Whats up guys I have a 2002 F150 4X4 Offroad 5.4l. I went down a small dirt road and came across a mud hole, being young and stupid I thought hey I can make it through that. I however severely underestimated this mud hole and it was much deeper than expected. I made it through it no problem but it felt like I was about to break my truck in half when I went in. Now I got home no problem that night no check engine light no shaking or anything. Today I get up and start it up and my service engine soon light is on and its shaking and just doesn't sound right. My first thought is that its a spark plug or spark plug wire that got wet, any ideas?

 

You don't have plug wires. You have a COP (coil on plug). But yes, my guess would be the same as yours and I think that water got down in the plug well and is causing a misfire.

You've got it easy as when you get your codes scanned it will point right to which cylinder is misfiring.

I could be wrong - I make no promises.

 

^ this, last time i went muddin lost 2 coils and had to drive back on 6 cylinders til the cel came on and i got em swapped out with new ones, no probs since but itl sound rough and misfire til ya do

 

coil pack **** the bed along with a soaked air filter if there was water standing.

 

Also check the down line O2 sensors. They sometimes get torn up when mud rips the wire loose. It isn't too common, but does happen. It most likely is cylinder fire related, but wanted to give you a heads up on the sensors getting damaged. Good luck.

 

yup one of your coils got water and now you need new ones. Happens to me from time to time

 

Nice thinking... I have never thought of that. I've had a cat punctured one time in a rcsb dodge 360 5speed.

 

Yup it was coil number 7, was going to fix it myself but theres too much stuff to take off to get the new one in gonna have my mechanic buddy help me with it Monday.

 

I had to change my COP on cylinder 7 and didn't take anything off, just had to squish it in there. You just have to now what to feel for, because you really can't see what your doing.

 

Sorry I meant cylinder 4 rear passenger side cylinder