Drivetrain malfunction and Cylinder 2 Misfire

[qsupra]

Brand new 2026 MT purchased 2 months ago. Driving home yesterday the car threw a drivetrain malfunction and went into limp mode. Pulled off and restarted the car, message went away and drove home fine.

Pulled the codes with Bimmerlink today and found some misfire codes which I believe may have caused the drivetrain malfunction.

Anyone experience something like this? Looking to get some opinions before taking it to a shop. Car is bone stock with ~1,800 miles

Sponsored

 

[nanaisu]

100% take it to the shop, it's under warranty. If it's a bigger problem than just the injector, coil pack, or spark plug, you definitely don't want to pay for it. Not that you want to pay for any of that anyways...
You're running 91 Octane, right? Under what conditions did the car throw the codes in? Redline? During a pull? Standard driving?
Details will be in ISTA, shop will be able to investigate, but still would be interested to know.

 

[qsupra]

100% take it to the shop, it's under warranty. If it's a bigger problem than just the injector, coil pack, or spark plug, you definitely don't want to pay for it. Not that you want to pay for any of that anyways...
You're running 91 Octane, right? Under what conditions did the car throw the codes in? Redline? During a pull? Standard driving?
Details will be in ISTA, shop will be able to investigate, but still would be interested to know.

93 octane. It happened during regular highway cruising

 

[Glorbo Jr.]

Did you ever figure out what happened? My stock 2025 has the same issues I think.

 

[qsupra]

Did you ever figure out what happened? My stock 2025 has the same issues I think.

Dealer swapped some plugs and coils around to see if it happens again in the same or a different cylinder. Hasn't happened again so far, but I've only driven the car maybe 100 miles. Snowy season in MD, so I haven't been able to drive much.

I'm thinking about maybe changing all the spark plugs myself soon since I've heard the ones from factory can be pretty trash. Other than that, no real solid answer.

 

[Glorbo Jr.]

Dealer swapped some plugs and coils around to see if it happens again in the same or a different cylinder. Hasn't happened again so far, but I've only driven the car maybe 100 miles. Snowy season in MD, so I haven't been able to drive much.

I'm thinking about maybe changing all the spark plugs myself soon since I've heard the ones from factory can be pretty trash. Other than that, no real solid answer.

Are you using an oiled engine intake filter? I installed a K&N oiled filter last december on my otherwise stock supra. Ive had the drivetrain warnings followed by limp mode twice since then, both on very cold days when I press the throttle during high way driving on sport mode. Never redlining it but at least 30-40% throttle when the boost starts building. My error codes this time were for misfires on cylinders 3, 4, and 5, which I'm thinking means issue is with the MAF and not a mechanical problem inside a specific cylinder. Maybe the oil from the K&N filter contaminating the sensor? Im ordering an OEM paper filter and going to check the MAF sensor tommorow, but if you also have an oiled filter, that would validate my hypothesis.

 

[qsupra]

No oiled filter here. Just an OEM filter when I did my first oil change around 1400mi

 

[qsupra]

And OEM intake and filter as well

 

[Evolution]

Are you using an oiled engine intake filter? I installed a K&N oiled filter last december on my otherwise stock supra. Ive had the drivetrain warnings followed by limp mode twice since then, both on very cold days when I press the throttle during high way driving on sport mode. Never redlining it but at least 30-40% throttle when the boost starts building. My error codes this time were for misfires on cylinders 3, 4, and 5, which I'm thinking means issue is with the MAF and not a mechanical problem inside a specific cylinder. Maybe the oil from the K&N filter contaminating the sensor? Im ordering an OEM paper filter and going to check the MAF sensor tommorow, but if you also have an oiled filter, that would validate my hypothesis.

our cars don’t have a MAF. It’s got nothing to do with an oiled filter.

 

[razorlab]

Are you using an oiled engine intake filter? I installed a K&N oiled filter last december on my otherwise stock supra. Ive had the drivetrain warnings followed by limp mode twice since then, both on very cold days when I press the throttle during high way driving on sport mode. Never redlining it but at least 30-40% throttle when the boost starts building. My error codes this time were for misfires on cylinders 3, 4, and 5, which I'm thinking means issue is with the MAF and not a mechanical problem inside a specific cylinder. Maybe the oil from the K&N filter contaminating the sensor? Im ordering an OEM paper filter and going to check the MAF sensor tommorow, but if you also have an oiled filter, that would validate my hypothesis.

Like Evolution already stated, the gen 2 B58 doesn’t have a MAF sensor.

 

[nanaisu]

Dealer swapped some plugs and coils around to see if it happens again in the same or a different cylinder. Hasn't happened again so far, but I've only driven the car maybe 100 miles. Snowy season in MD, so I haven't been able to drive much.

I'm thinking about maybe changing all the spark plugs myself soon since I've heard the ones from factory can be pretty trash. Other than that, no real solid answer.

I've heard that a lot of folks say the stock plugs are pretty damn good and that you shouldn't bother swapping them, or gapping them differently unless your tuner says to.

Obviously if you suspect somethings wrong with them, 100% do it. It's a disposable item. But I'm pretty sure it's not worth paying a premium for something that's not NGK, Champion (or whoever else BMW uses).

https://www.supramkv.com/threads/sparkplugs-for-tuned-supra.12329/post-497006

 

[Glorbo Jr.]

our cars don’t have a MAF. It’s got nothing to do with an oiled filter.

I guess I meant the IAT sensor. I didnt know it wasnt an MAF sensor thats in the intake housing. I've read in bmw forums that the sensor can get fouled from oil or oil vapors and cause issues with fuel/air ratio. I checked inside the intake housing and didnt see any signs of excess oil. Also checked IAT readings right after a cold start this morning and it was reading 24F when ambient temp was 18F. Not sure if that is normal or not but im going to change back to oem dry paper filter and hope that was the root cause. I dont mean to hijack the thread so Ill leave it at that.

 

[razorlab]

I guess I meant the IAT sensor. I didnt know it wasnt an MAF sensor thats in the intake housing. I've read in bmw forums that the sensor can get fouled from oil or oil vapors and cause issues with fuel/air ratio. I checked inside the intake housing and didnt see any signs of excess oil. Also checked IAT readings right after a cold start this morning and it was reading 24F when ambient temp was 18F. Not sure if that is normal or not but im going to change back to oem dry paper filter and hope that was the root cause. I dont mean to hijack the thread so Ill leave it at that.

It's a temp sensor but not the one you log with the normal software and has nothing to do with fueling. The sensors that are logged are in the charge pipe (charge temp) and/or in the intake manifold after the intercooler (IAT)

Sponsored