Triton V10 misfiring badly

[WileyOne]

I just heard from the Ford dealer in NC a few minutes ago.
They tell me I had one bad coil pack. After they changed it and cleared the codes, it drives nicely and no codes have reappeared. I'll drive the toad down there to retrieve it tonight.

Nobody has been able to explain how a bad coil on #7 can cause fault codes to appear on #3, #6, and #2, but that seems to be exactly what happened. I guess the lesson is that the codes can't be trusted. Nobody warned me about that. I still don't understand what is meant by a "companion cylinder".

And, here is something else nobody tells you. A support guy at 5-Star warned me that the "tune" can put additional stress on plugs and coil packs. I guess they boost the spark to make it a little hotter.

From now on, I plan to carry one or two spare coil packs wherever we go, just in case. They are the most common component to fail on a Triton V10, notorious for going bad, and simple to change without tools.

[ga traveler]

First, thank you for letting us know the outcome. Second, congratulations on such a simple fix. Some days you just get lucky. Let us know how it goes in next few weeks. I have never heard of a coil pack affecting other cylinders,but these new engines and computers can do some weird things. I just watched a video of a Cadillac stop
light coming on while driving. It was caused by a computer glitch. Who knew that stop lights were run through a computer.

[bigb56]

Diagnostic trouble codes do not always pinpoint the problem, they can be useful to a skilled mechanic in order to locate the problem but more often than not certain DTCs are symptoms of the underlying issue. Too many mechanics are just parts changers and will start changing good parts because the DTC says a part is reporting a problem but that part is not necessarily causing the problem, it is just reporting that something is wrong with the information it is receiving. A misfiring cylinder can cause all sorts of DTCs due to it causing the entire engine to run poorly and therefore other sensors will report that they are receiving out of range information resulting in a DTC. Hope this makes sense.

[SergioP]

Originally Posted by WileyOne

From now on, I plan to carry one or two spare coil packs wherever we go, just in case. They are the most common component to fail on a Triton V10, notorious for going bad, and simple to change without tools.

The only tool you need to change a coil is a 7mm socket, about a 4 inch extension and ratchet. Waiting for the engine to cool down enough to work on it is the main thing. Unless it’s one of the rear coils that are easy to access after removing the doghouse.

I carry a spare coil and spark plug just in case.

[WileyOne]

Originally Posted by SergioP

The only tool you need to change a coil is a 7mm socket, about a 4 inch extension and ratchet. Waiting for the engine to cool down enough to work on it is the main thing. Unless it’s one of the rear coils that are easy to access after removing the doghouse.
I carry a spare coil and spark plug just in case.

Oh! I haven't had to change one yet, but I now have one ready when that day comes.

So far, I've only watched others do it on YouTube.
What is the 7mm socket for? In the videos, it seemed like the wires just snap on and snap off. Is there a hold-down bracket in certain years?

The Ford Dealer charged me $380 to diagnose and replace that coil, which included the part. Does that seem high? I think they added a "we hate to work on RV's" surcharge and probably a "we had to unhitch your dolly" surcharge.

[SergioP]

There’s a one inch long small bolt that holds each coil down to the head.

[PbdBlue]

Originally Posted by WileyOne

Oh! I haven't had to change one yet, but I now have one ready when that day comes.

So far, I've only watched others do it on YouTube.
What is the 7mm socket for? In the videos, it seemed like the wires just snap on and snap off. Is there a hold-down bracket in certain years?

The Ford Dealer charged me $380 to diagnose and replace that coil, which included the part. Does that seem high? I think they added a "we hate to work on RV's" surcharge and probably a "we had to unhitch your dolly" surcharge.

Seems very reasonable to me. Surprisingly so for a dealer.

[Roy-c]

in our area dealer labor rates are around $125.00 per hour. If you figure an hour of diagnostic time, r & r doghouse and any other labor consuming stuff peculiar to an RV, add the parts and I think you were treated more than fairly.

[SergioP]

Originally Posted by Roy-c

in our area dealer labor rates are around $125.00 per hour. If you figure an hour of diagnostic time, r & r doghouse and any other labor consuming stuff peculiar to an RV, add the parts and I think you were treated more than fairly.

Right. Figure about $80 for an OEM coil, $130 for one hour of diag, then another 1.5 hours or so for access and replacement of the part.

[LETMGROW]

Originally Posted by WileyOne

I just heard from the Ford dealer in NC a few minutes ago.
They tell me I had one bad coil pack. After they changed it and cleared the codes, it drives nicely and no codes have reappeared. I'll drive the toad down there to retrieve it tonight.

Nobody has been able to explain how a bad coil on #7 can cause fault codes to appear on #3, #6, and #2, but that seems to be exactly what happened. I guess the lesson is that the codes can't be trusted. Nobody warned me about that. I still don't understand what is meant by a "companion cylinder".

Let me try to help you out a little here. Some of these computer controlled systems can and will shut other cylinders down intentionally by shutting off pulses to other cylinder injectors to shut the fuel off in those cylinders. This is to protect the engine from out of balance running which can lead to undue wear to mechanical parts. These engines will enter into what is called a "Limp Home" condition.
This is where a higher end computer scan tool capable of reading data is more valuable in the diagnosis than a simple code reader.
Once the misfiring cylinder condition is repaired the computer will automatically start firing the remaining cylinders and the engine will run normally.
I have seen "techs" replace as many as four coil packs because their cheap little code readers showed misfires on multiple cylinders. No doubt only one coil was bad.

[WileyOne]

Originally Posted by LETMGROW

Let me try to help you out a little here. Some of these computer controlled systems can and will shut other cylinders down intentionally by shutting off pulses to other cylinder injectors to shut the fuel off in those cylinders. This is to protect the engine from out of balance running which can lead to undue wear to mechanical parts. These engines will enter into what is called a "Limp Home" condition.
This is where a higher end computer scan tool capable of reading data is more valuable in the diagnosis than a simple code reader.
Once the misfiring cylinder condition is repaired the computer will automatically start firing the remaining cylinders and the engine will run normally.
I have seen "techs" replace as many as four coil packs because their cheap little code readers showed misfires on multiple cylinders. No doubt only one coil was bad.

Man, I really wish you had jumped in with this info when a back-woods ASE-certified truck mechanic was reaching under his John Deere cap to scratch his head on a holiday weekend. He was using an inferior scan tool and none of us had any idea that one bad COP could throw multiple codes. He tried changing one coil but I guess he was too lazy to check the others. With this new information, he might have found the coil that was actually bad and we could have continued our vacation. Instead, he gave up and had to "limp" our MH 50 miles to a Ford Dealer who refused to look at it for 5 days.

One thing is still bugging me. If the "limp home" feature is intended to prevent mechanical damage and pumping of unburned fuel, why in my case did it do the exact opposite? We now know that I had only one bad coil on #7, which the PCM misidentified as being on #3. At that point the engine was running near perfectly with no shake or shudder. We could have easily continued 300 miles to our destination.

But, then the PCM decided to forget about #3 and flag #2, #6, and #7, only one of which actually had a problem. Are you kidding me? I'm pretty sure all three of those cylinders were then shut down as you describe. Now, with only 6 or 7 cylinders working, the engine really did start to shake and shudder. I could barely pull a slight uphill grade.

Instead of the PCM diagnosing and mitigating the problem, it made the problem far worse. I had to cancel my vacation and who knows whether additional damage was done to my engine because of incompetent engineering. Shame on those Ford guys for that crappy implementation.

[LETMGROW]

Chances are the coil didn't go entirely dead for a while but was expiring gradually and becoming weaker as you were driving. The ECM needs to see a certain number of misfire counters before it will start shutting down other cylinders. Unfortunately no two systems always react exactly the same.

[Bobby F]

Originally Posted by LETMGROW

. . . spark plugs can become glazed from sitting for periods of time, drying out then being run again.

Interesting. I assume you mean some nonconductive deposition coats the metal and hinders spark. I've never heard of this before. Any info on what the material might be?