So i have a 2000 F150 5.4l with 76000 miles on it and i recently had the number 7 spark plug blow out. $500 later got it fixed and it has missed since then. Somedays its not bad other days its horrible... i dont know what to do, ive changed plugs, coil packs, ran fuel cleaner through it, and the seafoam stuff. Recently i have cleared the misfire codes and it still runs like crap but wont code it. At high RPMs it starts to shudder and the Service Engine Soon light flashes a couple times but then eventually goes off. Ill take any help i can get!
Thanks,
Jeremy

 

Hey this happened to me what did you use this happened on the motor craft they said it was only the one plug but i replaced them all again but with the champions they did the labor for free since it was just done but i did have to pay for the plugs

 

I replaced all of them with the Bosch platinums and i tried a couple others in the number 7 cylinder but nothing seems to help...

 

Remove the Bosch Platinums.

Install Motorcraft plugs .

Jump on eBay, purchase COP's ( 8 or 10 set) from Global auto or Uneek Supply. (NOT coil pacs- 5.4L's do not use coil pacs).

Install coils.

She'll be runnin like she should.

If you need help with the install, just ask once you get the parts, -we'll help yuh.

 

X2 on this advice.
If your in a hurry, run to your local NAPA and purchase a new COP (coil over/on plug) for $58.00 and get a new MotorCraft plug in there. If you haven't already, order a set of COP's from Ebay and replace all of the COP's as soon as you can. I would replace the Bosch's with MC's when you do the change.

 

Just re-read your post, just for the heck of it, check your voltage coming out of the supply plug to that #7 coil and make sure it matches the voltage in the #5 and/or #6 coil.

 

cool thanks guys, ill try the new coils and plugs. But unfortunately napa just closed so it will have to wait... Is there anything else i can do in the mean time? The Mechanic that replaced the blown out plug said that it could be a piece of aluminum causing low compression, thus a misfire. Is there anything i can do to take care of this????

 

UGGGG!!!!!!!!!!.....I really hope the mechanic used a bore scope and looked into that #7 cyclinder after he did the repair. The other thing he shoud have done is left the plug out of the #7 cylinder and tried starting it, to "possibly" blow out any debris that may have been in that cyclinder after his repair.
Did he use a heli-coil to repair that cyclinder. Find out what he did to inspect and remove any possible aluminum shavings after the repair on that cyclinder. Your mechanic needs to check compression on that cylinder before you go throwing parts at it.

 

My thoughts exactly, Im not sure what he used or did to get the shavings out of there... I know he used a steel insert with a plug to keep it from unthreading. When i brought it back to him (because of the misfire) he ran a compression test and said that cylinder was low, but just to drive it and eventually the aluminum that was stuck in their would blow it self out the exhaust.... That was over a month ago so im guessing that it has to be something else... But What???

 

dont get all tensed up just yet. just swap the #7 coil with the #6 coil and see if the misfire moves. when the plug blew out did the coil blow off the mount? maybe it screwed up the harness connector to the coil. and for the cop's just type in dg508 in the ebay search bar. and make sure you torque the new motorcraft plugs to 28 ftlbs. and just in case #7 is the 2nd cylinder from the very back on the driver side. with that said, did you change the plug/coil for cylinder 7?

 

I tried switching the coils between 6 and 7 and number 6 and 7 would code misfire... When the plug blew out originally the coil stayed screwed down to the heads.. So i know i have a bad coil on seven, im going to go to napa today and replace it which should help. But why would the number 7 still code with a different cop?

 

if the coil you placed in the #7 spot was good then the coil isnt the problem. what brand plugs do you currently have in the engine? is it still bosch? with a good coil on #7 you could do as tjk said and check the voltage to and from the coil. and the same thing with the injector. and just an fyi, if that mechanic used a helicoil, he may have screwed a valve(view pic in the link below). and may i ask what the exact code was? was it the p0307? or was it a circuit fault code?
clearances are very tight on the modular engines.
http://www.blownoutsparkplug.com/images/100_8593.JPG

 

I still have the Bosch's in it now, i just picked up a new cop and plug due to a crack in the side of the coil in number 7, i gonna try and check the voltage today. If this doesnt fix it im beginning to think that the mechanic screwed my valves up.... i really hope thats not the case. and it was coding a P0307.

 

When you pull #7 plug, take a look in there with a borescope and also do a compression test. You have to compare the compression to the other cylinders to do it right.

 

Hey Matt,
Is that Tap clearing the valve. From the picture angle, it looks like it is hitting the edge of the valve. Do you have the written article that goes with that picture that I could read.
Thanks,
TJK