Hello all, new here. I need major help. In the past 3 months my Excursion V10 has been falling apart! First it spit out cylinder 6 spark plug. I took it to a trusted shop who i know the owner personaly. They helicoiled a new set of threads into it. Next i had 2 coils go bad, so I replaced the entire set with OEM. Next I had cylinder 8 plug blow out. On the way to the UP this past weekend I lost a ton of power and the truck barely ran. I had a miss on 1,6,9 cylinders. I again replaced the coils and 1,9 cleared but 6 is still missing real bad! I took it to a shop there in the UP and they put it on the big scanner. It showed 6 has major miss. they pulled the sparkplug, and the entire end of the plug was disinegrated. He was an ASC certified mechanic, as well as a Ford certified mechanic, and seemed to know about the common Ford defects as he had also experience many of them himself with his own F250 V10. At this point he scratched his head and said "this is a new problem, i have not yet encountered". He installed a new plug, and retested everything but still a heavy miss! Coils all test good, injectors all test good and all coils have new boots. What are we missing here. He took a stab at it and said burnt valves..?? Any advise?

 

Maybe a bad connection on the wiring harness to the COP. Those little plastic clips tend to break, especially after a plug shot out. I've heard securing it with a zip tie helps. Good luck.

 

thanks for the tip....but... it seems very secure. the clip snaps right back onto it and it is reading a spark on the scope. im also not sure that lack of spark would cause it to eat the plug like that.

 

im ready to just pull this engine and replace it with a new one!! I love the truck over all but this 6.8 and all its known problems is just simply becoming not worth it. Does anyone know of any company that manufactures a 6.8 that has all the defects fixed and is more reliable?? I would obviously like to simply repair my current engine but its getting old quick!

 

Sorry to hear about your problems . I did not see the year of your Excursion or how many miles on the clock ,or if the spark plugs were ever been changed before .

You may want to do some search at this website about how to repair blown out spark plugs as there are few different methods . If memory serves well, the Helicoil was not a succesful V-10 engine thread repair method . Helicoil was not suitable thread repair for "tapered spark plug holes" . I recall instances that some of the forum members had recurring blown out issues with Helicoil ( hope you do not experience that ) . It appears that most satisfied members used " Timesert" inserts . Also a company called "blownoutsparkplugs.com" has successful repairs with their own proprietery method . It also worths mentioning that Ford Motor Co . supports a different method called "Fulltorque" method . You may want to get yourself familiar with all these methods , especially with Timesert method which would be my choice . Good luck .

 

The Helicoil was the first mistake. I suspect that the mechanic either let some metal get into the cylinder, and then it got stuck on the exhaust valve seat/face or punctured/cracked a piston, or somehow the depth of the plug is wrong and it either contacted the piston, or somehow it ran superlean and ate itself.

Replacing COPs all at once, twice, well, that's just throwing good money after bad.

The only times we've ever heard of multiple plug blowouts was when they were replaced by a bad mechanic, or there was some substantial corrosion issue because they were never EVER touched.

I would certainly check the compression on that cylinder, at the very least, and myself would certainly do it on all cylinders.

Something is amiss... pun intended.

 

I have about the same problem on #4......the plug blew out...a shop put n insert in and still had a miss. Tried new coil..plug...still a miss......a shop just checked everything over.....only 40Lbs on #4. Now its time for a new valve. Some say....either pull the motor or pull the cab off. Anybody know if the head can come off without doing either??

 

Thank you for the replys!! To answer a few of the questions, it is an 01 Excursion v10. It has 140,000 on it, and has always been driven easy and well maintained! Not a spot of rust nor a rip in the leather. The plug in #6 and coil were new due to the blow out. It ran absolutely perfect for about a month/ 1,000 miles, after the helicoil job the shop did. I was just re-connected with a old friend's dad who is a 30+ year Ford mechanic and he says he knows all about this issue, so im gonna drop it off by him and see whats up. Wish me luck!

 

So much for the luck. I spoke to him on the phone and he said either way im screwed. Needs a new motor wether it be a valve or a piston or what... Its shot. Im gonna drive it on 9 until it locks up then weigh my options. Seriously dissapointed in Ford for not recalling this motor after all the known issues it has! Its number 2 on the biggest mistake list And thats a bummer cause i love this damn truck!

 

If I were you , I would talk to a shop with experience with Timesert inserts or call "blownoutsparkplugs.com" see if they can help you .They resolved numerous sparkplug related problems without removing engines or heads .

Good luck