[VanillaBimmer]

Hey guys,

Long time lurker first time poster. Sorry if this isn't in the correct section. I tried to look up someone with my exact issue, but I feel like I need more help.

Yesterday on the way home I did a little WOT pull before getting onto my street because the engine was nice and warm so.. why not? Well I get warning lights "Drivetrain Malfunction" and the car goes into limp mode. Ugh, I have heard about this, but its now finally happened to me.

Car runs like shit, stumbling allover at idle, so I bought a scanner tool and pulled codes that I will link some screenshots of. My guess is that all of these misfire error codes are probably coming from the fact that there appears to be an issue related to the intake air temperature sensor? How do I go about diagnosing this?

So far I have pulled the MAF sensor out and cleaned it and checked the IAT reading with my scanner tool, the temperature reading seemed sensible to me... pretty close to ambient temperature when the engine was cold.

Any help on where to go from here? Is it possible I have a vacuum leak? I've heard about smoke testers.. I could buy one, but I don't want to just start dropping money on tools without direction. Any help is greatly appreciated as this car has been absolutely wringing my bank account lately.

[Netzke98]

Did you clear the code and restart the car?
Sounds like it could be a fuelling issue.
How’s your oil level?
How many km or miles on the car?
What year is the engine?
How old are the spark plugs?
How old are the coil packs?

[VanillaBimmer]

Originally Posted by Netzke98

Did you clear the code and restart the car?
Sounds like it could be a fuelling issue.
How’s your oil level?
How many km or miles on the car?
What year is the engine?
How old are the spark plugs?
How old are the coil packs?

Sorry, I should of added more background. I cleared the codes. Started the car and drove it around my neighborhood, once I gave it about 50%+ throttle it went straight back into limp mode "Drivetrain Malfunction" and misfiring like crazy. I parked it back at home and codes showing in my original post screenshots are the ones that popped up.

My car is a 2012 f30 335i with 6MT, it has the n55 engine with 93,000 miles on the odometer.

I also thought it may be a HPFP possibly, but the codes all point to some sort of air issue?

My oil level is at max, I recently topped it off because it was running low due to what I believe is a leaking Oil Filter Housing Gasket. I actually was about to conduct that repair this weekend before this new issue.

Spark plugs are fairly new, about 5 months.

Coil packs I have no idea.. is that the thing that connects to the spark plugs? I imagine those are original, but I could check the service history.

Maybe relevant, but the valve cover is also very new about 2 months. I was having rough idle issues that I believed to be a PCV issue, replacing the VC seemed to have fixed that issue.

[Netzke98]

Do you have ista or BimmerLink so you can see what your lpfp low pressure fuel pump and hpfp high pressure fuel pump are running at?
You can get a veepeak Bluetooth adapter and BimmerLink for under $100

When you know these values you’ll be able to see if it’s a fueling issue or injector issue.

Other things to verify would be:
Oil pressure
Cylinder compression
Condition of spark plugs


Yes coil packs are what attach to the spark plugs.

Is it a hobby car or do you need it daily?
Might be proactive to take it to a shop if you don’t have the time

[VanillaBimmer]

Originally Posted by Netzke98

Do you have ista or BimmerLink so you can see what your lpfp low pressure fuel pump and hpfp high pressure fuel pump are running at?
You can get a veepeak Bluetooth adapter and BimmerLink for under $100

When you know these values you’ll be able to see if it’s a fueling issue or injector issue.

Other things to verify would be:
Oil pressure
Cylinder compression
Condition of spark plugs


Yes coil packs are what attach to the spark plugs.

Is it a hobby car or do you need it daily?
Might be proactive to take it to a shop if you don’t have the time

I think that my scanner tool may be able to check the fuel pump values. I can check on that tomorrow. I also have a smoke test kit coming in to check for vacuum leaks because there is part of me that suspects this is some sort of vacuum leak. I'll check back in when I've done some more testing.

Also, this is my main car, but I have a motorcycle I can ride in the meantime weather permitting. Main plan is definitely to figure this out myself if possible.

[Netzke98]

attached is the n55 Training manual, F30 Repair manual for reference and a screen shot of the vacuum circuit. have you upgraded your charge pipe?
i couldn't post the attachments but i can dm them

[VanillaBimmer]

I did a smoke test of the engine and it appears there is definitely some sort of leak near the intake... I am not sure if this leak could potentially point to unmetered air entering and causing the engine to misfire. I know when I had the PCV issue it caused it to sputter in a similar way. I am having a really hard time placing exactly where the smoke is coming from. I took a video, but it is probably of little or no worth: https://www.youtube.com/shorts/GXmuV1efGe8

[VanillaBimmer]

I ended up fixing the issue, just wanted to post what I did here for anyone else. Replacing the ignition coils fixed the problem. Probably should of started there honestly.

While diagnosing I found out that my turbo inlet was cracked so I bought an aftermarket one from FTP https://www.ftpmotorsport.com.tw/pro...ipe-intel-pipe I can confirm that the part fits great and is higher quality than the plastic the car comes with, however, I wouldn't recommend changing it if you car runs bad as it probably isn't the issue lol. Lesson learned start with plugs and coils, they're cheap.