p0172 and p0175 extensive diagnostics done so far. Out of ideas
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04-07-2016, 10:22 AM
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p0172 and p0175 extensive diagnostics done so far. Out of ideas
So I purchased a 2004 F150 with the 5.4. When I originally purchased the truck it ran but would miss on a few cylinders. This later turned into a miss, barely start, and eventually no throttle control. Before I had ever done anything to it outside of drive it off my trailer after purchasing it.
Ultimately, I found the following problems and replaced these parts.
Passenger side chain had a partically broken guide and failed tensioner. Chain had been coming forward and eating up the reluctor wheel along with hitting timing chain cover. Throttle body had gears binding.
throttle body assembly with new tac and tps
tensioners and guides.
Reluctor wheel and crank sensor.
motorcraft plugs.
Verified fpr, fuel pump, and module are fine.
maf is working perfectly.
Fuel injectors are working correctly.
Cleaned cam sensors just incase.
Pulled vct solenoids out while I was doing other work. They looked as if they were new. I found zero sludge anywhere. Engine looked shockingly clean inside for 190k miles.
The phasers have been replaced at one point. I do not know who made them but they are not oem.
I did verify that neither chain jumped timing. On tdc I was able to verify the links were still exactly halfway apart and pointing at the cam sensors.
Truck idles perfect most of the time. But eventually it will go from 650rpm to 1000rpm in park. There are definately no vacuum leaks. Seems slightly down on power til around 2500rpm then pulls up over 5k with no issues in first.(not sure where redline is but it was pulling strong in that range til I let off) I presume the fact it is low on power is due to the two codes it will throw after about 5 miles of driving when the LTFT's get far enough out to throw the cel. I get no other codes. I am not getting smoke out of the tailpipe, but it certainly is getting very poor mileage. Bad enough to not drive it at all. I Cannot see two cats failing at once so I am very much at a loss on what is wrong with this truck. Would be nice to be able to use it since I have owned it for 5 months and driven it less than 40 miles all in the last week. It does not jerk, etc, but you can "hear" it slightly bogging on the freeway when you apply heavy enough throttle.
Ultimately, I found the following problems and replaced these parts.
Passenger side chain had a partically broken guide and failed tensioner. Chain had been coming forward and eating up the reluctor wheel along with hitting timing chain cover. Throttle body had gears binding.
throttle body assembly with new tac and tps
tensioners and guides.
Reluctor wheel and crank sensor.
motorcraft plugs.
Verified fpr, fuel pump, and module are fine.
maf is working perfectly.
Fuel injectors are working correctly.
Cleaned cam sensors just incase.
Pulled vct solenoids out while I was doing other work. They looked as if they were new. I found zero sludge anywhere. Engine looked shockingly clean inside for 190k miles.
The phasers have been replaced at one point. I do not know who made them but they are not oem.
I did verify that neither chain jumped timing. On tdc I was able to verify the links were still exactly halfway apart and pointing at the cam sensors.
Truck idles perfect most of the time. But eventually it will go from 650rpm to 1000rpm in park. There are definately no vacuum leaks. Seems slightly down on power til around 2500rpm then pulls up over 5k with no issues in first.(not sure where redline is but it was pulling strong in that range til I let off) I presume the fact it is low on power is due to the two codes it will throw after about 5 miles of driving when the LTFT's get far enough out to throw the cel. I get no other codes. I am not getting smoke out of the tailpipe, but it certainly is getting very poor mileage. Bad enough to not drive it at all. I Cannot see two cats failing at once so I am very much at a loss on what is wrong with this truck. Would be nice to be able to use it since I have owned it for 5 months and driven it less than 40 miles all in the last week. It does not jerk, etc, but you can "hear" it slightly bogging on the freeway when you apply heavy enough throttle.
Last edited by Fred Robertson; 04-07-2016 at 10:38 AM.