This is not on an MN12 but rather my daily driver. I did a compression test on my 97 dodge avenger tonight and got a consistent 180 to 185 across the first three cylinders. However cylinder number 4 was 270, yes that's not a typo 270. I even checked it with another compression tester. I doubt this has anything to do with it but I will add anyway. It is a dohc 2.0 mitsubishi motor that has the rubber valve cover gasket with the spark plug hole gaskets as well. The number 4 spark plug hole was full of oil so I know I need to change the gaskets but oil running down into the cylinder just prior to the compression test couldn't cause higher compression could it? At least not to that extent I would think. What could possibly cause this? The car runs fine so I am baffled here. Thanks for your help.