Engine Misfire?
 

I have a 1998 Expedition that was running GREAT up until yesterday when I had to drive through a large puddle of water at least 1.5 to 2 feet deep to get into the parking lot at my work. I'm thinking I must have got water in or on something because I was able to drive home with no problems that day. However, when I went to leave for work the next day I could feel the car start to shake a little bit around 55 MPH, by the time I had got on the freeway my check engine light was blinking. It feels like I have a misfire on one of my spark plugs, but I'm wondering if it could be something else. I went out and looked at the number 1, 5, and 6 plugs and there was no water in the wells, which makes me think that it's not that. The car starts up easily with no problems whatsoever. If I had water in one of my wells, would it still start up easily?

I can't answer your last question, but I can tell you from several experiences the problem may just disappear as quickly as it appeared without doing anything except waiting for the moisture to dry up, wherever it is . It's a quirk that comes on after either washing the engine or going thru unusually wet areas. Give it a few days and see if it doesn't go away completely on its own. Merry Christmas !

ok thanks for the advice. ill wait a few days and hope it does. i just hope i didnt fry a plug or coil if water even got in the plug wells.

Haven't heard from you , how did you make out ?

Hey, This might help. I had a similar issue.

https://www.fordforum.com/forum/ford-expedition-21/if-you-having-multiple-misfires-your-truck-bucks-jerks-poor-start-23294/