Drivetrain Malfunction.

[SlimM5]

So I received the dreaded drivetrain malfunction. I checked the spark plugs and coils and cylinder 7's coil was cracked.

However, after changing the coils and sparks, the car still doesn't sound or feel right. And I smell a high emissions odor. Since my M5 is a 2014 with only 58,000 miles, I should still qualify for the "extended warranty" from BMW to deal with the fuel injectors, right? I've heard that dealers will fix this issue if the car is within 10 years or 100k miles.

If not the fuel injectors, then not sure what else could be the issue. Maybe MAFs? I changed my filters during my last oil change and used the cheap orange BMW filters. SMH

[MFM5]

Had the same problem with my '15 at 65K miles. Waiting at a stop light, car juddered and drivetrain malfunction popped up on the screen. Was about 5 miles from home and got it back home but it was running rough. Had the car flat bedded to the dealer. They diagnosed a bad injector, and replaced all injectors at no charge due to the injector extended warranty.

[SlimM5]

Originally Posted by MFM5

Had the same problem with my '15 at 65K miles. Waiting at a stop light, car juddered and drivetrain malfunction popped up on the screen. Was about 5 miles from home and got it back home but it was running rough. Had the car flat bedded to the dealer. They diagnosed a bad injector, and replaced all injectors at no charge due to the injector extended warranty.

Well that gives me peace of mind. I'll make an appointment ASAP and have it towed in.

Same happened to me. On my way to work, dropped down a gear and bam! Uno reverse card. Luckily, chugged along to work and back.

How's your car running now?

[MFM5]

Originally Posted by SlimM5

How's your car running now?

Added 10K miles since the injector replacement and running perfect. Report back once you get the dealer diagnosis.

[M5Rick]

To preserve injectors I use redex injector cleaner, the original stuff, once every 3-4 tankfuls to keep the jets running sweet not forgetting to replace the fuel filter every 25k miles.

[SlimM5]

Originally Posted by MFM5

Added 10K miles since the injector replacement and running perfect. Report back once you get the dealer diagnosis.

I will have to wait until next Friday, as the dealer currently does not have any loaners available until then.
I am leaning towards fuel injectors being the problem. Hopefully a pretty quick fix and turnaround time. 🤞

[SlimM5]

Minor update . . . So BMW covered the fuel injector feeding cylinder 7. SA states that the car was still going into protect mode. They ran diagnostics and the DME failed. This was the source of my false rear diff warning. BMW also covered this, thankfully.
Picked up the car today and it went into limp mode again, not even 10 miles into driving. I pull over to the side of the road and called my SA. He says, bring it back in if I can. I restart, the limp mode goes away, but the car definitely does not feel right. The rpm's kept bouncing while idle and the engine was very rough, as if trying to misfire. I definitely was not receiving full power.

Anyway, back to the drawing board.
Any thoughts on what could be the issue?

I'm leaning towards the rest of the injectors.

[M5_Raz]

Bad MAFs can definitely cause this. Same for Oxygen sensors, especially the ones before the cats.

Are they sure they replaced the correct DME? Maybe the other one is also bad..

[SlimM5]

Originally Posted by M5_Raz

Bad MAFs can definitely cause this. Same for Oxygen sensors, especially the ones before the cats.

Are they sure they replaced the correct DME? Maybe the other one is also bad..

I would hope so. I never really had the car back long enough to look under the hood and see what was replaced.
It's just weird to me that I'm having the same issue that happened the same exact way after coming back from service. Could bad gas also be a factor?
I use Costco whenever I can't get to Shell, but never really had any issues with fuel.
Hopefully this is an easy fix since they know what the issues are related to.

At this point it's either the other injectors, the other DME, MAF's, or O2 sensors.

By the way, the strong gas odor I had before turning it in the 1st time was gone, if that counts for anything.

[M5Rick]

Originally Posted by SlimM5

I would hope so. I never really had the car back long enough to look under the hood and see what was replaced.
It's just weird to me that I'm having the same issue that happened the same exact way after coming back from service. Could bad gas also be a factor?
I use Costco whenever I can't get to Shell, but never really had any issues with fuel.
Hopefully this is an easy fix since they know what the issues are related to.

At this point it's either the other injectors, the other DME, MAF's, or O2 sensors.

By the way, the strong gas odor I had before turning it in the 1st time was gone, if that counts for anything.

There's a new Texaco fuel out in the UK, it's called Supreme 99 Performance+, the highest RON they have ever come out with, with performance additives and the plus is that it contains no ethanol which would be perfect for M cars.
Not sure whether it's available in US and it's only at selected stations here.

[SlimM5]

Dealer called and the updated diagnosis is a bad spark plug. Don't know how that could have been since all the plugs and coils were changed prior to service. They did the usual coil swap from cylinder 6 to cylinder 5 and the fault stayed at 6. When they changed the plug, the fault moved with it. So bad plug.
Makes me wonder how a new plug goes bad that quickly? 🤔
Maybe saturated with fuel before the fix?
At any rate, my SA is keeping the car a while for some extensive driving for any other engine shudder.

As for gas, the US isn't really great at having top notch gas stations like EU. 😕
The really, really good ones are far and few between.

[M5_Raz]

It's possible you got a bad one from new.

Yeah fuel is terrible here, especially on the west coast. I only use stuff labeled with the government Top Tier label.

[DL7]

When an injector goes bad and depending on the severity of leakage, the spark plug can get fuel fouled and the engine oil can get contaminated with fuel. I have heard about cases of excess fuel from a failed injector causing hydro lock. My understanding of best practice is to change the plug from the cylinder with the failed injector and also change the engine oil.

I recently had 2 injectors fail on the highway and cause a dangerous complete loss of engine power. I plan to post what happened but haven’t had a chance yet.

[SlimM5]

Interesting. The good thing is once I started having drivetrain malfunction, I stopped driving the car and left it parked.
Since I recently changed the oil, are you suggesting to change it again, as a precaution?
I don't think the leak was severe enough to contaminate the oil.

[DL7]

In my opinion it really depends on the severity of your injector failure and how much fuel could have gotten in your oil which is hard to say. My understanding is that fuel in the oil will adversely impact the lubricating properties of the oil. In my case, during repair they determined my oil to be contaminated and changed it as part of the repair covered by the extended injector warranty. However, they initially were not going to cover the oil change and I was going to pay for one as a precaution.

[SlimM5]

I can definitely bring this up to my SA and have them check it out. Out of an abundance caution, I guess it wouldn't hurt to have the oil changed again. Better to be safe than sorry.

[SlimM5]

Picked up the beast yesterday and she's running smooth again. No more lean fuel in cylinders. As for the new spark plugs going bad, turns out 2 were defective. I did ask what was causing the plugs to misfire brand new, and that was the diagnosis. Compression test came back okay, so all seems good from there.
Will update after driving for a few days to stretch its legs a bit.

[m5bbq]

i was watching a youtube video on how to diy spark plugs and the poster said something about coils being pia to seat onto the plugs properly and the wire harness being little tricky to seat all the way. It probably wasn't anything serious. these cars aren't glass. M cars love to be beaten on... with fresh fluids at operative temps

[SlimM5]

It's been 2 weeks now and everything is still running fine. Out of caution, I've added fuel injector cleaner with each fill up. So hoping to prevent any further injector failures anytime soon.