P0307 #7 misfire

[megan4221977]

Well did compression test.. checked #5-7 cylinders, 8 is hard for my short self to get to… all were the same 150psi… so that’s a good thing! Waiting on gaskets for valve covers now, none in stock around me so had to order

 

[Frank Swygert]

I'd switch too. Could first, and if the misfire doesn't follow the coil I'd just get a new plug. They aren't costly but hard enough to get to that I wouldn't want to change two. Hope they are all easier to get to than on my 2005!

 

[megan4221977]

Yeah I forgot to put mine 2011 Ford Expedition 5.4l 3v… has 20inch rims and I’m short!! I have a step ladder!! lol waiting on valve cover gaskets to put back together, before starting back up

 

[Dustin Gebhardt]

As Trainmaster said, you may want to check the connector for the COP. The rubber o-rings on mine were falling apart, which prevented them from making a good connection to the COP. I replaced all 8 of mine and haven't had an issue since then with misfires.

You moved the COPs around and the issue stayed with #7. You changed the plugs and the issue stayed with #7. It doesn't appear to be related to the plugs nor COPs themselves. That leaves the cylinder, but the compression test came back good. A broken roller follower could cause this misfire, but you said that it looks fine, too. So that eliminates most of the mechanical items. I'd check the COP connector next. Here are the ones that I bought:

ignition pigtails

 

[megan4221977]

@ Dustin TY… as soon as at get gaskets, tmw, and get back together I’ll check those

 

[Texas Dave]

I know this is going to sound crazy...but I had the same exact issues with my 2007. I tried replacing coils and plugs and still had the problem. Someone told me to replace the gas cap. I did and the problem went away. I can stomp it to pass someone on the highway and it runs smooth and strong. Fortunately, in my situation, this was a cheap and easy fix.

 

[Planocat]

I feel your pain....experienced exact same issue on my 5.4L 3V. Literally spent thousands from the local mechanics parts cannon to no avail. I loved the truck and have it setup and accessorized just the way I wanted it. Being a stubborn old fart in my 70's, I wanted it to be my last truck. Boy, did I pay the price for that. I'm attaching a list from the parts cannon (please, no "what a ********" comments. I know, I know.

Resolution was reached by a young service writer at major Ford dealership during oil change discussion when he said..."Maybe you need a new set of eyes looking for the problem, we have couple of great techs and the equipment sophisticated enough to diagnose anything". I went home and thought about it. Came to the conclusion I had spent years and thousands to no avail. Made appointment with his Master Tech who was a couple of weeks out.

Received a call next day that he had it fixed but wanted permission to drive it home and back (about 150 miles) to be sure. Picked it up about 2 years and 45K ago and haven't seen the dreaded check engine light / misfire since. Had I taken it there in the first place, I wouldn't be writing this. But then I wouldn't have a truck where everything should be "good to go" for the next 230K. I attribute the cure to a very high dollar diagnostic machine and a great tech who was very conscientious and knew how to use it!

Here is the list of what was done BEFORE I brought it to the dealer. No one likes to spend $160 an hour labor, but it would have saved lots of money and heartache.

Hope this helps......



Maybe it's time for a new set of eyes on your vehicle.

Best of luck......
Planocat

 

[megan4221977]

@Planocat what was the issue he fixed?

 

[megan4221977]

@TexasDave doesn’t have a gas cap wish it was that simple

 

[Planocat]

At the end of the day, I think I received counterfeit coils and plugs off the internet from Walmart.com. Fordmakuloco has a youtube video on Motorcraft counterfeit parts and I believe that I was the victim as the whole issue started when I replaced all 8 plugs and coils with "genuine Motorcraft" parts not purchased directly from Ford. That all started the witch hunt for the vacuum leak, fuel pressure, etc. cause.

In addition, looking at the final cure from the dealership, that appears to be 2 coils and 2 plugs, I do not minimize the EEC diagnosis, Pinpoint Tests, and especially the update of the PCM. All I know is that at 231,000 miles it is the strongest running vehicle I own and hasn't missed a beat since Jan 2020.