P0304, engine quit, detonation?

[Jjc839]

Hi all, long time reader, first time poster.

Wife was driving my 2012 Kia Forte, up a looooong mountain grade, check engine light came on and engine quit shortly after. She managed to glide to the side of the road.

When I showed up I used my handy ELM327 to check diagnostics, and I had P0304 (cylinder misfire) on cylinders 3 and 4. Pulled the coil packs and spark plugs. This is what the plugs looked like, 1 2 3 4 left to right.

https://photos.app.goo.gl/LuWz4XdJESLKWXk67

3 and 4 look different, my best guess is that it started to knock/detonate going up the long grade, high load, low rpm, and the knock sensors shut it down. Which is strange though as it wasn't hot out (mid 50s) and I thought newer cars weren't affected by this. Bad gas maybe?

So I swapped 3 and 4 plugs with 1 and 2, cleared the codes and away it went. Bought 4 new plugs at the next town, drive it 200 miles and checked again:


https://photos.app.goo.gl/NYgnFmxQSSBjs6FY7

Better, but cylinder 4 still looks off. Maybe an injector issue?

The car has 100k miles and has been very reliable.

Any ideas?

 

[bbhero]

I'm going to ask a dumb yet simple question...


What octane gas was being run while this incident happened??

 

[Jethro_Bob]

i could be wrong but 4 looks to have oil contamination.

 

[Jjc839]

Not a dumb question, sorry forgot that rather important detail. Regular 87, all she's ever seen.

 

[Jjc839]

Originally Posted by Jethro_Bob
i could be wrong but 4 looks to have oil contamination.


It does use a bit of oil, but nothing I'm concerned about or what I would consider out of the ordinary. Around a quart every 4-5k miles.

 

[bbhero]

Ahh ok cool...

Yeah being that is isolated to that spark plug and coil... That likely was your problem.

I had a Dodge Neon that started running terrible at only 32k miles... Like really bad... Changed all 4 plugs... Car ran perfect. They put some whoopty Doo cheapo spark plugs in from the factory

 

[Mad_Hatter]

Swap the coil on #1 and #4 and see if fouling occurs on #1. If it does, then it's your coil pack. If it doesn't (and you should clearly see evidence either way cuzz that plug is new) then you've got a fouling issue (oil, fuel?) unrelated to the coil and plug that is causing your misfire

There are other, more comprehensive versions of the attached chart online.

 

[Jjc839]

Originally Posted by Mad_Hatter
Swap the coil on #1 and #4 and see if fouling occurs on #1. If it does, then it's your coil pack. If it doesn't (and you should clearly see evidence either way cuzz that plug is new) then you've got a fouling issue (oil, fuel?) unrelated to the coil and plug that is causing your misfire


Good idea I'll try that out

 

[Mad_Hatter]

Originally Posted by Jjc839
Originally Posted by Mad_Hatter
Swap the coil on #1 and #4 and see if fouling occurs on #1. If it does, then it's your coil pack. If it doesn't (and you should clearly see evidence either way cuzz that plug is new) then you've got a fouling issue (oil, fuel?) unrelated to the coil and plug that is causing your misfire


Good idea I'll try that out

A bad coil might be intermittent and not always throw a code. Coils are sensitive to heat and it's possible that loooong grade the Mrs was driving got things heated up under the hood causing the coil to fail to produce the necessary voltage for spark. By the time you arrived things cooled down a lot. It doesn't have to completely fail to throw a misfire code, just enough times that the ECU "sees" a problem on that cylinder.

When you swap the coil pack try and reproduce as much as practical, the driving your wife was doing. (similar engine temps, load). My guess is if it's the coil pack you're gonna know relatively soon after swapping. If it's not a spark issue then I'd guess it's a injector or oil issue from a leaking valve seal or worn ring. Use that attached chart and see if you can identify the deposits type on the plug.

 

[The_Nuke]

The fact that the engine quit on your wife is disconcerting. Although I am not sure I agree with your guess about how it died. If the car was going up a steep grade, it should have been under high load but also high RPM, unless it is a manual trans and was in the wrong gear for the grade. Do you know if it began to run poorly, stutter and shake immediately before dying? Or did it just up and die (after the engine light came on)?

Also, I do not believe the knock sensors can pull enough spark timing to cause the combustion process to cease to keep the engine running. They will tell the PCM about an extreme amount of knock, and it is up to the PCM to pull timing, but it has its limits. Even with the spark timing fully retarded from excessive knock, the engine should still be able to run, albeit pretty poorly no doubt.

Did your wife attempt to restart it after getting off to the side of the road? What was the outcome (I'm assuming it would not restart if she did try)? Did you try? Outcome?

You said it was misfiring on #3 and #4, and the pic appears to back that up, but you only listed the code for the cylinder 4 misfire. Was that the only one present, or was there also a P0303 code stored?

Something struck me as odd about that first pic, so I saved it off and zoomed in a little, and sure enough I think there is something definitely wrong. Unless it's just an artifact of the camera or the angle of the photo, the center electrodes on #3 and #4 are more worn than the other two. And in the case of #4, there is an extreme amount of wear on the center electrode which I wouldn't expect to see until the plug had been pressed into service well after its normal advertised service life had expired.

The last pic you posted shows that there is a fouling issue with #4, no doubt. It looks to be more of a fuel foul to me, but i'm not an expert on how plugs look when they foul. I have had oil fouled plugs plague me in the past on various motors, and they always bore a close resemblance to a dying otter washed up on the beaches of Price William Sound after the Exxon Valdez ran aground there. That #4 plug in your last pic looks more like it has been getting doused in gasoline which was not igniting or not burning completely. But again, I am not confident enough in that assessment to bet any money on it.

This one is going to be touch to diagnose given that it was a one time event (so far) and you cannot reproduce at will. Try the coil pack trick mentioned earlier and see how that ends up. If no unexpected behavior, you may have to punt and take to a pro to further diagnose.

 

[Jjc839]

Unfortunately I don't really know exactly what led up to the issue, my wife's description makes it sound like it was all rather sudden.

She said it jerked when it quit, but I chalk that up to it being an automatic and the engine quitting while it's in drive. Yes, you're right, it should shift down appropriately if the engine load is too high and rpms too low, but that theory is the only one I could come up with given the conditions.

It was a misfire code on both cylinders 3 and 4, as stated in the original post.

It very well just could've been wore out plugs, although I bought the car used I think they're originals.

 

[Jjc839]

Also, she was able to restart it after she got to the side of the road, and took it for a very short drive, but it was severely underpowered and she was worried she was going to make it worse so she shut it down. When I got there I never attempted a restart since I had no clue what was wrong at first. So I did the plug swapping after reading the codes and before attempting to restart it.

 

[Fsharp]

Diagnosing plugs is never a sure thing especially just via a picture. I'd replace all the plugs and then see if the same thing happens again (misfire codes). If so replace coils on those cylinders and go from there. Swapping up plugs and coil packs is just introducing more variables at this time however if you want to swap the coil packs i.e. 3 and 4 with 1 and 2, I would put in new plugs first to at least eliminate one possibility.

 

[bbhero]

Spark plug or coil issues... Can come up quite quickly... I have seen that before... with my Neon for example.

And in my old Nissan Sentra... Old spark plug wires caused that car to not run right.. I had changed the plugs, rotor, and distributor cap... It ran better but still not right.. I changed the wires and it got the car running right. If that had not fixed it I knew it had to have been fuel related. Thank goodness it was made right by wire change. In fact two years later same phenomen happened. Changed the wires and it ran good again.

 

[benjy]

although manufacturers tout 100,000 mile plugs in reality performance trails off after prolly 50 thou. changed OE plugs in girlfriends bought new 08 VW + got 2 more mpgs, but car ran fine + that says plugs were not optimal IMO

 

[Jjc839]

Originally Posted by Fsharp
Diagnosing plugs is never a sure thing especially just via a picture. I'd replace all the plugs and then see if the same thing happens again (misfire codes). If so replace coils on those cylinders and go from there. Swapping up plugs and coil packs is just introducing more variables at this time however if you want to swap the coil packs i.e. 3 and 4 with 1 and 2, I would put in new plugs first to at least eliminate one possibility.


Yes, I put in new plugs already. I plan on swapping coils and seeing where that leads.

 

[Mad_Hatter]

Originally Posted by The_Nuke

The last pic you posted shows that there is a fouling issue with #4, no doubt. It looks to be more of a fuel foul to me...That #4 plug in your last pic looks more like it has been getting doused in gasoline which was not igniting or not burning completely. But again, I am not confident enough in that assessment to bet any money on it.


Do 3 and 4 appear to have some glazing (oil) or appear "wet"??.. compared to 1 and 2, which look more like (to me) somewhat normal carbon build up (maybe a lil' rich though)??? Although a little bit of oil burning shouldn't cause the misfire in my experience. Just probably a sign of worn rings or valve seals. (maybe it's time for a HiMi formula)

 

[Jjc839]

I've always run Castrol edge or Mobil 1. 5w30 or 5w20, whatever is on sale. Maybe it is time to switch to a high mileage oil like you say.

Ugh, now to sift through pages on pages of which high mileage oil is best....

 

[Jjc839]

I've swapped coil packs between 1 and 4. Will report back after a bit of driving. Thanks all for the input.

 

[Mad_Hatter]

Originally Posted by Jjc839
I've swapped coil packs between 1 and 4. Will report back after a bit of driving. Thanks all for the input.

Great... curious to see what you find.

Originally Posted by Jjc839
I've always run Castrol edge or Mobil 1. 5w30 or 5w20, whatever is on sale. Maybe it is time to switch to a high mileage oil like you say.

Ugh, now to sift through pages on pages of which high mileage oil is best....


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