E84 - Many Issues

[Batso1340]

I've tried a few other internet forums with no reply, so I'm here with you guys.. Hopefully I'll get some quality tips here...

My wife's 2012 X1 E84 has always been a bit of a wild card in terms of reliability.

At the current moment, we are experiencing a number of problems which I HOPE all stem from a single source, rather than multiple system failures compounding across one another.

Issue #1 - Parasitic power draw. Left in the driveway for a week the battery will be totally drained, unable to even unlock the doors. I've checked battery draw once the car is in sleep mode, but it doesn't show any amperage being sucked down. I've put this one in the Too Hard basket to worry too much about at this point, and i doubt its related to the other problems.

Issue #2 - Uneven idling. This is an intermittent problem, sometimes its there, sometimes not. It idles in bursts, a bit like a hot car with a wild cam used to do in the days before EFI. When backing out of the driveway while this happens, the car almost kangaroos and is at risk of stalling. This also appears when driving on cruise control - the engine seems to surge while cruising, the tacho and fuel consumption metre both waver up and down in time with the surging.

Issue #3 - Almost stalling. Another intermittent problem, sometimes the car stalls or almost stalls when powering off from idle. it either hesitates and refuses to rev, or revs drop right off and the car fails to take off.

Issue #4 - Changing gears. Ive noticed that sometimes it doesn't seem to want to change up a gear. Wifey had it happen the other day where it just wouldn't change out of first regardless of revs.

Issue #5 - Puff of smoke on startup. Happens occasionally - maybe 1 in 5 starts. Doesnt use oil, doesn't blow smoke on acceleration, just a bit puff of blue smoke sometimes when starting from cold.

Issue #6 - Fuel economy (or lack thereof). This thing uses about the same as my V8 mercedes - averages around 12L/100KM around town. The best I've managed to get once is about 8L/100KM on the highway for a short while after resetting the trip computer.

I did a scan using my Autel maxi-thingy which came up with some undervoltage warnings, but after erasing them and running the car while rescanning it came back 100% clear.

So, are we talking a MAF sensor? A crank angle sensor? A PCV valve? An air leak?

Any suggestions would be greatly appreciated.

[cwickberg]

Originally Posted by Batso1340

I've tried a few other internet forums with no reply, so I'm here with you guys.. Hopefully I'll get some quality tips here...

My wife's 2012 X1 E84 has always been a bit of a wild card in terms of reliability.

At the current moment, we are experiencing a number of problems which I HOPE all stem from a single source, rather than multiple system failures compounding across one another.

Issue #1 - Parasitic power draw. Left in the driveway for a week the battery will be totally drained, unable to even unlock the doors. I've checked battery draw once the car is in sleep mode, but it doesn't show any amperage being sucked down. I've put this one in the Too Hard basket to worry too much about at this point, and i doubt its related to the other problems.

Issue #2 - Uneven idling. This is an intermittent problem, sometimes its there, sometimes not. It idles in bursts, a bit like a hot car with a wild cam used to do in the days before EFI. When backing out of the driveway while this happens, the car almost kangaroos and is at risk of stalling. This also appears when driving on cruise control - the engine seems to surge while cruising, the tacho and fuel consumption metre both waver up and down in time with the surging.

Issue #3 - Almost stalling. Another intermittent problem, sometimes the car stalls or almost stalls when powering off from idle. it either hesitates and refuses to rev, or revs drop right off and the car fails to take off.

Issue #4 - Changing gears. Ive noticed that sometimes it doesn't seem to want to change up a gear. Wifey had it happen the other day where it just wouldn't change out of first regardless of revs.

Issue #5 - Puff of smoke on startup. Happens occasionally - maybe 1 in 5 starts. Doesnt use oil, doesn't blow smoke on acceleration, just a bit puff of blue smoke sometimes when starting from cold.

Issue #6 - Fuel economy (or lack thereof). This thing uses about the same as my V8 mercedes - averages around 12L/100KM around town. The best I've managed to get once is about 8L/100KM on the highway for a short while after resetting the trip computer.

I did a scan using my Autel maxi-thingy which came up with some undervoltage warnings, but after erasing them and running the car while rescanning it came back 100% clear.

So, are we talking a MAF sensor? A crank angle sensor? A PCV valve? An air leak?

Any suggestions would be greatly appreciated.

Would be helpful to know how many miles are on it... start with a new battery. Many of your other symptoms sounds like vacuum leaks

[maxwmiller]

Hey Batso1340, I am pretty confident that I know the cause of your issue #5.

The puff of smoke at startup is almost certainly caused by the oil line connected to your turbocharger. There is a well-documented issue with the N20 engines where especially when the car sits for more than 24 hours at a time, oil slowly leaks out of the line and into the chamber of the turbocharger.

Within a second or two of starting the engine, a single cloud of blue smoke comes out, not to be seen again for the rest of the drive. Does this sound like what is happening to you?

There is an update to the oil line that you can install, which fixes the problem. However, it is likely that your turbo is approaching the end of its lifetime, as they rapidly fail around 100k miles. Mine started having boost issues around 95k and was basically worthless by 100. If you intend to keep the car for a while, it is worthwhile to look into replacing the turbo in addition to fixing the oil leak problem.

[maxwmiller]

Your other problems seem to be related to some kind of electrical or transmission issue.

Parasitic power draw is very difficult to diagnose, I would recommend unplugging any accessory in the car, including the flashlight in the glove box.

The uneven idle, weird gear shifting, bad fuel economy, etc. all could be explained by a few different issues. If not the engine, I might suspect a transmission issue.

Engine:
Check the MAF sensor, spark plugs, and O2 sensors. Any of these failing would quickly rob power and cause further issues. The other possibility is a timing chain, which would be catastrophic if failed.

Intake:
Unlikely to be a problem unless the throttle body and turbocharger are mechanically broken. There would be many signs if these were the case

Transmission:
Could be shifting poorly due to bad adaptations or a lack of proper service. BMW's "lifetime" transmission fluid claim is widely disputed, if between 50-100k miles (80-160k kilometers) have a flush done

[Batso1340]

Thanks guys,

Battery and alienator were both replaced about a year ago, not sure if I registered then correctly thru my scanner. Could possibly explain the power draw I guess?

I've recently replaced front o2 sensor.

MAF sensor also replaced a while ago, but haven't touched any of the cam sensors, crank sensors, throttle position sensors, vans sensors. Maybe one of these?

Turbo puffing oil isn't likely, it's an NA motor.

Car has about 120k kms on the clock, id be surprised if the valvetronic sas worn out.

Vacuum leak sounds the most likely I think, are there any common spots for this to happen?