05 BMW X3 smoking out of exhaust

So much like the title states, I have a 05 BMW X3 with a 3.0L inline V6 that smokes upon starting. It doesn’t seem to occur all of the time but occasionally I will notice a large white cloud of smoke billowing form the exhaust. The dealership says that this usually do to a defective “oil separator”. I have no experience changing this part and was wondering if this would be a plausible repair for a weekend warrior type mechanic. I got quoted form the dealership close to $1,200 total to replace the part although I have NOT had them run diagnostics on it.

An inline V-6?
Wow! I would really like to see that unique engine!
;-))

Anyway, in addition to a defective oil separator, this can be due to badly worn valve guide seals.
If that is the case, and if the rate of oil consumption (you did not tell us about this factor) is not high, then you can just ignore the smoke while continuing to closely monitor the oil level.

This could also be related to using motor oil other than the expensive European specification oil called for by BMW, or it could be due to using very long oil change intervals.

How about filling in the blanks regarding the vehicle’s odometer mileage, the grade/brand/specification of oil that has been used, how often the oil is changed (in terms of both miles and months), and the rate of oil consumption in terms of X qt per 1,000 miles?

The maintenance has always been performed by the dealership according to the cars odometer reading. This past December it went through an Inspection 1 which included an oil change. By February I was getting a low oil light and took it in to get checked when, to my surprise, I found out that my warranty expired. I purchased this vehicle certified preowned but now has just over 96k miles on it. I have since added a quart of oil after checking it myself, the manual calls for 5w-?? (i forgot the last couple digits). I will have to monitor it further to devise a rate of consumption. I would estimate it to be currently around 1 qt per 2k mi.

See if you can get the Dealer to name that part in BMW speak,he is making a translation that makes me hesitate to call him on as if it is the part I think there is no way it ever cost 1200.00 to replace.

“I would estimate it to be currently around 1 qt per 2k mi.”

If it is really consuming only 1 qt per 2k miles, then you have nothing to worry about.
That rate of consumption is completely, totally, absolutely within normal and acceptable limits.
How would you like to drive a new Audi, for which consumption of 1 qt every 600 miles is deemed to be “normal” by the manufacturer?

However, you still have not told us how often the oil is changed in terms of elapsed time. Since engine sludge can be a major issue when oil change intervals become as long as the oil life monitor on a BMW allows, I suggest that you go no longer than 6 months between oil changes.

I have not kept track of my oil changes because I was still under my warranty and went in whenever the car notified me. Now that my warranty is up I will perform regular oil changes myself.

I did not get a diagnostic test by the dealership but managed to weasel that info out of them. I was thinking it was a valve seal and got a quote from a local import shop but that would be prohibitively expensive. So I have done some internet research on this part and actually found a video of how to replace it. I am just trying to weigh my options before I tear apart my car. If it is not going to ruin my engine Ill put up with it however if it is something I can replace myself then I would.