I checked the oil and noticed a little (not much at all, just enough to dilute) water in the oil. The first couple of times at fire up, the oil pressure would read 55psi and go down to 45 at idle, but now is showing 30-35psi at idle. Will water cause that much of a pressure drop? I am currently running a 10-40 as this engine has new bearings, but am ready to go to 20-50. It has about 6 hours on the new bearings.