I used to use 40W oil in our EMD 645's. I have never been a great believer in changing out oil or filters just because a certain amount of hours have been reached. I would use it as a guide but much rather diagnose the state of the engine from the various parameters.
These engines normally have a centrifugal Glacier filter in the oil circuit. The state of the oil and cylinders can be determined from the thickness of the deposits on the Glacier bowl. I keep a record of the running hours between cleaning the Glacier bowl(start at 200 hours and extend as required) and the thickness of the deposit, which gives me an indication when to change the oil and filters, or change out piston /cylinders packages.
There is also a manometer gauge fitted to your crankcase, which is a good indication of blow-by,cylinder wear, and also injector malfunction. This will also assist with giving indication of the state of the blower and filters (either Rootes or Turbo). A crankcase reading of 1 " negative is about average.
These engines have an eductor arrangement fitted to give a slight negative pressure in the crankcase, remove crankcase corrosive gases and thus extend the life of the oil and thus the engine. Ensure this is in good order.
Offshore Engineering&Design
