K11 Emulsified oil

Hi. Just joined so a big hello to everybody on here. Got a K11 and been driving her for the last four and a half years. Work dictates I must now travel about 400 miles a week so been doing a lot of maintenance. However, a couple of days ago I noticed a slight amount of emilsified oil in the top of the oil filler cap. Wiped it clean. Today I drained the radiator coolant etc, flushed and topped up with 50:50 ethylene glycol based coolant:deionised water. Everything is fine but again there is a slight amount of emulsified oil in the oil filler cap. Does anybody have any ideas as to wether this may be due to condensation as winter approaches? I've cleaned the coolant expansion tank internally so that I can see if the fresh coolant becomes cloudy due to cross contamination with engine oil. Last time I saw this on a car it was the cylinder head gasket. Although the engine was loosing power before I bothered to check the oil filler cap. Any advice greatly appreciated. Thanks folks.

If you have been doing short journeys then nothing to be worried about

I would imagine that hole in the oil cap will be a nice little place for a little condensation to collect

Also Check for white gunk on dipstick and if you can see in the oil filler cap to see if any gunk in there

BUT ........

IMHO, mark the water bottle level and keep an eye on the level over the next few days / weeks

If the water level drops then it would be worth getting some checks done - ie leaks, then Head Gasket etc etc
Thanks mate. Refilled coolant system today with fresh clear blue coolant right up to just beneath the max line on the res tank. There is no emulsified oil on the dip stick fortunately. Had a look in oil filler hole with torch and there is no emulsified oil to be seen anywhere. It's a restricted view but the timing chain and all visible parts are definately clear. Might be worth pointing out though that I am travelling 40 miles each way to work, 5 days a week. This speck of mayo appeared on Saturday. I wiped it clean and another speck has appeared today. Spoke to local garage owner who I know to be upfront. He said under the circumstances to not be concerned. Could be condensation. It's done 70,000 miles and peforms well. Recently took about 7 or 8mm of slack out of the throttle cable (I know...... should have done this way back). The car pulls ok and it doesn't feel as though there is any loss of power.
I also read today on the net about the possability of a poor seel when the oil filler cap is closed....... not sure about this on. Anyway, made sure cap is on tight, coolant is crystal clear and I'll monitor the level. Once again thanks for your help.