Power loss
07-30-2016, 02:10 AM
#1
Power loss
A few weeks ago I started noticing that my 2010 FX4 was running a bit rough when cold. I noticed this mostly right after startup if I let it idle forward in D with slight pressure on the brakes. Previously it had been smooth, but it was rather choppy all of a sudden and I was at a loss as to what was wrong.
The mileage was about 98k so I figured plugs were a good place to start. Did all 8 and took it for a test drive. Seemed better, but as soon as I nailed it, the truck just didn't seem to want to go, and at 4000rpm the engine light flashes and power fell off even more.
A code check the next day revealed a misfire code in cylinders 5&6. And no other codes. On the way to the dealer I accelerated to get around a semi, and the check engine light that had been solid started flashing with the associated loss of power. This time, however, an unusual vibration developed and even a hint of throttle would make it worse. After coasting for perhaps 5-10 seconds, the vibration went away and the light went solid again.
The dealer confirmed two bad coils (5&6) but the truck still lays over at over 60mph. Dealer said that he thinks it may be a plugged converter, and that it is the next logical progression in a diagnosis (also not covered on extended warranty BTW). I've specifically asked about the variable valve timing, timing belt, and lifter problems that the 5.4 is notorious for, but he insists that all seems fine.
Spark plugs were SP509s just like what came out.
O2 sensors giving no codes either meaning that the cats are still working but I suppose possible plugged. Seems odd that I have exactly no friends that have had a converter plug up, and my daughter's 200k '07 FX4 is still fine with the factory ones AND coils!
Anyone seen this sort of thing before? Am I being taken down a rabbit hole by the dealer?
The mileage was about 98k so I figured plugs were a good place to start. Did all 8 and took it for a test drive. Seemed better, but as soon as I nailed it, the truck just didn't seem to want to go, and at 4000rpm the engine light flashes and power fell off even more.
A code check the next day revealed a misfire code in cylinders 5&6. And no other codes. On the way to the dealer I accelerated to get around a semi, and the check engine light that had been solid started flashing with the associated loss of power. This time, however, an unusual vibration developed and even a hint of throttle would make it worse. After coasting for perhaps 5-10 seconds, the vibration went away and the light went solid again.
The dealer confirmed two bad coils (5&6) but the truck still lays over at over 60mph. Dealer said that he thinks it may be a plugged converter, and that it is the next logical progression in a diagnosis (also not covered on extended warranty BTW). I've specifically asked about the variable valve timing, timing belt, and lifter problems that the 5.4 is notorious for, but he insists that all seems fine.
Spark plugs were SP509s just like what came out.
O2 sensors giving no codes either meaning that the cats are still working but I suppose possible plugged. Seems odd that I have exactly no friends that have had a converter plug up, and my daughter's 200k '07 FX4 is still fine with the factory ones AND coils!
Anyone seen this sort of thing before? Am I being taken down a rabbit hole by the dealer?
07-30-2016, 07:23 AM
#2
Senior Member
I would buy a Bluetooth code scanner and do live data logging to see what is going on. BlueDriver is a good one , gives lots of info and works great with smart phones.
07-30-2016, 07:50 AM
#3
Mark
iTrader: (1)
How long did you drive it with the mis-fire condition? Mis-fire is when raw fuel is dumped into the cylinder and not ignited by the spark plug ... This fuel is then dumped into the exhaust via the cats... If it happened long enough it will degrade and become clogged
07-30-2016, 11:56 PM
#4
Drove for maybe 80 to 100 miles with the light on. Thought after the plugs were changed that the code would clear (no one would clear it for me, I was told to drive it). I didn't really push it until the freeway incident just before taking it to the dealer but I had pretty much come to the conclusion that the code was not going to clear up on its own. When I change the plugs on my daughters 2007, I remove the computer because it was just easier to get to number seven and number eight. Upon plugging it in and it had to go back through it's learning curve with the engine trouble light but it cleared in under 50 miles.
I heard from the dealer today and the catalytic converter's are fine which is pretty much what I expected. I suppose this could also be an injector issue, but I would assume that it should throw some sort of code if an injector was bad. Not convinced I don't have some sort of a valvetrain issue, but it's in their hands now.
Will update as I get more information.
I heard from the dealer today and the catalytic converter's are fine which is pretty much what I expected. I suppose this could also be an injector issue, but I would assume that it should throw some sort of code if an injector was bad. Not convinced I don't have some sort of a valvetrain issue, but it's in their hands now.
Will update as I get more information.
08-03-2016, 12:37 AM
#5
Update from the dealer.
Computer is reading a 40% ethanol blend, but I don't run E85 EVER. Plans to wipe the computer to clear all past codes and start over. Suspects that perhaps the engine knock sensor is malfunctioning too, but if it is not the sensor a new short block will probably be going in.
At 100k, I wasn't planning on a rebuild, but would it be prudent to rebuild the heads when they are off for the short block swap? The cost between a short block and a long block seem to be close to $4k, so that doesn't sound viable to me.
Thoughts anyone?
Saleen9165
Computer is reading a 40% ethanol blend, but I don't run E85 EVER. Plans to wipe the computer to clear all past codes and start over. Suspects that perhaps the engine knock sensor is malfunctioning too, but if it is not the sensor a new short block will probably be going in.
At 100k, I wasn't planning on a rebuild, but would it be prudent to rebuild the heads when they are off for the short block swap? The cost between a short block and a long block seem to be close to $4k, so that doesn't sound viable to me.
Thoughts anyone?
Saleen9165
08-03-2016, 05:54 PM
#6
Senior Member
I'm confused by what the dealer said - if it's not the sensor it will need a short block. Did they diagnose the engine? To determine it needs an engine they would have to do compression tests. Then if they found cylinders with low compression a "cylinder leak down" test would be the next step. This would tell you which part of the engine is losing compression. I think a better diagnosis is in order. I'd get a second opinion.
08-04-2016, 10:29 AM
#7
They claimed compression was fine.
Last night the service writer called and said that they drained the fuel tank and put in super unleaded (I have been running 87 octane pretty much since I got the truck with no issues). He said that the driving improved, but that the problem was still there. (also the computer's calculation for ethanol went UP). This was also done after the computer was re-flashed, so it would seem that the driveability could have also been affected by that.
Thinking that he was angling on writing this off to contaminated fuel, I told him that the fuel in the vehicle during the times these problems have manifested came from multiple sources (I keep records of where I buy and how much --- thank you mild case of OCD). I also did not share that other vehicles in the house also got fuel at those locations in the time frame so I'm pretty sure it isn't the fuel.
Road tests with the new fuel and diagnostics hooked up were inconclusive he said, and more will be done today.
They have now had it a whole week and I'm getting sick of driving this tiny little damned Ford Focus. Really need a car that I don't smack the roof line on getting in.
Saleen
Last night the service writer called and said that they drained the fuel tank and put in super unleaded (I have been running 87 octane pretty much since I got the truck with no issues). He said that the driving improved, but that the problem was still there. (also the computer's calculation for ethanol went UP). This was also done after the computer was re-flashed, so it would seem that the driveability could have also been affected by that.
Thinking that he was angling on writing this off to contaminated fuel, I told him that the fuel in the vehicle during the times these problems have manifested came from multiple sources (I keep records of where I buy and how much --- thank you mild case of OCD). I also did not share that other vehicles in the house also got fuel at those locations in the time frame so I'm pretty sure it isn't the fuel.
Road tests with the new fuel and diagnostics hooked up were inconclusive he said, and more will be done today.
They have now had it a whole week and I'm getting sick of driving this tiny little damned Ford Focus. Really need a car that I don't smack the roof line on getting in.
Saleen
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09-12-2016, 10:14 PM
#8
Update (finally!)
After nearly 7 weeks, I should have my truck back tomorrow with a new engine on warranty.
No diagnosis could be definitively made externally, so after 4 weeks of external attempts, ESP approved a removal of the motor and tear-down to look for the problem.
Upon removing the left valve cover, it was apparent that the roller tip of the rocker of the front intake valve on #3 cylinder had failed which led to the rocker arm itself breaking off. This caused the valve to remain closed and was the source of the power loss.
Metal shavings were found associated with the accelerated wear / failing of the rocker tip, and a check of bearing surfaces revealed that the whole time we were running and trying to diagnose the problem, the surfaces were being attacked by the metal. Motor is essentially trashed. Mechanic said that this isn't a common issue, but that it isn't the first one he's seen either.
New 5.4 was delivered to the dealer this afternoon and I should have the truck back as early as tomorrow.
This has been a long and frustrating road, but Legacy Ford in Rosenberg Texas has been good enough to take care of me with a loaner verhicle during the ordeal (ESP only covered 10 days of rental I think).
SO glad I purchased that extended warranty!!!!
Goes to show you that even with good maintenance you can experience a failure. At 98,600 miles this motor had ZERO sludge under the valve covers. Aluminum surfaces were completely clean with just a tint of gold to them from the oil, that's all. This was a Certified Pre-Owned truck purchased at 74K, and while I knew what kind of maintenance I did on it, I've always wondered about the first guy. Now I know.
Nice to be starting over with a fresh motor again, THANKS FORD!!!
Saleen
No diagnosis could be definitively made externally, so after 4 weeks of external attempts, ESP approved a removal of the motor and tear-down to look for the problem.
Upon removing the left valve cover, it was apparent that the roller tip of the rocker of the front intake valve on #3 cylinder had failed which led to the rocker arm itself breaking off. This caused the valve to remain closed and was the source of the power loss.
Metal shavings were found associated with the accelerated wear / failing of the rocker tip, and a check of bearing surfaces revealed that the whole time we were running and trying to diagnose the problem, the surfaces were being attacked by the metal. Motor is essentially trashed. Mechanic said that this isn't a common issue, but that it isn't the first one he's seen either.
New 5.4 was delivered to the dealer this afternoon and I should have the truck back as early as tomorrow.
This has been a long and frustrating road, but Legacy Ford in Rosenberg Texas has been good enough to take care of me with a loaner verhicle during the ordeal (ESP only covered 10 days of rental I think).
SO glad I purchased that extended warranty!!!!
Goes to show you that even with good maintenance you can experience a failure. At 98,600 miles this motor had ZERO sludge under the valve covers. Aluminum surfaces were completely clean with just a tint of gold to them from the oil, that's all. This was a Certified Pre-Owned truck purchased at 74K, and while I knew what kind of maintenance I did on it, I've always wondered about the first guy. Now I know.
Nice to be starting over with a fresh motor again, THANKS FORD!!!
Saleen
