One problem related to engine stall has been reported for the 2013 BMW X3. The most recently reported issues are listed below.
I am on engine number 3 on my 2013 BMW X3. First engine locked up while repair shop was investigating why egine light was on. No recall or notices at that time for vehcle and over the 50k mile warranty. Cheapest repair was finding a used engine, $8,000 vs $14,000 for BMW to repair. Turns out this was a highly noted issue with n20 code. While in shop for replacement notice comes from BMW for extended mileage service (not a recall). After repair I submitted warrantly paperwork based on letter from BMW with receipts from dealership, only to be denied. 2 years later driving down interstate 85 in north carolina summer with an infant and 3 year old engine stalled out and locked up. Took to mechanic to learn same issue as before happened still no recall - but there was a kit not for a different timing chain! I spent $6,000 this time to rebuild as the value for scrapping was minimal, mechanic which is a BMW specialist would not even consider buying for scrap due to this known issue. He also referred me to the class-action suits open for this. I have yet to receive a dime for the mfg defect. A known issue has been found, a fix has been released but no ownership of the defect by BMW.