N63TU engine misfire cylinder 5 (damaging exhaust gas after startup)

[MY15.50i]

2015 X5 50i with 46K miles on board, original spark plugs and coils. Car started jerking when past 3K rpm/changing speeds. Got home and fired ista and discovered engine misfire on cylinder 5.
I pulled the spark plug on cylinder 5 and noticed what can be seen in the attached pictured, doesn't look right to me. Why so dry?

The gap was pretty much non existent so I gapped it at 032, cleared codes and turned car over, gave it a few revs past 3K rpm and all was good, but didn't drive it yet.

When I changed spark plugs on my other x6 50i I did not see the spark plugs being dry at all.
I also went ahead and unplugged the spark plug from cylinder 6 and it was as dry, but gap was ok-ish.

Could this be the injectors? Wonder if no fuel is being sprayed onto the reason for the spark plug being so dry, or maybe it dried up from the heat...

[MY15.50i]

I drove it 25 miles after re-gapping the plug in cylinder 5 and no errors came back, or the jerkiness. I may have felt some slight hesitation during shifts but could have been my imagination.
My logic tells me that since re-gapping solved the obvious jerkiness, it's probably time to think about spark plug change.

[tlow98]

Originally Posted by MY15.50i

My logic tells me that since re-gapping solved the obvious jerkiness, it's probably time to think about spark plug change.

I was going to say exactly this. I think the spark plug interval change on those is pretty short right? 30,000 miles, something like that?

I’m an n55 nerd so my knowledge on the N 63 is lacking, but it seems like it’s time.

At that mileage you’re prolly fine to re-use the coils. At 70k I did coils and eldor coils so I shouldn’t need to touch the coils ever again, and bc I wouldn’t have to be in there fiddling about. If you do the coils, spring the eldors as they last forever and it’s only like $7 extra for each coil.

Wait, maybe the eldors don’t even fit your platform? Check out the n63 sub-group for better advice on that!

[Djhumvee]

I just changed my plugs in my 17 x5 50i today and that's how mine looked, all 8. I was starting to feel some shuddering? when I would get on it about a month ago, and its been getting worse. Mine had 93k miles on it now, I bought it 2 years ago with 70k, no idea when plugs were done last or if they ever were.

[PGH_X5]

Same above at just under 70k miles. Changed plugs not coils and all good. Make sure you seat all the coils back on the plugs firmly. Ask me how I know, doh

[MY15.50i]

Originally Posted by tlow98

I was going to say exactly this. I think the spark plug interval change on those is pretty short right? 30,000 miles, something like that?

I’m an n55 nerd so my knowledge on the N 63 is lacking, but it seems like it’s time.

At that mileage you’re prolly fine to re-use the coils. At 70k I did coils and eldor coils so I shouldn’t need to touch the coils ever again, and bc I wouldn’t have to be in there fiddling about. If you do the coils, spring the eldors as they last forever and it’s only like $7 extra for each coil.

Wait, maybe the eldors don’t even fit your platform? Check out the n63 sub-group for better advice on that!

I may have stretched it then. On my other x6 50i I changed plugs at 61K but I purchased the car used at 38K so the previous owner may have done them before as the coils were already Delphi and my x5 50i came with the original Bosch brand.

[MY15.50i]

Originally Posted by PGH_X5

Same above at just under 70k miles. Changed plugs not coils and all good. Make sure you seat all the coils back on the plugs firmly. Ask me how I know, doh

Oh yes I know too well from my first N63tu spark plug change

[MY15.50i]

Originally Posted by Djhumvee

I just changed my plugs in my 17 x5 50i today and that's how mine looked, all 8. I was starting to feel some shuddering? when I would get on it about a month ago, and its been getting worse. Mine had 93k miles on it now, I bought it 2 years ago with 70k, no idea when plugs were done last or if they ever were.

Cool, thanks for chiming in! I suppose I'm ok then. I was only worried because on my other N63TU the spark plugs looked smokey and also more moist, definitely not dry as these, but that was also 61K in when I pulled them out.

[MY15.50i]

Ok, the mystery deepens.

So I replaced all spark plugs and gapped them. Car ran ok-ish yesterday, it did hesitate (I pulled ISTA and no errors) but today it violently shook when I stepped on the gas pedal while I was overtaking. I pulled ISTA and still no codes.
While I was replacing spark plugs I noticed some deposits on one of the coil packs which I'm going to replace soon as soon as it will arrive in the mail.
Seems odd that coils go bad at such a low mileage but I know it's not unheard of.
Any idea of what could be happening here, maybe bad coils? And why no errors in ISTA?

[sukhk527]

Could be a faulty injector. I’d see if you can get it to stutter to try and throw the code. Normally it takes about 5-7 consistent ones to get the light to come on.

[Fknid]

Originally Posted by MY15.50i

Ok, the mystery deepens.

So I replaced all spark plugs and gapped them. Car ran ok-ish yesterday, it did hesitate (I pulled ISTA and no errors) but today it violently shook when I stepped on the gas pedal while I was overtaking. I pulled ISTA and still no codes.
While I was replacing spark plugs I noticed some deposits on one of the coil packs which I'm going to replace soon as soon as it will arrive in the mail.
Seems odd that coils go bad at such a low mileage but I know it's not unheard of.
Any idea of what could be happening here, maybe bad coils? And why no errors in ISTA?

I had a coil go bad at 80,000 kms. I think it was slowly going bad because after replacement, the engine ran so much better than it had run in the last 50,000 kms.

[dyezak]

You are lean in that cylinder. It's been lean for long enough to erode the plug and require re-gapping just to operate semi normally.

You have not addressed the root cause by re-gapping, and replacing plugs would only further mask root cause. Find the reason for the lean condition (probably the injector).

[MY15.50i]

I purchased a new set of coil packs and will replace them this Sunday. Today when I stepped on the gas the drive-train malfunction error popped up on the idrive and car started shaking. When I got home and pulled codes with ista there was misfire on engine cylinder 5 again (combustion cycle too short + fuel injection shut down).
Yeah, now I'm suspecting the injector too, we'll see. I don't feel comfortable changing the injector myself so will take it to my indy shop.

[suitedcboy]

That chart pre-dates direct injection gasoline engines. Those spark plugs look like most I remove from DI engines. DI engines reversed that 100K plus plug life trend that was so widespread. I also see many brands where once you have misfires from spark plug causes, the coils will give problems. Coil on plug is an inexpensive solution that also solves space issues. Larger coils sitting on valve cover with a short wire and well sealed quality spark plug terminal has the best track record by far. Second best is COP coils that sit in unshrouded location where engine fan air can reach them. The coils on our BMWs aren't what I just described.

[MY15.50i]

I did find a notice I received in the mail from BMW that injectors are covered up to 15 years or 150,000 miles free of charge, but that letter only mentions the VIN of my other BMW not this one.
Does anyone know if this extended warranty information is VIN specific?

[MY15.50i]

I replaced all coil packs (Bosch branded from FCPeuro) and about 1 and half week into this the car started misbehaving again, it's gotten a lot worse today. Didn't threw any codes or idrive warnings yet, but sometimes the car would shake a bit when stepping on the throttle. It's doing that randomly, if I were to mash the throttle it would not do shake at all.

After seeing how easy the injector replacement is, I'm just going to buy that tool and DIY as it looks only marginally more involved than replacing the coils and plugs. Since the last times it threw errors it only complained about cylinder 1, I'm just going to go for that one.

[bigshooter]

I'm having the exact same issue. Was driving down the highway cruising, gently gave it gas to maintain speed and it started shaking. I had to put it in sport trans to stop it from shaking. If rpms dropped it would shake the shit out of the car.

When i got home about 10 min later, I got drivetrain malfunction. Scanned with ISTA and saw misfire in cylinders 6 & 8. I also see damaging exhaust gases at start up in both cylinders, as well as fuel injection turned off.

Changed spark plugs with NGK 95706, cleared faults, and fired it up to see it immediately tripped drivetrain malfunction again.

I immediately ordered ignition coils. Bosch. Started it up and about 30-45 seconds later it tripped again. It ran rough right off the bat though.

The spark plugs were in horrendous shape. The plug in cylinder closest to the front passenger seat was corroded and did not spin freely when unthreading. Was a pain in the ass to get out. The look like it was running lean and hot. white and corroded.

So I was thinking it was the DME but after finding this thread maybe it could be the injector. I see that DME2 for cylinder bank two is highlighted due to faults registering. Any thoughts?

[MY15.50i]

Originally Posted by bigshooter

I'm having the exact same issue. Was driving down the highway cruising, gently gave it gas to maintain speed and it started shaking. I had to put it in sport trans to stop it from shaking. If rpms dropped it would shake the shit out of the car.

When i got home about 10 min later, I got drivetrain malfunction. Scanned with ISTA and saw misfire in cylinders 6 & 8. I also see damaging exhaust gases at start up in both cylinders, as well as fuel injection turned off.

Changed spark plugs with NGK 95706, cleared faults, and fired it up to see it immediately tripped drivetrain malfunction again.

I immediately ordered ignition coils. Bosch. Started it up and about 30-45 seconds later it tripped again. It ran rough right off the bat though.

The spark plugs were in horrendous shape. The plug in cylinder closest to the front passenger seat was corroded and did not spin freely when unthreading. Was a pain in the ass to get out. The look like it was running lean and hot. white and corroded.

So I was thinking it was the DME but after finding this thread maybe it could be the injector. I see that DME2 for cylinder bank two is highlighted due to faults registering. Any thoughts?

I see that one has replied and thought to provide an update.

I ended up taking the car to my indy who used a borescope and found calcium deposits on the cylinder head (#5). He suspected high oil consumption as reason and sent me to my dealer to perform factory repairs due to known service bulletin on this. I'm still below 50K so even new engine replacement should be free of charge.
However, the dealer only did the usual troubleshooting per the ISTA test plan and found injector for cylinder #5 to be affected by another service bulletin, so they replaced that injector only under Bmw extended warranty (free of charge), erased errors and called it fixed.
In fact, they even claimed the car is driving fine, the problem it is not and the moment we took it off the dealer's lot, the car started shaking again when going over 50mph. There are no errors logged even after more than 300 miles of driving, but it doesn't drive well. However, the idle is very smooth now, it was not before replacing the injector.
I took the spark plugs out, found #5 again to have a wider gap, but at least it was no longer dry. I re-gapped it but the car is still shaking when going over 50mph.
My indy now suspects engine mounts could be the problem. My suspicion is that other injectors are may be showing symptoms of failure since it's a known BMW issue.
I'm going to let it throw errors until taking it to the dealer again, otherwise they'll likely say they cannot reproduce the issue.

At least the dealer was cool with me doing my own maintenance.