I'm a dummy, I admit it. I wanted to clean my engine (1998 F150 5.4L) and I took a quick swipe at the engine last night with a low-pressure powerwasher yesterday. Truck seemed to go fine during the morning commute (30minutes), however coming home it chugged and the whole truck would shake violently sparatically, especially when accelerating around 30-40mph. My check engine light flashed a few times and then remained solid. I don't have a reader, and haven't been to Autozone for them to read it... Maybe misfiring?

Any ideas? I assume its probably related to washing the engine?? Can I still drive the truck to work without killing the truck until I can get a mechanic to look at it? Thanks. Matt

 

Water likely got down into the plug wells, causing misfires. Prolly won't hurt nothing to ride it around until you can get it looked at, assuming you ain't making no long trips or nothin'. Power washing these engines is a bad idea in general, you've got to be very detailed in securing and wrapping things up to prevent water intrusion into things that don't need to be wet.

 

Is there a way for me to clean the plug-wells? A towel, etc??? Or do I really need to hire a mechanic to do it? How about dry gas?? Would that cause my check engine light to go on?

Thanks.

 

Removing the coils and using compressed air is probably your best bet, or maybe a shot of WD40.

 

When you say "remove the coils" could you help me locate the coils...Is the coil the rubber boot that goes over a spark plug? Also, is the plug-well the area that the sparkplug screws into on the engine? I'm not a mechanic, but would like to try your ideas...Is that where I spray the air/WD-40? Thanks!

 

Um...accessing the coils might not be something you want to mess with if you're not well in the know. Especially the rear most ones, that can be rough to get to. Next to the injectors, black circular shaped things with two pin connectors on them and little 7mm bolts holding them to the intake manifold...those are the coils.

 

I just looked under the hood and think I found them, as you described. It looks too complex to get the rear ones. Should I just spray the WD40 in that general area (all over the engine block and coils, etc) even though I can't remove them?

What if I do nothing? Will these dry out eventually in a day or two? Will the heat of the engine evaporate it?

Thanks!

 

I just got back from a test drive and I think everything is good again, except the warning light still is lit, does that mean anything, will it go away eventually?

I took your advice Quintin and it worked great! I did the following:

1. Took a blow gun to the whole engine and blew off everything around the areas you indicated. (though I did leave the coils on and didn't unbolt anything, just left it as-is)

2. Sprayed lubricant fluid all over the wires, everywhere that might have gotten wet I sprayed down, especially around the areas you pointed out near the plug wells.

3. Repeated step 1.

4. Test drove, all seemed great. No misfires, plenty of power climbing hills, etc... Now if I could just make the check engine light disappear I'd feel fine again. I'll never spray down an engine again with my pressure washer, thats for sure.

Thanks Quintin!

 

Your check engine light should go out and stay out after 3 heat/cool down cycles.....and are you sure a 98 has COP's? (perhaps the 98 5.4 had COP's?) I had a 98 Explorer with the 5.0 and it did not have coil on plugs - but had regular plug wires.....plug wires don't generally take very well to getting wet and can arc/short out for several days causing engine misfires and the CEL to come on. Sounds like you are good to go now and Ford does actually recommend that you spray down the engine from time to time - but be sure to check out your OM for what components to cover and a "gentle" rinse is all you should need....I'd stay away from power washing an engine and NEVER wash an engine while it is running (can cause water to be sucked into bearings, etc.) and never spray down a hot engine.....and alwasy cover the Master cylinder with plastic as the cap is atmospheric vented and you can get water into the brake fluid and cause "spongy" brake pedal feel..

 

use compressed air and a towel to wipe off the plug wire boots but sounds like u just got water down in the plug holes no big deal happens to me everytime we get a big rain. but i put some dialectric grease down in the boot to keep any water out and so far so good..

 

All years of 5.4L engines have COP ignition.

 

Last night I thought I had it fixed, but this morning on my 30minute commute it happened again, but it wasn't nearly as bad as it was yesterday and only happened sometimes when accelerating around 40mph. The truck is acting much better though than yesterday and the chugging wasn't nearly so bad today.

Should I respray it with WD40 tonight and then blow it with my air compressor again? Or will it eventually just dry out after a couple days? Also, is there anything more effective than WD40 for this purpose? The sparkplugs are on top of the engine buried under other coils and stuff and they look hard to remove (so do the coils towards the back) so I'm hoping I don't have to pull them out...

Thanks,
Matt

 

The first thing you should do now is to cruise over to Autozone (or similar) and get your ODBII code read. Don't listen to what the shop dude wants to sell you, just get the code and list it here.

Fritz

 

Since you have a '98 you might want to consider killing two birds with one stone and get a tune up if you haven't already done so (since you don't feel comfortable working on it). They (COP's) can be a real pain the first couple of times but not to bad afterwards. You probably have a little water trapped under the silicone boot in the plug well as mentioned before and the only way to eliminate the water is to pull the coils and blow them out or wait until they eventually dry themselves. Hopefully you don't short out a coil or you'll have to replace it (them).

Good Luck

 

One thing I have learned from others...Never wash an engine! Get a damp rag and wipe what you want clean. I know a fella just last week did the same thing you did. You are lucky, his would not crank when finished. Never would crank. Had to call a tow truck to pull into dealearship. Last I heard he was looking at a $300+ bill and it was growing....Ouch!

Best thing I can suggest is open the hood on these hot summer days. Park in the sun and let that baby dry. Also you can disconnect the negative side of the battery, let it sit a few minutes. That will clear the computer and give it a fresh start on your trouble codes........

Theres a bunch of sensors, etc you can ruin with water.