2004 Dakota 3.7 quad cab 130k miles
#11
I'm not sure how the PCM monitors the coil secondary circuit - that's the high voltage side that fires the spark plug.
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JD33772 (07-26-2022)
#12
That's why I unplugged & turned it over
Been reading, you guys are like beyond smart sitting next to me & I appreciate any and all advice. I did have somebody tell me something possibly crankshaft sensor? Camshaft sensor? However they have their own codes that should present if they fail I think?? Not sure besides those two items and or popping in the valve cover to actually eyes on the mechanics of the valves and whatnot. The way it's firing on all the other cylinders and after replacing plugs and coil packs to still have the misfire sound and no code presenting, now I am leaning towards popping the valve cover and looking. However that will be the last thing I do. I guess I may try the camshaft sensor / crankshaft sensor they're relatively inexpensive and like I said I plan on keeping this thing even if there is a mechanical issue under the valve cover. But I'm chasing Tron I really think it's an electrical type issue. Again I'm the removal replaced guy. You tell me to remove the camshaft I'm going to learn how to do it and do it. To troubleshoot I'm a putz and it looks like I'm going to have to spend some money and take it to somebody with a super duper scanner. I don't know I'm just surprised that I cannot get any code to present since the replacement and code reset. I've started it approximately six times and run it for approximately 60 to 90 seconds don't know if that's long enough for it to register a code but the engine, it definitely sounds like it should be. ☹️
Last edited by JD33772; 07-26-2022 at 12:45 PM.
#13
Fuel system okay now I got to do a little research on that. As simple as a fuel filter? Or am I possibly looking at a sour fuel pump? Should I consider the fuel rail? Because the other cylinders seem to be firing just fine, it's just that cylinder, whichever one is making the misfire noise. Code p0 300, p0302, p2305 that presented initially, yet after replacing all the coil packs and the plugs now I'm not getting a code and yet it's still missing as originally when it presented with codes. I am leaning towards popping the valve cover but I'm not getting any kind of off sound when it just turns over. I don't know I'm confused with the code scanner because if I had fuel system issues I would think I'd have fuel system codes showing up. I hate chasing Tron 😑
#14
One of the reasons I unplugged all the coil packs so it wouldn't fire and wanted to listen to the mechanical sound. I would think I would hear something a tick a click a grind a crunch something from I'm assuming two four or six since it's on the passenger side that the sound is most prevalent in missing, unfortunately it sounds fabulous it sounds wonderful I don't have a click of crunch of grind and knock a tap at all when it's unplugged and unable to fire so it's probably not a mechanical because not a peep.
If you are turning the engine listening for mechanical issues, the engine would already be making a racket and things would have been destroyed while running, for that to happen.
#15
My Baby: 2004 Dodge Dakota 3.7l quad cab:
Got truck @99k miles & was decently maintained by previous owner. About a year & a half ago @110k I replaced both valve cover gaskets, because of a leak passenger side & PVC valve & subsequent hoses and that stopped the oil leak totally & apparently helped the vacuum system seal up as well. Had a vacuum leak I am assuming (I hate that word) because it was running noticeably better although it didn't present any vacuum associated MIL codes. Drove from Florida to Kansas twice in 2021 without a hic-up. Being a mechanic of 8yrs with jet engines & propellers in the Navy, I am inclined to do most if not all my maintenance. I have found that one word (assuming) can spend you down a rabbit $$$ hole that has no end. OK I am digressing here sorry.
My Baby @130k miles
Started truck normal & sounded fine and I let it run a few minutes to warm & spread the oil, I never ever start a motor and go, I always let it run a few before engaging. Drove 1/2 miles or so & shut off went into the store. 20 minutes later I try to start & it sounded like it engaged the starter & cut out almost as fast as I heard the starter start & stop. I turned it over & I got it started after pushing gas pedal down quite a bit & I could tell somethings missing. Drove it home & started to do the eye & ear troubleshoot. Just listening to it sounded like it was missing on passengers side, either 2,4,6 cyl. performed code scan & the following codes presented themselves:
P0300 random miss/
P0302 #2 miss/
P2305 Ign Coil B 2ndary circuit
After researching the codes, here we go, I ((assumed) as I think most would when the scanner speaks) I had a bad coil packs &or plugs @cyl #2/#5.
So I went overkill for sure but I plan on keeping her, so I replaced all 6 plugs & 6 ign coil packs. Reset codes and restarted. Sounds the same, it's still missing & nothings changed much, well honestly maybe running a tiny bit noticeably better because of the new coils & plugs but it's still sounding like the original miss cyl's #2 or 4 or 6. I redid code scan and this time the only code to present:
P0113 Intake air temp sensor (assuming) Air intake disassembled to work on coils & plugs
STUMPED
Figured I better check the mechanical sound of the engine with out the fire to listen for mechanical failures. Listening for anything, a tap, tick, crunch, clunk or grinding or anything sounding abby normal, so I unplugged all coil packs. Turned over & fortunately for me, it sounds wonderful & fine turning over without the fire. Not a tap, tick or anything mechanically abby normal sounding. I plugged all coil packs back in and put air intake back together to start back to square one.
I reset code & I started motor and not a single code presents & yet it is still sounds like it's missing. I pulled one coil pack wire at a time restarted & immediately that MIL code for each of the corresponding cyl #'s 1-6 presented. I did this for each of the 6 cyl & wrote downs codes that presented & they correspond to each cyl unplugged. Clearing codes again & having everything plugged back in and air intake reinstalled. Restarted & it sounds like the original missing & no codes are presenting after coil pack & plug replacements. Not like its all that difficult to pull the valve cover on this engine but before I go all mechanical, I am searching out help because I really feel I am chasing a (elecTron) & I have seen some videos in the past but alas cant seem to find the ones about possibly noting other sensors possibly having something to do with the misfiring. Still looking & I have verified that I have spark at each coil pack but not the strength of said spark.
I am stumped.
Any & I mean any advice is deeply appreciated.
Got truck @99k miles & was decently maintained by previous owner. About a year & a half ago @110k I replaced both valve cover gaskets, because of a leak passenger side & PVC valve & subsequent hoses and that stopped the oil leak totally & apparently helped the vacuum system seal up as well. Had a vacuum leak I am assuming (I hate that word) because it was running noticeably better although it didn't present any vacuum associated MIL codes. Drove from Florida to Kansas twice in 2021 without a hic-up. Being a mechanic of 8yrs with jet engines & propellers in the Navy, I am inclined to do most if not all my maintenance. I have found that one word (assuming) can spend you down a rabbit $$$ hole that has no end. OK I am digressing here sorry.
My Baby @130k miles
Started truck normal & sounded fine and I let it run a few minutes to warm & spread the oil, I never ever start a motor and go, I always let it run a few before engaging. Drove 1/2 miles or so & shut off went into the store. 20 minutes later I try to start & it sounded like it engaged the starter & cut out almost as fast as I heard the starter start & stop. I turned it over & I got it started after pushing gas pedal down quite a bit & I could tell somethings missing. Drove it home & started to do the eye & ear troubleshoot. Just listening to it sounded like it was missing on passengers side, either 2,4,6 cyl. performed code scan & the following codes presented themselves:
P0300 random miss/
P0302 #2 miss/
P2305 Ign Coil B 2ndary circuit
After researching the codes, here we go, I ((assumed) as I think most would when the scanner speaks) I had a bad coil packs &or plugs @cyl #2/#5.
So I went overkill for sure but I plan on keeping her, so I replaced all 6 plugs & 6 ign coil packs. Reset codes and restarted. Sounds the same, it's still missing & nothings changed much, well honestly maybe running a tiny bit noticeably better because of the new coils & plugs but it's still sounding like the original miss cyl's #2 or 4 or 6. I redid code scan and this time the only code to present:
P0113 Intake air temp sensor (assuming) Air intake disassembled to work on coils & plugs
STUMPED
Figured I better check the mechanical sound of the engine with out the fire to listen for mechanical failures. Listening for anything, a tap, tick, crunch, clunk or grinding or anything sounding abby normal, so I unplugged all coil packs. Turned over & fortunately for me, it sounds wonderful & fine turning over without the fire. Not a tap, tick or anything mechanically abby normal sounding. I plugged all coil packs back in and put air intake back together to start back to square one.
I reset code & I started motor and not a single code presents & yet it is still sounds like it's missing. I pulled one coil pack wire at a time restarted & immediately that MIL code for each of the corresponding cyl #'s 1-6 presented. I did this for each of the 6 cyl & wrote downs codes that presented & they correspond to each cyl unplugged. Clearing codes again & having everything plugged back in and air intake reinstalled. Restarted & it sounds like the original missing & no codes are presenting after coil pack & plug replacements. Not like its all that difficult to pull the valve cover on this engine but before I go all mechanical, I am searching out help because I really feel I am chasing a (elecTron) & I have seen some videos in the past but alas cant seem to find the ones about possibly noting other sensors possibly having something to do with the misfiring. Still looking & I have verified that I have spark at each coil pack but not the strength of said spark.
I am stumped.
Any & I mean any advice is deeply appreciated.
#16
Do a power balance test. Get the engine fully warmed up, let it get to a comfortable idle, then disable IAC. (if you have one.... not sure how that works on the throttle-by-wire fellers) Then, unplug one coil pack at a time, and see what the engine does. (leave it running the whole time.) cylinders that DON'T make a change in idle speed are the ones that are misfiring. Once you have determined the culprit(s), figger out WHY they are misfiring. Use a spare spark plug to test spark, rent/borrow some noid lights to verify the PCM is pulsing the injector. If all of that checks good, compression test. See what the numbers look like.
Or, you could just jump directly to the compression test. That will tell you if you have a mechanical problem.
Or, you could just jump directly to the compression test. That will tell you if you have a mechanical problem.
#17
Hopefully I can get to it this weekend.
Do a power balance test. Get the engine fully warmed up, let it get to a comfortable idle, then disable IAC. (if you have one.... not sure how that works on the throttle-by-wire fellers) Then, unplug one coil pack at a time, and see what the engine does. (leave it running the whole time.) cylinders that DON'T make a change in idle speed are the ones that are misfiring. Once you have determined the culprit(s), figger out WHY they are misfiring. Use a spare spark plug to test spark, rent/borrow some noid lights to verify the PCM is pulsing the injector. If all of that checks good, compression test. See what the numbers look like.
Or, you could just jump directly to the compression test. That will tell you if you have a mechanical problem.
Or, you could just jump directly to the compression test. That will tell you if you have a mechanical problem.
#18
#19
Kind of feel like I may be isolating the situation however, when I preformed new code scan to see the codes unfortunately now the only codes that presented: P0113 (assuming) air cleaner disassembled, and now P2314 associated with cylinder #5. Now that throws me off because the only time the 2314 showed up before was the first time I pulled each coil pack individually to set & see the code that it would present. I unplugged the cylinders one by one and the only codes that shows up are the ones above. Eventually I will be doing the compression test sometime next week when my neck calms down but I really feel like I'm chasing Tron.
Again thank you for your information and advice, although I am still seeking a solution so anybody else that may have something to throw in here👍 I deeply appreciate the knowledge base in this forum.
#20
I would ignore any codes you get while testing..... Not sure what criterion the PCM uses for misfire codes, but, on my truck, I had a dead miss on one cylinder, as the plug wire was in two pieces..... and it never set a code....
Cylinder 2 seems to be your problem child though. If you hadn't replaced all the coils, I would be tempted to swap 2 and 4, and see if the misfire moves with the coil. Might try it anyway.
Cylinder 2 seems to be your problem child though. If you hadn't replaced all the coils, I would be tempted to swap 2 and 4, and see if the misfire moves with the coil. Might try it anyway.