Intermittant codes on a 5.4l
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Intermittant codes on a 5.4l
2007 F-250 5.4l
I am troubleshooting a check engine light and got the codes pulled. P0340 and P0344. I cleared the codes and the light stayed on. Then a few days later, the light is off. Stays off for about 300 miles and 15 starts or so. then comes back on. a few hundred miles and the light goes off again. then back, etc. Running 5w20 Motorcraft oil with a Motorcraft filter. I know it is never the sensor but that is $32 so I swapped the bank1 side. No change.
The engine has only the following issues:
Thanks
Mike
I am troubleshooting a check engine light and got the codes pulled. P0340 and P0344. I cleared the codes and the light stayed on. Then a few days later, the light is off. Stays off for about 300 miles and 15 starts or so. then comes back on. a few hundred miles and the light goes off again. then back, etc. Running 5w20 Motorcraft oil with a Motorcraft filter. I know it is never the sensor but that is $32 so I swapped the bank1 side. No change.
The engine has only the following issues:
- Takes about 2-4 seconds of cranking to start (I have already replaced the fuel filter)
- When started, the idle is around 1200 but drops down to around 700-800 in a few seconds.
- Engine supposedly only has 34,000 miles on it. It is a replacement engine the PO put in when the phasers failed at 130k.
- It is supposed to have the updated phasers and melling oil pump. I have no way to tell if that is true.
- There is no Cam phaser knock or tick that I can hear. Only the injectors clicking.
- No chain slap that I can detect.
- Idle is smooth
- Runs perfectly fine. No miss or roughness at all.
Thanks
Mike
Fleet Mechanic
Joined: Oct 2017
Posts: 1,704
Likes: 164
From: Southwest Ohio
You are correct that changing the sensor was a waste of money.
You need to do some solid diagnostics to make sure the timing isn't off. One tooth would cause this code. I would do NOTHING until you verify the camshaft timing with a lab scope. If you don't have access to a scope you can check compression on each cylinder since one tooth off will show as low compression.
If compression is spot on, you will probably want to see if OEM phasers were installed. There's other items that could cause this, too, but it seems people cheap out on phasers.
-- Dave
You need to do some solid diagnostics to make sure the timing isn't off. One tooth would cause this code. I would do NOTHING until you verify the camshaft timing with a lab scope. If you don't have access to a scope you can check compression on each cylinder since one tooth off will show as low compression.
If compression is spot on, you will probably want to see if OEM phasers were installed. There's other items that could cause this, too, but it seems people cheap out on phasers.
-- Dave
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scottinjaxf250
1999 - 2003 7.3L Power Stroke Diesel
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