Hello, I am a new member here. In April I bought a 07 F150, 5.4 w/ 18k miles. within the first week it developed a misfire...no big deal, I took it down to the dealer and they replaced #4 cop and spark plug. Less than two weeks later same thing ...back to the dealer and again #4 only this trime we just had to replace the plug. Less than two weeks later #6 cop and spark plug, well now I have a misfire again. What is going on! This truck was a "factory truck" and it looks like it may have sat for awhile, the cam covers have some light oxidation on them. I told the dealer that I wanted all cop and plugs changed because I don't have time to go there every other week to have my truck serviced. Anyone else have this much trouble? Any insight, suggestions or comments would be appreciated.

Tom

 

have you or anyone else cleaned the engine? do you get alot of rain? or snow? do any mudding? how long have you owned it?

 

I bought it in April this year. I have never cleaned the engine (Iv'e been told by the Ford Tech to NEVER clean your engine.) I do not go muddin with it. I live in PA so we don't get excessive amounts of rain.
Tom

 

well its either just your luck or theres water or something down in the plug bores. just keep us posted if you have problems after they change your coils and plugs. i'm sure they are gonna charge you for the coils. so i'd get a full set of 8 or you can get the v10 package off of ebay through global or uneek. they sell the set of 8 for 135bucks or 10 for 190 bucks and have a couple spare coils vs. 70 bucks per coil from aftermarket suppliers and alot more for motorcraft. just type in dg511. then you can have the dealer change them and the plugs for much less. whats the build date on the truck? late 07 had a change in head design and spark plug design so they dont stick anymore. it makes a difference in the plug change cost and whether you can use those coils or not. what color are your coil boots? that'll helps us as well.

 

Actually I think its dg511's that are needed for o4-o7 trucks and midway through 07 I think they changed them again so if the boots are brown you need the 07-09 coils that I dont know the number for.

 

yup. i corrected my post. sorry bout that.

 

Wonder if some DA shop gopher did an engine bay cleanup and got a little too liberal with the water. That's what happened to my buddy's 05 lariat when he bought from a non Ford used car lot. We chased miss fires for a month because of that. Ended up replacing all the cops and boots. After a year now still hasn't had a problem.

 

how are yall getting problems from washing the engine? i pressure wash mine everyweek and get it very good in all of the little nooks and havent had a problem out of it yet. ive even takin and sprayed it with engine brite and then flooded the engine with a water hose and no problems.

 

???????????
Really?
Any of the motors with the COP setups are vulnerable to water settling into the recesses where the plugs and COP boots are. This causes the miss fires. If you have been doing this on one of these motors you have been lucky.

 

jrfonte,
Power washing the engine can force water under the coil boot and fill the plug well with water. This leads to a short circuit and the plug misfires. Your garden hose may not produce enough pressure to get under the boot so you are safe.

.

 

did you not see that? i do pressure wash it with a 4000 psi pressure washer much higher than any car wash facility around here but have never had a problem out of it. i wash the 5.4 just like i have all of my vehicles engines to keep them clean.

 

Yea i pressure wash my engine atleast once a month and have never had a problem.

 

i had the same problem with my truck. i just changed the plugs

 

Interesting?
People who pressure wash and NO problems.
People who pressure wash and DO have problems.
Must be the technique?
Or they must have good COP boots.

 

maybe, maybe not
i have put the tip of the pressure washer right on the boots before to clean out the dirt around them.
this thread is the first i have ever heard of the cop pressure washing problem but i dont come to this part of the forum very often either.