Originally Posted by JCL

What is often found under a valve cover on these models, is an emulsification of oil and condensation. It is often like a paste, and is light cream coloured. If that is what you have, it isn't sludge (I'm not sure what slug is, but let's discuss sludge). Sludge is dark coloured, and is comprised of dirt and byproducts of combustion, suspended in oil.

In either case, changing the oil will often clean it out. You don't need to go 3k (never drive 3000k to an oil change, that is 3 million miles), just go 100 miles and get it good and hot, then drain it and refill it with fresh oil. Change the filter every time.