Hey all,

I have a 2006 Lincoln Mark LT (an F150 with a 5.4 V8 in pretty much every way that matters except looks), with 69,xxx miles. I'm covered by an extended powertrain warranty until February/75k miles.

I have a few powertrain mods:

SCT X3 programmer with custom tunes by Stang Hi Performance in Baton Rouge, adjusted for tire revs per mile
MBRP cat-back exhaust
DWV air filter mod with K&N drop in filter
Aeroforce interceptor digital gauge
33" tires, stock 3.73 gears

I have a strange (to me) issue that started last Wednesday, December 19:

I was driving home from my camp, (running my 93 octane tune with Exxon 93 octane gas) on the interstate and passing another vehicle. At this point I was in second gear at WOT (auto tranny, in drive) and ran all the way up to 85ish mph at about 5100-5200 rpm. The 2-3 upshift felt especially rough to me, and my check engine light began flashing. I slowed down and pulled off on the next exit and into the nearest gas station.

With my programmer, I read the DTC codes, and ended up with a P0301 code, a cylinder 1 misfire. My initial thought was to clear the code, restart the truck, and see if the misfire stopped. It didn't. Extremely rough idle, etc.: the usual symptoms of a misfire.

Called my dad to let him know (technically his truck), and he decided we would tow it to the nearest dealership. At this point, I had googled a few things and had made my predictions about what needed to be replaced (as I usually do whenever things break on any of our cars). I thought it would be the ignition coil, spark plug, or fuel injector.

I retuned the truck back to stock configuration so the dealer wouldn't automatically say "well of course it was the programmer!".

Over the next two days, the dealership performed all the easy tests (compression, plug, coil, injector, etc.). Everything looked fine, but there was still a miss. They replaced the plug, coil and injector for good measure. At this point, they decided to pull the valve cover after the holidays and check for a bent valve or a damaged camshaft or anything else out of place.

The dealership reopened for the holidays today (December 26), and their diagnosis as of today is a bad PCM. I haven't actually spoken with the service department, but my dad told me they had called him to let him know that they had pulled the valve covers and the headers and that was about all he could remember. Everything looked fine to them, but the truck still had that misfire.

So I have a few questions:

1. Does a faulty PCM sound like a probable cause of this misfire? I would assume they would have checked for bad wiring before ordering a new engine computer, but you never know...

2. I know from doing a few searches that I will need to bring them both of my keys for them to set up the new PCM. Anything else I need to know about how this process will work?

3. Will my programmer still work? Meaning, will I be able to just plug it in and tune to my 93 octane tune with the new computer, or will I have to bring the programmer back to the tuners that set it up?

Any ideas or opinions would be greatly appreciated!

Thanks!

 

I had the same thing happen to me with my 06 Lariat with 79K miles and a new set of plugs .
It had been running great .
I have somewhat similar mods to my truck as you have to yours .
Same symptoms / circumstances and same code except number 8 cylinder.
When I changed the plugs I did not change the COP's .
I ordered a new set of COP's from Global on eBay and replaced the number 8 COP .
Problem solved .
I haven't gotten around to replacing the other seven yet , but I will once it stops raining here in the Pacific Northwest .
I would think twice about the new PCM from the dealer .

 

Thanks for the response. When the issue first appeared I initially thought that the coil might be cracked or corroded or something of the like. The dealer apparently replaced the coil, plug, and injector on that cylinder with new and verified factory replacements, but they found no change in the problem.

Given that the truck is still under warranty, the new PCM will be covered and I won't owe anything besides the diagnostic fee that I would owe anyway.

That being said, I'm hesitant to believe that the computer itself is faulty...I think I would have seen some issue before it just stopped firing a cylinder (but maybe I'm wrong about that). I didn't have a chance to check the wiring going to the coil and injector myself, but I hope the dealer checked the continuity of those wires before they jumped to the conclusion of a faulty PCM.

This is actually a different dealer than I typically use (so I have no prior experience with the service department); a. it was the closest dealer to me when the misfire began, and b. my usual dealer doesn't allow vehicle drop-off at night.

 

I just heard from the dealer; they got the new PCM on Monday, installed it yesterday and tested today, but the truck still has the same misfire. I'm at a loss for what the problem could be at this point. If I remember correctly, the dealer said a rep from the Ford factory is coming out to look at the truck. Never heard of that before.

 

[QUOTE=njedwardz;4941049]I just heard from the dealer; they got the new PCM on Monday, installed it yesterday and tested today, but the truck still has the same misfire. I'm at a loss for what the problem could be at this point. If I remember correctly, the dealer said a rep from the Ford factory is coming out to look at the truck. Never heard of that before.[/QUOTE

There are several people, myself included, chasing the same problem. From what I can tell, it seems to be the plug, wires and/or COPS. I think I'm going to replace my COPS once I figure out how to do it! Most people have solved it that way.

 

X2 for rando 60k on mine plugs failed. I changed the cops while I had them off runs like new.

 

Yesterday we told the dealership that we would like to have the truck towed to the larger dealership in the area, and the mechanic we talked to seemed to think that was a good idea. We plan to have it towed tomorrow afternoon.

The owner of the dealership (the one that it will be towed FROM) called tonight and informed us that they had found that the issue was present only under 1100 RPM and that they think there is a cam timing issue (I didn't talk to him, my father did, so I can't quote exactly what he said the problem was).

Now, I know these engines have some type of cam phaser tick issue (haven't researched it yet), but does a timing issue seem like a plausible cause of a misfire under selective RPM conditions? And what could cause the issue to appear spontaneously?

BTW, they haven't said anything about charging us for anything yet. When we suggested towing it, the mechanic said they were willing to forget they had ever worked on the truck and just foot the entire bill...

 

Well if it is an rpm related miss, that would be easy to verify by driving around and testing under real conditions. That's a weird one.

In my case, completing the 200k tune up, the new plugs, coils and wires eliminated my miss. The truck now runs unbelievably better, like it only has 100k on it!

On the lighter side it's good to hear even professional mechanics struggle with some problems.

If it was me, I would press the issue hard while it's under warranty to get it resolved. I would think you could research the cam timing issue. I would seem plausible it could be rpm related but the details would be interesting.

 

From the very, very small amount that I've read, I think a cam issue would cause a misfire on more than just one cylinder in that bank.

The dealer is supposed to call today and let us know whether or not they want to have it towed elsewhere. From what I understand, cam timing work is a fairly involved process.

 

Alright, talked to the dealer and they said they are done trying to fix it and referred us to another shop. We don't owe them any money or anything at this point. I picked up the truck today and I'm fairly certain it's running worse than before. Maybe it hasn't learned a new idle yet or something.

The engine still has a dead miss on cylinder 1. The shop it was at did not pull the front cover, but they suspect a cam phaser issue. When I got the truck home, I gave the motor a listen with the hood open and I can definitely hear a ticking noise of some kind.

The truck is scheduled to go to the next dealer on Wednesday.

The truck drove fine (not well, though) on the interstate on the way home, but it's hilariously down on power from where I remember it being. It's staying in the garage until the dealer appointment on Wednesday.

Anyone ever heard of a phaser issue causing a misfire on one cylinder? Or a single missing because of any kind of timing issue?

Considering they've replaced the coil, plug, injector on that cylinder, the PCM on the truck, and pulled the valve cover and inspected everything in there, I would think (from my limited knowledge of this engine) that the only issues left would be inside that front cover of the engine.

Let me know of any other ideas or potential issues...

Edit: Link to a video of what I hear:

 

spark plug or injector. A cam phaser/solenoid issue will affect all cylinders on that bank.

 

I'm inclined to agree with you that that's a more likely explanation, except that they replaced all 8 plugs, swapped coils and injectors between 1 and 2 with no effect, and even replaced the full PCM.

As I haven't done any of the testing myself and don't have the equipment to do so, I have to take the dealer's word that they did everything I've listed, including compression testing. Apparently they pulled the valve cover and there weren't any issues there either.

I guess I'll find out next week (hopefully) when the truck goes to the next dealer.

 

I took the truck out for a drive today, and today I heard a sound that I had not noticed before. Here's a link to a video of the sound:


The video starts ar 900 or so RPM. This sound is present at ~750-1000RPM. I've done some reading and this sounds like a VCT solenoid noise.

Any new ideas?

 

The VCT solenoid on the drivers side of my truck starting acting up this week, threw the P0012 code. It doesn't make any noises like that but it has made it idle a lot rougher than normal also affecting power and mpg.

I am going to pull it as well as the passenger side solenoid out, clean them both and reinstall in opposite sides. That way if the code switches to P022, I'll know it's that solenoid for sure and not the phaser (again).

Could a cracked manifold or stuck lifter potentially have the same symptoms?

 

Im having the same problem exept a misfire on #4. Its got all new plugs and coils they have taken off valve corvers and inspected all was good said they think its a bad wire going to #4 or computer they give up and said to take to a dealership.

At this point the other shop had already cleared codes and the dealership put 420 miles on the truck and could'nt get it to act up or get a CEL. So i pick it up and get a CEL for them at WOT, while i had it i cleaned MAF sensor and cleaned throttle body ( rough idle ) didnt help. Had the hood opened while running and heard the same ticking noise yours has. They call today and say its a cam phaser and timing issue im not sure what codes they got this time. They also said they probably would find a broken tensioner when they get it apart. Scheduled to work on it monday

I'll post back and let you know how it goes, sounds like their thinking along the same lines. Hope yours goes well!!