mekirk2

I know this has been rehashed over and over on the forums, but I have a new situation (I think). I had the spark plugs replaced 5000 miles ago, all new Motorcraft plugs. This weekend I had a coolant leak on the engine, blew coolant all over the engine. When this happened, a misfire appeared. I assumed it was from coolant getting on one of the coil packs, but the check engine light didnt come on. My mechanic could not get a code to pull, but found a misfire in Cyl 2 while testing, so I replaced that coil pack. That didnt fix the issue, so he recommended I replace that plug again.

Heres the questions. First, should I replace a 5000 mile old plug that I have driven for 200 miles with a slight misfire (not misfiring all the time)? Would it already be fouled and need replacing? Second, if it is the cam position sensor, where is it located and how hard is it to change?

Also, anyone else have any other thoughts?

Thanks!

Dirtbuster1

If you had a coolant leak on the intake, water or antifreeze could have gotten in the spark plug holes. If water got in the holes, it can drive the COP's crazy. It would be best to remove all of the COP's, and spray contact cleaner in the holes to dry up everything. Then apply die-electric grease to all of the boots, to prevent further contamination. Clean everything good, and you should be ok.

Good Luck

mekirk2

Dirtbuster,

I think you hit the nail on the head, at least I hope so anyway.

As I mentioned earlier, I replaced coil #2 because the mechanic said it was misfiring randomly, cleaned the spark plug hole when I replaced it. After posting, I thought "that didnt fix it, so I'll take the old #2 coil and put it in #1" (because #1 and #2 had the most exposure to the leak). I pulled #1 COP and the hole had a little coolant in it and the spring was corroded. The boot was also damp all the way down. I coated everything in the old COP with dielectric grease, including the electrical plug, and put it back together.

It only misfired when it was warm, so I'll have to wait until tomorrow to get it out and drive it. I'll let you know if it fixes it.

Everyone feel free to share any other thoughts and thanks for the help!

ImSofaKingWeToddId

Whats caused the coolant to go all over the engine? If you have a misfire, go around the block and give it a little gas to make the misfire a little worse so the sensor picks it up. Sometimes just at idle with a misfire its not bad enough to cause the sensor to pick up the knock. Any moisture in those cops with cause em to act up. If you say you had coolant in the hole where the plug is that will do it. Also that coolant all over the engine isn't good. I'm guessing you hosed off the engine afterwards. May have gotten some water in a couple of them. depending on how much coolant got on the engine, I'd blow out all the holes with an air gun and change the plugs, clean the cops, and put new dielectric grease on em.