Three problems related to check engine light on have been reported for the 2006 BMW X3. The most recently reported issues are listed below.
Jan 16 - check engine sensor light came on - car running sluggish. Immediately took to dealership - they detected oil separator failing. Car started smoking at dealership. They replaced the oil separator and several parts due to damage - costs $2400. March 22nd - same sensor light came on - took car back to dealership - they have had the car for 1 week and still have not told me what is wrong with it other than there is oil everywhere and I may have head gasket or engine damage. Possibly looking at another $1k to $5k. There is a manufacturer defect with this part causing serious damage to the engine. This is widely known and well documented all over the internet. This should be addressed by BMW and consumers should be given relief on the costs. BMW should support the correction of this defect and pay for the cost of repair. Dealer (chattanooga BMW) should have also informed me about the broader issue versus me finding out on my own research.
The intake boot between the mass air sensor and the throttle body cracks over time. This causes the check engine light to come on. Even though this is a known failure item, and the car is within the cpo warranty period, BMW does not cover any hoses or tubes, as they believe they are "wear" items. Since it is not covered its a $175 dollar diagnostic fee and $38. 54 for the part vs $50 deductible. You do not know if your repair is covered until the diagnostic, so short of having to take it to another mechanic to have it checked you could be penalized $125 for wanting you car repaired under the extended warranty which you paid extra for.
The contact owns a 2006 BMW X3. While driving between 60-65 mph, the contact began decelerating for traffic and the vehicle began shaking and then shut off. Approximately two minutes later, the vehicle would restart. The failure has occurred four times and has been to the dealer three times for the stalling. The dealer could not duplicate the failure. Most recently, the engine light began illuminating intermittently. The current mileage was 18,000 and failure mileage was 16,352.