My 6 banger has developed an oil and I am not sure where it is coming from. No huge deal but it does bother me. I have looked and I can't figure out where it is coming from. Maybe the real seal. It only leaks when it is running. You can leave it sit for a while and it will stop. Like I said no big deal. I changed the oil about a month ago and put 250 miles on it and the dipstick is just about at the full mark. Just kind of embarrassing. Thought they might have a common problemTerry