All cylinders misfiring
04-04-2013, 04:43 PM
#1
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All cylinders misfiring
Curious to what would cause all cylinders to misfire?? I took the truck into the dealership today to find out all the cylinders are misfiring, not throwing any codes. Its an 06 5.4. Just had all the plugs replaced last year. They are going to keep it over tonight to run more tests, but Im curious as what would cause all 8 to misfire.
04-04-2013, 07:55 PM
#2
im not sure how close my prediction will be but, on a "big rig", when all cylinders are misfiring it usually means an ecm reflash or replacement. i know diesels, its gasoline engines that screw with my head...haha
04-18-2013, 10:31 AM
#3
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Thought I would return with an update. The dealership kept the truck for three days with a resulting recommendation to replace the cats. When I asked how the cats would cause all cylinders to misfire, I really didn’t get a direct answer. I would also think if all 8 were misfiring, I would have other issues, except for the engine stutter when passing/accelerating hard. The engine runs great at all other times with never a check engine light coming on.
I took it to another mechanic this week for a second opinion; they think the problem is internal to rocker arms/rods. I tend to think that if this was the problem, as above, it would occur more often than just at hard accelerations. At this point I have received recommendations to change out the cats at $1,500 to a possible engine rebuild around $4K.
Next week I plan on taking it for a 3rd opinion at another local Ford dealership. Starting to get very frustrated!!!!
I took it to another mechanic this week for a second opinion; they think the problem is internal to rocker arms/rods. I tend to think that if this was the problem, as above, it would occur more often than just at hard accelerations. At this point I have received recommendations to change out the cats at $1,500 to a possible engine rebuild around $4K.
Next week I plan on taking it for a 3rd opinion at another local Ford dealership. Starting to get very frustrated!!!!
04-18-2013, 01:18 PM
#4
Give more details about when and it is doing,
How do you know they are all misfiring?
How many miles? Noisey?
Andy
How do you know they are all misfiring?
How many miles? Noisey?
Andy
04-18-2013, 01:37 PM
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The problem occurs during heavy acceleration, such as when I speed up to pass someone or entering the highway via an on ramp. It does not appear in normal accelerations, just when I gun it when Im already doing around 45MPH.
Its not to noisy. I think the second mechanic was hearing the noise from the Cam phaser Tick/ Knock issue (https://www.f150forum.com/f4/final-r...k-sound-141266). The noise is only noticeable when you have the hood popped and you’re close to the engine. It always had that tick.
As far as the misfiring, Ford mechanic said it showed from their diagnostic testing. The truck doesn’t misfire, idle rough, hesitate, anything at idle or low speeds. Not sure how diagnostics performed while the truck is at idle would show everything misfiring. Again, its not throwing any codes. But again, I certainly don’t know how the diagnostic testing computers fully work.
The truck has 135K miles. I got it at 70k. I haven’t changed out the fuel filter and from reading I tend to think the problem could lie there, or in the pump or FPDM.
Its not to noisy. I think the second mechanic was hearing the noise from the Cam phaser Tick/ Knock issue (https://www.f150forum.com/f4/final-r...k-sound-141266). The noise is only noticeable when you have the hood popped and you’re close to the engine. It always had that tick.
As far as the misfiring, Ford mechanic said it showed from their diagnostic testing. The truck doesn’t misfire, idle rough, hesitate, anything at idle or low speeds. Not sure how diagnostics performed while the truck is at idle would show everything misfiring. Again, its not throwing any codes. But again, I certainly don’t know how the diagnostic testing computers fully work.
The truck has 135K miles. I got it at 70k. I haven’t changed out the fuel filter and from reading I tend to think the problem could lie there, or in the pump or FPDM.
04-18-2013, 02:08 PM
#6
Originally Posted by tjones8611
The problem occurs during heavy acceleration, such as when I speed up to pass someone or entering the highway via an on ramp. It does not appear in normal accelerations, just when I gun it when Im already doing around 45MPH.
Its not to noisy. I think the second mechanic was hearing the noise from the Cam phaser Tick/ Knock issue (https://www.f150forum.com/f4/final-r...k-sound-141266). The noise is only noticeable when you have the hood popped and you’re close to the engine. It always had that tick.
As far as the misfiring, Ford mechanic said it showed from their diagnostic testing. The truck doesn’t misfire, idle rough, hesitate, anything at idle or low speeds. Not sure how diagnostics performed while the truck is at idle would show everything misfiring. Again, its not throwing any codes. But again, I certainly don’t know how the diagnostic testing computers fully work.
The truck has 135K miles. I got it at 70k. I haven’t changed out the fuel filter and from reading I tend to think the problem could lie there, or in the pump or FPDM.
Its not to noisy. I think the second mechanic was hearing the noise from the Cam phaser Tick/ Knock issue (https://www.f150forum.com/f4/final-r...k-sound-141266). The noise is only noticeable when you have the hood popped and you’re close to the engine. It always had that tick.
As far as the misfiring, Ford mechanic said it showed from their diagnostic testing. The truck doesn’t misfire, idle rough, hesitate, anything at idle or low speeds. Not sure how diagnostics performed while the truck is at idle would show everything misfiring. Again, its not throwing any codes. But again, I certainly don’t know how the diagnostic testing computers fully work.
The truck has 135K miles. I got it at 70k. I haven’t changed out the fuel filter and from reading I tend to think the problem could lie there, or in the pump or FPDM.
04-18-2013, 02:30 PM
#7
Your locking pin on one or both phasers has probably sheared off...This happened to me and threw out the entire LH bank. The phaser bolt is torqued down enough to keep the phaser snug to the cam but under hard acceleration it is rotating (because the pin is broken). Your cams are still timed to the crank because the chains are still on, however they now can rotate (based on chain slack) and they are moving out of spec...test your COPS, try plugs ect ect. IMHO this failure is a high possibility given the symptoms you are describing.
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04-18-2013, 02:47 PM
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Thanks guys for the input. I had all the COPs and plugs replaced last summer, I hope they would still be good. I would tend to think any issues with the plugs or COPs would trigger a code at least intermittently, or may just be my wishful thinking though. Either way, I will definitely have them rechecked.
04-18-2013, 03:35 PM
#9
Your locking pin on one or both phasers has probably sheared off...This happened to me and threw out the entire LH bank. The phaser bolt is torqued down enough to keep the phaser snug to the cam but under hard acceleration it is rotating (because the pin is broken). Your cams are still timed to the crank because the chains are still on, however they now can rotate (based on chain slack) and they are moving out of spec...test your COPS, try plugs ect ect. IMHO this failure is a high possibility given the symptoms you are describing.
Andy
07-11-2014, 03:41 PM
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I'm going through the same problem , but I just recentley (1300km) ago had a new engine installed. It was idleing a little rough and I took it to the dealer, they plugged it in and told me all 8 cylinders were firing randomly and different speeds . I got brand new CATs , new fuel filter, new plugs and coil boots. They've had the truck for 2 days and can't figure out why it's doing it