Continuing the saga----04 F250 5.4 Triton, started hesitating at idle and under load. I pulled the plugs and noticed

1. Surface moisture on the plug boots when I removed them.
2. Rust on hex porton of plug.
3. Electrode looked normal (worn at .060)
4. some corrosion on the lower part of the spring that connects plug to COP within the rubber boot.

I didnt see any obvious visible signs of water leakage in the area of this plug (2nd from front on passenger side.

What could be causing this? Any suggestions or similar experiences?

 

Check the boots for cracks and I always use tons of the dielectric grease to keep moisture out. Are you having any coolant loss?

 

X2 on the die-electric grease. NAPA, Echlin brand (I think its part # is ML2) is what I’ve used for years. Red & white tube. Makes the boots come off easier on all plug wires. It has many other uses in the automotive world like your trailer light hook ups, bulb sockets etc...Keeps the corrosion off the delicate receptacles.

 

my guess is just water getting up into the engine bay from PO offroading, or just driving throu heavy rain/deep puddles..