My friend has a 2003 Lincoln Navigator with about 50k miles on it. Getting codes P0316 (misfire at start up) and P0308 (misfire cylinder no 8). It was throwing these codes a few months ago and I replaced all the plugs and coils with new motorcraft parts. Now they have come back. Any idea what could cause this other than plugs/coils? I have actually swapped the coils around again and the code remains. So this is definitely not a coil/plug issue. Truck seems to run fine there is never any noticeable missing. Thanks in advance.
03 Navigator Misfire codes..
- Thread starter nwjones18
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^^^Agreed, until you swap the coils AND the injectors you have not isolated the issue.
You reset the DTC after swapping coils around and the DTC remains indicating cylinder 8? First I would double check all connections, did you use dielectric grease on the plug boots? Are they fully seated onto the plugs? Did the coils come with new boots? Did you pull the misfiring plug? What condition is it? Did you gap the plugs?
Other than that, if you have the ability checking a mode $06 may or may not provide some useful info- such as amount of other cylinder misfires below the DTC threshold...
Other than that, if you have the ability checking a mode $06 may or may not provide some useful info- such as amount of other cylinder misfires below the DTC threshold...
Swap injectors, clear the code and see if the code migrates to another cylinder. If it were in my dealer they would run the power balance and relative compression tests through the IDS scan tool and see where the engine stands mechanically. You can also run injector tests and coil stress tests to verify their condition.
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