The milkshake in the oil cap isn't really indicative of trouble. Many engines will do that, especially if you live ina cold or damp climate and/or drive a lot of short trips. Mine always has tan foam in the oil cap because I mostly drive back and forth to work, but it's healthy as a horse. Same story in my folks' '05 Tacoma. The oil just doesn't get hot enough for long enough to completely boil the water out of the engine.
