The other day my 2003 2.3L with 136k miles started missing after a 10 mile drive. When I raised the hood I noticed the #2 plug wire had popped off. I put it back on and all was fine. The next day after about 10 miles of driving it did it again. I put it back on and drove about 10 miles and it did it a third time. I pulled the plug out and there is some oil around the plug (the common leaking valve cover gasket). I pulled out the #1 plug and it was dry. I tested how the plugs snap into the plug wires while they were removed and the #1 and #2 plugs seem to snap in to their respective plug wires with about the same effort.

Is it possible that the bad valve cover gasket around #2 could be causing this problem? If there was so much oil that it was getting up inside the plug wire boot I guess I could see it. But there wasn't THAT much oil. Any ideas on what could be causing this? The plug wires are about 2 years old and are Motocraft wires.

I plan on replacing the valve cover gasket this fall (it is leaking on the front bad too). Does anyone have any suggestions on brands? Obviously the Motocraft stuff isn't so great because they all seem to leak. Would Fel-Pro be an upgrade?

Thanks!

 

Dry out the spark plug boot, stick in a paper towel or ?? to get it clean and dry inside.
Also clean spark plug as much as possible

Put it back on then try to pull it off again, should be suction when trying to remove it

If thats the only cylinder with oil at the spark plug and the only boot popping off then its a good bet the oil is the problem.

I would try to clean out as much oil as possible and see how long the boot stays inplace

 

I did that last night. There really wasn't any oil up in the boot. Honestly when I pulled boot out I saw no evidence of oil on the boot. In hindsight, the dielectric grease on the very bottom of the boot was slightly brown, but that was it. I didn't know there was oil in there until I put my spark plug socket down in there and it came out with oil on the very bottom of it.

However I did clean out the boot and the spark plug as much as possible and I drove it today. I made it about 10 miles so hopefully it stays on until I can replace the gasket in a month or two. Thanks.

 

I had a problem with a boot popping off a few years ago. Turned out to be a bad plug allowing cylinder compression to leak through, something with the core and insulator. Stumped me quite awhile till an old timer suggested it. Said it's rare but does happen.

 

I also recommend slightly pinching the contact inside the boot, on the duratec you need deep needle nose pliers. Sometimes they expand and don't "click" on properly. Even brand new wires do this sometimes. If the contact grips the plug tip appropriately it should never pull out. Also with a properly greased boot it should be water/oil proof so even if the valve cover is leaking it should not leak into the boot in my opinion.

 

I read that in some other forum too. These plugs have about 35k miles on them. They aren't too expensive so it might be worth replacing since they are so easy to get too. Thanks for the tip.

 

Or swap 2 plugs and see if the problem follows the spark plug

 

That is a good (and cheaper) idea. Also, since I cleaned all of the oil off and removed/reinstalled the spark plug on #2 it hasn't popped off again. But I have only only been on 2 trips.