Kj cylinder four spark plug covered in oil.

Eric120daniel

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I'm sorry I keep posting new threads. my liberty keeps having more and more new issues but I think I found my at least main problem for getting 10.5 mpg. I pulled all my plugs today. Tried to check gap but the feeler gage I borrowed didn't have .043 so I just made sure all the electrodes looked good. I did the plugs when I was new to working on cars so I'm glad I checked my work because they where all pretty lose. Torque them down with my ***** harbor freight torque wrench but what I believe to be cylinder four but has to be cylinder three because I got a po303 was completely covered in oil from the half the the ignition coil to the spark plug and the top half was covered in coolant from my tank leaking which I patched. I was wondering because I can't stand to wait till monday to compression test it would there be another cause besides a falty oil piston ring?
 

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DadOSix

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Couple of things Eric -

the plug could be oily from - a bad ring, leaking valve seal on either intake or exhaust or both, or possibly, the coil over the plug isnt firing , or the plug is bad.


the first thing our experts will say is to go back to the standard copper plugs and ditch the iridium.
next is - swap the suspected bad coil to another cylinder and see if the fault remains 303 or moves to where you swapped with.
of course, a compression test will tell you more, but this should be in addition to what i've listed for you.
 

Eric120daniel

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Couple of things Eric -

the plug could be oily from - a bad ring, leaking valve seal on either intake or exhaust or both, or possibly, the coil over the plug isnt firing , or the plug is bad.


the first thing our experts will say is to go back to the standard copper plugs and ditch the iridium.
next is - swap the suspected bad coil to another cylinder and see if the fault remains 303 or moves to where you swapped with.
of course, a compression test will tell you more, but this should be in addition to what i've listed for you.

Yeah I've heard copper plugs are the way to go lately. All mine looked in decent shape besides the one covered in oil. The code is weird because it's the middle cylinder on the passengers side of the engine and according to the diagram that's 4 not 3 which is what I got the code for. It set a few nights back and I cleared it to see if it would come back and I haven't seen anything. I tested all my coils with a multimeter and they all seemed to be good. It would be nice if it where valve seals because swapping out the head on my street will be a lot easier than replacing the engine.
 

DadOSix

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Yep. #4

One other thought. Your miss code might be a flakey lifter. Mine was setting 305 and 306 randomly and nit regularly. He finally tossed exhaust #5 rocker in a snowstorm a month or so back. Eased him home and decided to replace all my lifters. Because, i think if 1 collapsed, then more may follow. I didnt change rockers out because the 06 already had the newer design.

Hey @tommudd! Did you ever find the 6th lifter and rocker? Im still wanting to buy for my 04 if you had success.
 

Eric120daniel

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How often was it throwing you a 305 or 306? I think its been about a week now and I haven't gotten another code for any misfires.
 

DadOSix

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How often was it throwing you a 305 or 306? I think its been about a week now and I haven't gotten another code for any misfires.
Not often at all. Started with #6. A day or so. Ran a bit rougher then.

Cleared up 1-2 weeks

Came back as a 5.

Stayed on about w days, then cleared.

Week later in the snow, popped #5 - ran rough and tossed the rocker.
 

Eric120daniel

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Not often at all. Started with #6. A day or so. Ran a bit rougher then.

Cleared up 1-2 weeks

Came back as a 5.

Stayed on about w days, then cleared.

Week later in the snow, popped #5 - ran rough and tossed the rocker.

Oh boy lol I'm happy to say I did a compression test and I don't need an engine. I'm assuming it was due to the pcv the plugs where getting oil fowl but it could be another issue. I'm just hoping that since the misfire was on the other cylinder I'm not gonna have the same issue as you.
 
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