Weird Oil?

[hansduker]

The oil light flickered on and off a few times on my 98 ML320 during a trip. It has done this in the past and I have just added a little synthetic Mobile oil and that has taken care of it. Went to do it this time and when I lifted the oil cap, on the underneath side and little on the opening was what I can only describe as a brownish, mustard looking substance with the consistency of pudding. The car was cold (temp. in the 20s). Any idea what this is and if it is normal -- or should I be concerned?

[mickey.1430]

moisture buildup in the oil and short winter driving distances. Very common.

[sosh]

Its an oil/water emulsion caused by condensation which is most likely to occurr with short distant driving. Perfectly normal.

[dfskinner]

Your's looked like mustard? Mine kind of looked like something my dog left in the yard after eating something he wasn't suppose to eat. (LOL)