Coil pack HV electrode corrosion

[ftuhy]

Eight months & 2000 miles ago I changed spark plugs (at 60kmi). At that time I had radio noise, and discovered corrosion on the top of spark plug 5 & on the internal high voltage (HV) electrode contact of the coil pack. The new plug and thoroughly cleaning the coil pack HV electrode cured the radio noise problem.

Recently my radio noise came back, and once again there's HV electrode corrosion in coil pack 5. Note that everything is dry as a bone. No corrosion/rust/oxidation on the spark plug body; no moisture in the spark plug well. Even the valve cover well for the coil packs is dry with no sign of any water tracks in the dust.

So, my only conclusion at this time is the coil pack has an internal leak, and some type of dielectric fluid is escaping. Anyone have a similar experience with the coil packs?

When I changed the plugs 8 months ago, there was a very tiny amount of corrosion on pack 1 in the same place. I think I'll replace both packs 1 & 5 to avoid future problems.

 

[pgilliam1]

I never heard of any fluid leak from a coil pack. Sounds to me like you have some arcing going on. If it was mine, I would soak all the coil packs (inside the stem and complete outside) with silicone spray several times and then dry the excess off and try it again. The silicone brings back the softness and pliability of rubber and helps to seal any arcing gaps.
Good Luck!

 

[ftuhy]

All the rubber is soft and flexible, and was coated with silicon grease - I do that on anything rubber in the car to keep it soft. I even removed the small spring inside the coil pack boot and cleaned it separately.

With the plug removed, I inserted it into the coil pack & could feel the spring compress. The plug slides out of the boot easily, but with a "pop" indicating a good airtight seal.

I was careful not to get silicon on the spring, metal coil contacts & the metal contact on the spark plug. Silicon is an insulator and the spark would have to arc through it, losing some energy.

Out of curiousity I'll see how long this cleaning lasts.