I am not a fan of Seafoam as it can be harsh on other parts of the engine.

That said, if all it did was to emulsify the water, it wouldn't make much of a difference. It isn't a coolant leak causing this, it is condensation. Once it has emulsified (see the paste under the oil filler cap), it gets carried out the breather into the OSV, where it can freeze. If you can't get the engine hot enough to boil off the condensation (simply by driving normally once the engine is at operating temperature) then change the oil more often, and maintain the OSV and associated hoses, cleaning them out when they get clogged up. If you did use the Seafoam as you describe, you would still need to maintain the OSV, so I don't see the advantage.

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
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