It isn't caused by winter driving, it is caused by condensation. Lots of short trips, not warming it up completely to burn off the moisture, the moisture forms an emulsification with the oil mist, and then it collects over time. If you do experience winter temperatures, this is the condensate that can freeze and plug it the crankcase ventilation system.

Clean it out with a standard solvent. Check for soft hoses, and do those at the same time. Check the oil separator for any damage.

It is a reasonable idea to do a hot oil change, but that won't impact this as this component isn't in the oil circulation path so it won't be touched. If there is paste under the valve cover (check the oil fill cap) then the hot oil change will help clean that out.

Best solution going forward is to get it good and hot every now and then, as it was designed to be. What you are seeing here is a symptom of not doing that, not a problem in and of itself.

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
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