Just goes to show why you should always scour the net before posting your question. From ducati.net:
The oil in my inspection window is milky? Why?
submitted by Jason Tucker
If you're referring to the old "milky sight glass syndrome", the best way to get rid of it is to go for a ride. The white, milky film is caused by water condensation. Short rides in cold weather will cause this. Go for a nice long ride that gets the engine temp up and the film should go away
If you see the white film that means you are not giving your lady enough "quality time". Get on her and get her nice and hot. Run her through the gears, tease her with the throttle hand. Go out and buy her something nice. Then let this be a lesson to you.
It makes a difference which type of oil you have in the bike. I don't have the problem of milkyness in the oil when I've used a good synthetic or semisynthetic, but I used Castrol Actevo motorcycle oil last winter and had a bad case of oil milkyness. Long rides weren't enough to make it go away either.
Switching to a semisynthetic cleared it right up.
Anyway, riding the bike in cold weather (we're talking California cold here, like 50 degrees) makes it happen and riding it in really hot weather makes it go away. The type of oil you use has a big effect on the chances of having the problem.
I'll let you all know about the end of January if I see any milkyness in the oil this time around.
I dunno 'bout y'all, but if I saw milky white oil in my window, I'd drop some out of the crankcase into an oil pan and see if I've got a contamination problem before riding...
But then again mine's water cooled. As for you air-cooled folks, your probably right it's just a little condensation around the window. In that case it's the Duc's way of saying "take me for a real ride, you pansy" ;D
Scott, that's interesting about the ACTEVO. Thats all I've used in my M1000 for the last 2 oil changes and 4000 miles or so. My results have been good, with no milky sight glass. Every morning my ride in to work , 40 miles, starts in the low 40's to mid 50's F. Afternoon ride is 90-100F. No milk ever! Maybe my late model lean calibration and 40 mile trip is enough to keep things right. I believe that oil must run 180F or there abouts minimum to keep the water away. This is no problem with my routine.
If I rode 40 miles every time I got on the bike, I'm sure I would never see any milkyness in the oil even in winter. I'm more likely to take a bunch of 2-5 mile trips with a few 30-100 mile trips thrown in occasionally. When the temperature is in the 30's my bike never warms up completely, but I try to avoid temperatures that low, since I can usually wait until the afternoon for decente temperatures any time of year.
So, one thing I did find out is that it's damn difficult to check your oil level when the window is milky... but I was barely able to make out a darker section that must be the oil I just added just under the Full line. I'm keeping a close eye on it and carrying a bottle of oil in my pack just to be safe.
I changed the oil (replaced with Mobil 1 15w50), oil filter (oem), cleaned the screen, and replaced both crush washers.
Took the girl out for a ride during my lunch break today and put a little over 40 miles on her. It was a beautiful hot sunny day here. Did about 50/50 freeway and street driving. I thought for sure the milkyness would be gone when I got back to work, but nope, still there.
Any ideas? A longer ride perhaps? Hey, any reason to bail out of the office for a nice long ride on a sunny day.