Dirttracker18

So to carry on here, IF the tireman used non-motorcraft plugs, which is extremely likely, that could be the issue right there. Most non-motorcraft plugs do not last in our engines. Not sure why that is. The most popular replacement was the Champions and they are well known to start causing issues early.

Secondly, and far more importantly, doing any work without a full diagnosis is a recipe for disaster. Let me explain.

You had a miss or misses and went ahead and had the plugs changed. The true issue MAY have been a weak coil. This may or may not show up easily but what a weak coil will do is take out a sparkplug. With that in mind, by changing plugs and not ruling out a coil or coils you may have taken out a plug or plugs due to a weak coil still being in place.

This is why a proper diagnosis is crucial but often overlooked causing further unexplained issues down the road.

This is why I have suggested early that you can either toss parts at it and hope for the best or pay some money and have the issue diagnosed correctly.

Ask around your area, using forums for car clubs in your area can help, and find a really good mechanic that is known for his/her diagnostic skills. I have a few that I turn to when I am stumped or need clarification. I will gladly pay their full hourly rate for an hour or two of time well spent.

SamMcClurg

The first time I went to the dealer, they said it was the spark plugs and then when i told them that they were 14k miles old they said "well that rules out the spark plugs..so its the coils" and then the second trip, after i showed them what it was doing, they had the transmission guy go drive it and he gets out and said immediately he was positive it was spark plugs. then they ended up changing a loose spark plug and two bad coils and the problem was still not fixed. I have replaced all of the coils they didn't touch and problem still remains.. only thing left out of the options they thought are one or all 6 plugs they didn't change.

Summers22

iTrader: (2)

What brand of coils did you use?

SamMcClurg

The dealer used motocraft for 3 of them but the other 5 I put in are duralast. They have a lifetime warranty at autozone and I read some good things about them

Summers22

iTrader: (2)

I understand that.....but you are still having mis-fires. All that needed done with the original OEM coils is boots and springs. Coils rarely fail. I have yet to have one fail in 400k plus miles of having COP equipped Fords. If it were me and I was tired of chasing this problem, I would put in 8 new Motorcraft coils and 8 new Motorcraft sparkplugs. $400 in parts and 2 hours in your driveway. Done.

See links below, $357 to be exact.

Summers22

iTrader: (2)

If you have the 5.4:

http://www.ebay.com/itm/SET-OF-8-OEM...xX857Q&vxp=mtr

http://www.ebay.com/itm/MOTORCRAFT-I...JXhUZj&vxp=mtr

SamMcClurg

The plan is to change all the spark plugs next week when I have time. The transmission mechanic at the dealer drove it and he stepped out and immediately said it was a spark plug and that it wasn't the transmission. Also got another opinion from a respected mechanic and he thought at first torque converter and then I told him about having a loose plug and then his mind changed to possible cracked spark plug. It's possible that the tireman did not put all of them in well obviously since one was loose. I don't personally feel it's transmission because I don't have problems shifting or issues like that, but hell I know very basic things so all I can do is guess until I fix it for now

Summers22

iTrader: (2)

Well many people mistake a transmission issue for a mis-fire. I have seen it numerous times on this forum alone.

txjessicalynntx

Mine (2006) did this, I replaced all spark plugs and ignition coils (did it myself $220) and it quit doing it. When it was plugged up cylinders 2,4,6 and a random were missin bad...so I just replaced everything. Might as well.

A buddy of mine has an older model than mine (2004) his truck had the same issue but his turned out to be the transmission...

bigmac712

It is frustrating talking to any of the service dept reps. I went to my dealers service department and asked them if I could talk to a professional Ford mechanic to discuss the probability of what causes the bucking when only in O.D. between 1200 and 1700 rpm's (roughly 40 to 55 mph) on a slight load going up a slight grade. They look like they all have dark hollow pools for eyes when I explain to them and all they do is guess. When I asked the rep if I could talk to a pro tranny mechanic first he just stood there insinuating that he was the pro and all I got was guess work. I like to have a conversation first with a professional mechanic that actually knows about diagnosticing probability before I plug it into their diagnostic equipment. I've gone in for a $70 job and walked out costing $400 and sometimes more. Anyway, it doesn't do it when I disengage the O.D. no mater what low RPM's I'm still am turning same 1000 to 1700 RPM's. Motor runs very strong, has no real noticeable engine skips. Idles fairly smooth. I had the plugs replaced back around 86,000 miles. Trucks got 126,000 miles now. I did have a transmission O.D. switch replaced, probably a couple of years ago, when it couldn't make up its mind to stay in O.D. I had that fuel module replaced that's attached to the frame back by the rear axle one time when I encountered a skip while driving along back then too. That was a couple of years ago too. The injectors have been checked around that time too and no problems with them, YET. I've purchased a couple of those engine diagnostic tools back then that couldn't find any codes to tell me what needs to be fixed or replaced. Brought them back. Right now I just want to find somebody that has experienced a similar problem that might shed some light on this problem before I commit to being highway robbed at the dealer.