Engine Oil Change

[Shaneesprit]

Originally Posted by skipperpete

I agree with leaving the “2 hour old oil” in the engine for the winter layup but later it occurred to me that common rail engines need special consideration due to the systemic weaknesses ( EGR) they seem to have. The oil in CR engines gets jet black in record time from what must be carbon buildup even after 2 hours operation. I’d even consider using a dry or calibration diesel fuel in the injection system for long term layup too. The game has changed dramatically since the days when 4-108’s ruled the diesel engine field.

Has the OP a Common Rail ? Not that the oil is any different, but if you have a common rail it’s the fuel you need to worry about. Doesn’t need to be special fuel but does need to be free of any water contamination or dirt. Think of an operating theatre when you think of cleanliness.

[Shaneesprit]

Originally Posted by Carl-T705

I'm sure the OP is totally confused by all the tales of don't change the oil, change the oil, run it hard before the layup run it hard after the layup. I think the funniest one is the retired Porsche restorers comment. Try this one, for the real truth. Pull an oil sample in the Fall and have it tested, pull another sample when launching and test it again. See what real authorities say about your oil samples.it isn't difficult to do. Some fluids contaminate when exposed to the atmosphere faster than others, climate plays a large role. The marine environment is harsh, salt marine even harsher. Or do nothing , I'm sure either way it will run fine in the Spring. I run a 500 HP Detroit diesel I change the oil every 200,000 to 250,000 miles whether it needs it or not. I've been doing that for the last 2.75 million miles, but I don't park it by the seaside for six months of the year, if I did I can would operate a little differently. The experts claim oil doesn't wear out , it gets contaminated.

This post doesn’t make a lot of sense.
First it says sample the oil which is a fair shout - but if your thinking of the cost and the boats out of the water. It’s a bit excessive unless you have a vast quantity of oil in the engine. That’s why it’s common place on bigger engines.
2nd running the engine hard, removes water content from the oil as water turns to stream at 100C and so leaves the crankcase via the breather.
An oil sample taken by someone that might not be familiar with how to sample the oil, is not worth that much. Although it’s not to difficult, you do need to have the engine at operating temperature.
Then you say 250,000miles on your oil without sampling? Going back to your oil sample suggestion? Not that you can’t do that I just don’t know anyone running more than 50,000miles on a truck before changing but if your doing those miles then water contamination is only likely to be an issue in an internal coolant leak. Although the Longest oil change for me was at 8000hours but wasn’t an oil change but a replacement engine. Was still running well. I would say that’s equivalent of about 200,000miles if you work your average RPM to road miles, and that was in a harsh marine environment, but it was designed for the task.
Oh then there is the oil doesn’t wear out that’s what the “Experts say” really? Which experts are these? Because oil that passes between the Camshaft and the rocker / valve. This Is a very small amount, however that oil is damaged at a molecular level. The rest of the oil is contaminated with water diesel and products of combustion.
That’s why you don’t buy cheap reconstituted oils, made of cleaned used oil.
Personally I change my oil every couple of years on the boat. Only use quality fluids.

[Captain Graham]

Originally Posted by Roniszoro

Hi All;

Life conspired against me using my boat this season, and I only used the engine for less than two hours on fresh oil and fresh filters. I can see no reason to change the oil and filters for/during the winter haul out as engine oil does not "go bad" sitting in the sump, to the best of my knowledge.

Your thoughts please? Thank you.

Look at the oil if it is dirty change it if not then don't.