Front Cover Cavitation
The front cover on the 08 6.4 powerstroke in particular has a problem with cavitation. This is something that engineers should be way beyond now but, somehow this design flaw was over looked. The theory is the coolant is boiling coming from the EGR cooler and when it gets to the water pump the bubbles pop. Every time that the bubble pops it takes a little metal with it. Over time this chews a hole in the front cover and gets coolant in the oil. The repair for this is a new updated front cover.