[Model A Ron]

When I added a Mikes oil filter I did see some film buildup in the valve area. I would not call it full blown sludge as it was minor and I wiped it out. That said I am sure I have the same film buildup in the pan. I was thinking of removing a quart of oil and adding MMO. Then go for a 20 or 30 mile drive and do an oil change to flush it out. I think that's a loot better than adding kerosene for a flush like some have said.