I turned on my 2006 1.8T this evening and the coolant warning light came on. There is between 1/2 and 1 inch of coolant in the reservoir. I noticed a small amount of white mayo like stuff under the coolant filler cap, the coolant looks clear, I can't see any oil in it. The oil level is fine, no white stuff on dip stick or under oil filler cap. The car has done 28K miles. The water pump started squeaking at 26K and was changed. Do I have a problem or should I just fill it up and keep an eye on it? Thanks, Mark.