Big rain and big problem... sevice light on and running bad... need help


2000 F-150 harley edition… V8 75000 miles. no mods… went through a serious Thunderstorm friday, big puddles… service engine light came on truck running rough and bad… truck starts OK and runs but poorly… any body got a hint before I donate to a dealer… I’m in the boonys and service is a haul… any help will be big since vacation coming up… thanks ahead of time…

I’ve been here before with my yukon but that was a few computers and servers ago so I’m starting fresh…

great site here…


If you have an AutoZone or AdvanceAuto Parts store in your area, drive out to them and have them read the codes(will most likely do this for free), when you get the codes, post them back on here. They should also tell you what the codes mean when they read them for you.


Might check the obvious–look for water in the ignition components, and any connectors that might have been pulled off by a wave of water. Keep in mind that driving it like this on a long trip to the dealer might cause damage to the catalytic converter or other components. On most newer cars there’s a way to read the codes without a scanner–can anyone help here? If the truck has a digital odometer (as opposed to the type that are mechanical and the numbers roll up), you might try holding down the trip counter button while turning on the ignition–continue to hold the button down for about 5 seconds or until something changes on the display. It should test the gauges & lights, and may end up reading out any trouble codes.


Ok, got back from autozone and advanced auto… 50 mile round trip…(little late on the warning!) went to the first one… here is the code…

cylinder 2 misfire detected
cylinder 5 misfire detected

he said could be plugs, wires or these coil things…

went to the second place…

same codes as first…
this guy showed me under the hood, little too involved for me to do…

so anyway, driving home it hit me, why would 2 go at once? do 2 and 5 have anything in common? am I barking up the wrong tree?

thanks for the help!


why would 2 go at once? do 2 and 5 have anything in common? am I barking up the wrong tree?

Yea, the wrong tree.

Likely the wires to those two plugs were the worse of the lot. When they got wet they both failed. The others are like to follow shortly. It is even possible that as they dry out they may start working again, for a while.

Replace the plug wires and likely the plugs need it also. In the event that does not do it do the coils.

Don’t buy any fancy designer wires or plugs. Best bet is to stick the OEM brand and type.


Maybe not. If this has coil packs instead of a distributor, then each coil pack feeds two cylinders. If the same coil pack feeds both 2 and 5, then you probably have a bad coil pack.


While I may not agree with Joe about the wrong tree, I’m 100% with him about using only OEM grade replacements. Most of the High Performance wires do not work with OEM ignitions systems and actually decrease performance.


With only 75k that truck is barely broken in.
The engine uses coil on plug and since you have a misfire on multiple cylinders the coils need to come off and the plugs should be replaced.

You ran through deep water and the 2 cylinders that have developed a miss are located near the front of the engine; one on each side. These would be more likely to allow water to run inside the spark plug tube.

A borderline spark plug combined with a tiny bit of moisture and there’s your miss.
Chances are the coils are fine (hopefully) and the only thing you should replace are the plugs and boots.

If you continue to operate the truck with it running this badly then you will definitely cause some more damage over time; knocked out coils, clogged O2s, clogged and overheating converters, etc.


thanks for the info… I’ve learned alot this afternoon… Coils, plugs etc… just looked under the hood and way past my ability… gonna drop it off at a fair dealer in the morning along with the info you provided… this way hopefully I’ll only get half raped! thanks again and I’ll be back soon with results…


Keith may well be right. I was thinking that a single coil feeding two cylinders was not done on a six or eight cylinder, but I am not sure. I defer to Keith’s experience on this one.


Ok here is the scoop… waited home till wed afternoon… thats 3 full days and they never even looked at it! guy said sorry, you can pick it up and take it elsewhere… so I did… ran down, grabbed the keys and smoked em… that place is off my list! Got on the road, light was still on but wasn’t missing anymore, running good… got to a ford dealer and told him the story… he said if its running good don’t touch it… I’d be just throwing money away…he turned off the service light… he said he sees it all the time… alot with guys washing with pressure washers… even the detailers at their place! anyway he said after 6 days they must have dried out… went home, hooked up the boat grabbed a 12 pack and went fishing! caught a 12"er! thanks for the input, all very informative… I now know what a cop is and I can’t even change a sparkplug on my harley…


i had a problem simlar to yours on a 2000 ford expediation you have a an a/c hose on the right side that when on lets water run down on the #2 and #3 sparks a simple shield will cure this i bet if you look @ the otherside you will find another hose or line creating the same problem


The coils drying out is more than likely what happened.
Consider carrying around a can of WD-40 and spray the coils down with it during times like this; even on a regular basis.
WD is silicone based and will repel water.

I’ve got a couple of old Harleys myself and while the plugs are easy to change they’re definitely not cheap.
My old flathead uses the air-cooled plugs and I saw where a pair of NOS plugs sold on eBay last year for 500 bucks. 250 each makes me head to the beer store too. :frowning:


I’ll bet your information is correct Glenn and that is what happened here.