2020 250 6.2 SD gas, 43000 miles

The HF Ham transceiver powered from the 60 amp 120VAC inverter line ( inverter disconnected) became so extremely noisy on receive that it couldnt be used while driving. Ignition noise. It wasnt that way a few years back.

Three outboard spark plugs were completely oil fouled, probably from overfilling the engine oil. Cylinders 1, 2 and 3. Light oil film in the PCV valve and line to the throttle body. I had probably overfilled it 3/4 ths of a quart at least once. A Ford mech said a half quart shouldnt hurt. Usually its the rear plugs thag foul from excess oil.

Most of the inboard plugs were misfiring due to moisture that caused oxidation between the spring on the COP unit and plug electrode terminal. Inboard # 6 plug threads had severe oxidation buildup on all the threads suggesting the threads were wet when the plug was originally installed. The threads were covered with white powder.

Ive replaced all but four on the PS rear so far, the engines never run this well, much more ' snap' at takeoff.

Theres something EXTREMELY important, especially in engines with two spark plugs per cylinder, that caused extreme problems with the 84-87 Honda Goldwings...severe ignition noise and charging system failure...

It is critical to clean the threads in the heads!

These plugs are not ' grounded' to the heads, the circuit is from the COP, thru both plugs and back to the COP unit! Any spark plug thread connection thats contaminated with oil, oxides, rust or loose threads will reduce spark voltage and cause ignition noise to be reflected back into the primary electrical system. I had measured 400 VOLT IGNITION SPIKES on the GL1200 charging system due SOLELY TO CONTAMINATED SPARK PLUG THREADS! This is worse with two plugs per cylinder.

Although ' nobody does it' , its VITAL that ALL fastener threads be clean for proper torque, especially spark plug threads which are high voltage electrical connections with two in series. Contaminants, especially oxides, are very abrasive and can cause aluminum thread damage. If the threads arent clean the spark plug torque will be LOW.

This video explains how to do spark plug changes and minimize or eliminate cylinder head damage, Ive done this procedure since the early 1990s.

Video on how to remove and replace spark plugs in aluminum heads without damaging the aluminum threads:

 

When I changed my plugs, wires, and coils last fall 56,000mi, I noticed on the top plugs that had the green corrosion, the bolts that hold the coils had more corrosion than those holding the coils on the plugs with no corrosion.

the corroded pellets between the coil terminal and the spring definitely I could see creating an electrical “noise”. Same with any arcing that occurs in the hole where the COP sits.

 

Damn good video.

Only disagree about the torque wrench. Because Im a technician with a calibrated hand. Sometimes there just isnt room to use one perfectly. But if a TW can cleanly fit in there, I use it.

If youre not towing, the 6.2 can go longer between plug changes, as long as you dont overfill oil. Half way up stick, is fine. Every 50k, with coils, is a bit expensive.