Sounds like oil emulsion.May be the start of oil cooler problems.
Clean and refill as suggested above.
If it comes back then it's probably the oil cooler O rings.If you're unlucky it's the oil cooler.
Scaniamon
May 2012
Is there any chance there could have been rad weld or similar added to the cooling system?? Id flush the whole system and re-fill and then keep an eye on the header bottle.
DBTS
January 2012
I can answer this question...
what does white foam in a scania header tank mean?