2011 M3 E90 - Loss of Power - MAF related?

[Mlizs]

Has anyone solved this issue or experienced the following: When cold, Car has a rough idle, RPM goes from 1000 to 2000 and then loss of power. No check engine light. It happens when I have my foot on the break. Changed out the following is this order (note- loss of power started happening after spark plug change):

Spark Plugs
O2 Sensors bank 1 & 2 precat
Vacuum Pump
Battery
Alternator
ECTS (engine cooling temp sensor)- next to be replaced

The car went in for Increased emissions engine malfunction. Original codes that came back before changing out the Spark Plugs were:

2B59 – coolant thermostat monitor
27E4- Vacuum sensor brake booster plausibility
2737- charge plausibility diagnosis cold start strategy bank 1 & 2
2728- oxygen sensor coast mode diagnosis before cat 1
2742 – oxygen sensor heater resistance diagnosis before cat 1
278D -alternator communication

[spammysammich]

MAF sensor isn’t used for A/F adjustment in these cars. Never use anything but the specified, spark plugs. Alternatives do not work.

[Mlizs]

Thanks for clarifying the MAF question... these are the Spark plugs I used. I was told Bosch platinum weren't the best for this car.

[spammysammich]

Those look like the right plugs. Let's go back to the basics. What is your battery voltage like? Are your grounds ok and secure? Check the ground on the under side of the car near the oil pan. Have all of the recalls been performed on the car?

Look at this thread for your brake vacuum sensor issue: https://www.m3post.com/forums/showth...highlight=27E4

[Mlizs]

I initially thought it was the battery before I changed out the alternator. So I connected the battery to a voltage reader and it would throw back "Error" so I swapped out the battery for a new one and the voltage reads between 13-14. So took it for a drive and it shut down. *Noticed that it shuts down once I go over 3rd gear gear. So I changed out the alternator and it still shuts down. Also noticed that the car is isn't running as smooth prior to changing out the Vacuum pump

i did notice though, that when the Vacuum pump was replaced I heard the buzzing sound in the fender and wasn't buzzing before. It was buzzing more often, almost every 10secs. My car didn't have any recalls, checked it out with the VIN and BMW confirmed.

i'm stressing out here... i can't figure it out. I read the VP thread you linked and I'm gonna try swapping out the sensor to see if that fixes the issue.

[Mlizs]

Also forgot to mention that I had a coolant hose leak back in October and got all over my engine... I got the check engine light at the end of December, roughly 3 months after the leak. possibly burned out a few sensors is my guess now that I'm looking back.

Thinking that changing the coolant temp sensor might do the trick since they didn't change it out when the leak happened.

[RocketyMan]

What wiring have you checked?

I wouldn't be swapping out expensive parts without verifying wiring first.

[Mlizs]

No wiring checked, besides the battery wiring.