Oil 'sheen' exhaust discharge


New member
There is a very light 'sheen' in the discharged water in one of my Lehman 135 Diesel engines. It doesn't have the usual rainbow associated with oil, but appears more like a grayish sheen. The engines hadn't been run in several years by the previous owner, who treated the boat as a floating condo. I just replaced both the oil cooler and transmission coolers and this is the first time the engine has been run since replacement.

Any advice/suggestions will be greatly appreciated.
I would say just put some hours on them while monitoring the fluid levels, temps and pressures. Probably just needs the cobwebs blown out if they are running good just do a good oil change. How old is the fuel? If you got large tanks you may want to get the fuel polished keep a close eye on your fuel filters.