What would be causing sludge to be on my oil cap and some just inside the cap?

I changed my oil in my car and noticed some sludge on the cap, I wiped it off and dismissed it as condensation. About 1500 miles later I checked my cap again and there was a good amount of sludge on and around the cap. I have been leaking coolant, but I have checked my dipstick quite often and the oil is normal and not creamy or anything. My dad broke the little plastic tube that runs to my PCV valve and we taped the tube with a piece of a pen in the tubr to keep it together so it might be the restricted air causing the condensation not to evaporate. I am just not sure what's going.