about 3 weeks ago there was a storm of Biblical magnatude here. Several cars were stalled in the water downtown which was up to the bottom of my doors and was IN their doors so I did my civic duty and pulled the less fortunate to safety with my brute. She ran great all day, I pulled about 10 cars out of the water to dry land and sometimes I could hear my cooling fan dragging in the water. So everyone is safe now and maybe my good deed is recorded in the book of life. Problem is, halfway to work the next day she started to buck and I didn't think I was going to make it home that afternoon, the check engine light came on that afternoon but I stupidly cleared it before looking at the code trying to inspect everything for water intrusion after I limped it home. I found NO evidence of water intrusion in any of the fuse boxes under the hood or anywhere else including the air filter/intake. No wires were undone either. I took it to my usual repair shop but they said they couldn't do anything with it because it is a 5.4 and they can't put their tester on the coil packs to see which one isn't firing, so I drove it back home. After two days it improved vastly, now it just misses under load(or seems to anyway) it may miss all the time it's just you are so isolated from the drivetrain in these trucks it takes a bug bump to notice it. It seems to accelerate as well as ever but up a hill on O/D it bucks bad. It has not lit the check engine light again though, which is what I've been waiting for. I've driven it everyday for the last 3 weeks and it hasn't got better or worse. I don't understand it, looking for advise. Should I just take it to the dealer, do you think they would have a way of diagnosing it? Maybe a "Ford dealer only" diagnostic tool of some sort? Thanks in advance for any help.

Here is waht I know for sure.
1. No water got into the engine
2. there is no water in the oil
3. the engine does not blow steam
4. it does not smoke or rattle
5. I'm not loosing coolant

 

5.4L=Coil Over Plugs

It doesn't take a lot of water to make the 5.4L engine misfire. You'll need to pull the coil off each of the plugs, remove any water (Brakleen in the red can works well) and then apply plenty of dielectric grease around the end of the boot. You should be able to reach all except the #4 coil without too much trouble.

 

Definately use ALOT of the grease; the combination of the high-energy sparks and water-retentive design make this a must (know from experience). Ford sells a large tube of the stuff; most auto stores will hand you a little tube and it won't be enough to do the job. Good luck!

 

so do I need to remove the fuel rail to get the coil packs off? I guess it would be a good idea to change the plugs (56K) while I'm at it? Has this exact thing happened to you guys too?

 

No need to remove the fuel rail.
The only real bear on my 2000 5.4 is getting the coil off #7. If I had a 1/4 swivel I am sure I could get that one with other than a 7mm wrench.


As far as the plugs go all down the passenger side. They look tougher than they are. All I have to do on mine is pull the injector wires along with the coil pack wires. I take the pvc out and get that side cleaned up a bit and once I have all the coil packs off I just use my swivel head ratchet with one 6 inch extension to get to #3 & #4. I of course got one of those longer Snapon plug sockets. If you are using a regular spark plug socket you may have some problems getting the new plug in tight.

After the first time of changing I have it down to 45 minutes start to finish on the plug change. That usually includes a beer or two to loosen up after hanging over the front of the truck down the right side.


Hope this helps
tom

 

it is now fixed. Thanks for your help guys. I did what you guys suggested. I didn't find any water in any of the coils or the plug holes, but I took them all out, cleaned them with brakcleen, gobbed some die-electric greese from Ford on them, replaced the plugs and viola! It was a PITA but worth it.