2013 BMW X3 2.8 (N20 4-cyl turbo) DRIVING ME INSANE!!!!!!

[m3j0n]

Normally, I can fix anything, but this car has me so frustrated I'm about to set it on fire and call it a day.

Purchased a 2013 X3 2.8 (2.0L turbo) for the wife about 3 years ago with 60K on it. Her commute to work at the time was about 150 miles a day and figured it would be best to save the money on a car out of warranty, rather than a used one within warranty as she would surpass it by mileage fairly quickly.

About 4-6 months into owning it, we would occasionally get a message on the iDrive screen that stated "Drivetrain malfunction - reduced power drive carefully, reduced power" or some non-sense like that. The car would then drive like a regular 4-cyl without the turbo. No check engine light on the dash cluster. Once the car was shut off and restarted, the car would drive like normal. We did that for about a year or so as it was occasional.

I have a lead foot and my wife drives like a grandma, so we noticed it would happen much more frequently and sooner into our trips with me driving. So, I tried driving it slow, with very light throttle, staying in low RPMs before boost should come in, and noticed that the light took longer to kick on.

Over time, it has been occurring more frequently and with increased sensitivity - to now, where it comes on almost as we pull out of the driveway - at 102K miles. The car is slow as a dog and gets crappy gas mileage compared to what we used to get (used to get about 30mpg, now we get 19mpg). By the way, it was awesome that BMW announced the recall on the timing chain after we were already over the mileage....THANK YOU BMW!!

Got to the point where she needed tires, so I found a nice set of Factory M sport wheels with nearly new runflats for the same price as 4 new runflats would have been for the stock 2.8 wheels.

Only modifications I have done: Factory M sport 19" wheels, Aftermarket HID ballast and bulbs.

The car "feels" like it has no boost, but it also feels like a misfire, and it also feels like something in the drivetrain with some of the "bucking" at very slow speed. I am going insane trying to figure it out. Upon scanning the car, I only get one code - something about the boost pressure (I cant remember it off the top of my head, but will look it up again and update this thread). The car does run rich (black tail pipes), but doesnt smoke. Every BMW master tech friend that I know has looked at the car has absolutely no explanation and just tells me to sell the car, or throw parts at it.

So what have I done/found so far? The car was stating that the boost pressure was a problem. I checked the vacuum since the turbo is operated by vacuum. I found that the canister on the vanity cover was full of oil. I cleaned it out and cleared the codes. The car ran great for about 5 miles, then went into limp mode again. Checked the canister and found it filled with oil again. Noticed that there was no vacuum, so I thought I had found my issue.

I replaced the PCV diaphragm. No change. I retested and still was not getting vacuum. Verified the line to the canister was still filling with oil. Diagnosed a bad vacuum pump on the back of the motor. Replaced that, cleaned canister, cleared codes, car ran great again to the same exact spot (literally within 50 feet) where it went into limp mode the time before. I figured maybe the boost solenoid may had been fouled by the line containing oil. Replaced that, cleaned the line, cleared the code, no change. Havent done plugs or coils yet, but like I said, not getting misfire codes.

The car also stutters (feeling in the drivetrain) at slow speed when coasting/slowing to or accelerating from a red light. I have read that people have the actuator gears go bad in the transfer case, but have read that it comes with a "brake," "abs," and "4x4," light on the cluster, which I dont have. Is replacing the oil in the transfer case a waste of money at this point? Do I have to do an ecu clutch recalibration just to flush the fluid? is there a way that I can isolate that it is a faulty actuator or an internal clutch that has gone bad? If the car triggers a drivetrain malfunction light (presumably from a bad internal clutch), then there must be a sensor for this. If so, isnt it possible that the sensor is damaged or bad? Is the code for the boost independent of the drive train malfunction warning, or is once causing the other?

IM GOING INSANE!!! ANY HELP IS APPRECIATED!!! THANK YOU!

[BMTouring]

The transfer case oil replacement is a good thing to do. It's not expensive and not difficult. Get the right oil from bmw, drain it, fill it, reset it (so the car knows when to shout at you for service. doesn't seem to affect performance though if you don't reset it).

I did this recently and the car runs smoother, and no worries about that bloody thing going bad suddenly. Afaik the thing is good untill the lights come up, so you could be just in time.



Same for the gearbox, get the set (oil, pan-filter, bolts) and replace the oil. Makes gearchanges smoother


both actions resulted in a much better, smoother, behaviour. especially notable with a cold start in the morning.



I had no fault messages at all but the oil was definitely far from fresh (X3 140.000km, X5 170.000km)



Don't expect too much from the fault codes, many times they are merely pointing at some symptoms, not causes.

[LeiZ]

It's the high pressure fuel pump. $120, and call it a day.

[m3j0n]

Originally Posted by LeiZ

It's the high pressure fuel pump. $120, and call it a day.

is there a way isolate that?