I changed the oil in my gen VI 502 mpi's to winterize the boat last weekend and found greenish-grey looking oil in the oil filter of one of my motors. The oil on the dipstick looked fine. I also saw some foam in the oil fill neck.

So I took the boat out today for a run with the fresh oil and new oil filter. The oil on the dipstick looked fine, but there was grey oil in the filter again and a white coating in the oil fill neck.

Could this be due to just condensation or do you think I am getting water in somewhere? The other motor had normal looking oil in the oil filter. Also, I changed the oil using a dipstick pump so probably did not get all of the old oil out.

Not sure if it matters, but I have Stainless Marine exhaust.

What are your oil and water temps?

The coating in the filler neck is condensation. They grey oil in the filter may be old sludge getting cleaned out. Water/oil mix looks like baby diahrea. The dipstick won't show anything unless you truly have an intermix problem. Did the oil level stay the same?

I think that the water temp was around 150 - 160. I don't have oil temp gauges.

The oil level stayed the same.