray spots and a bluish-burnt appearance on electrodes. This problem necessitates replacing the spark plug. Fused deposits which resemble bubbles or blisters should be checked because they result from quick accelerations at which time you should clean the spark plug.