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Roniszoro · 22-09-2022, 05:30

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.

Wolfe10 · 22-09-2022, 05:46

If those two hours of running were long enough at a time (particularly last time it was run) that the oil, not just coolant got up to operating temperature, I would not change it.

But, if it did not get warm enough to boil off the moisture (a normal byproduct of combustion) I would.

So, started only to go in and out the the marina-- change it.

Run at least an hour going somewhere-- don't change it.

Same for land-based diesels.

Rumrace · 22-09-2022, 08:30

Yup oil change. The acid in sitting oil can cause damage, but that’s really old news unless you are using the low grade single grade oils which have not made the huge improvements. Id say you were safe with today’s detergent packages. Diesel oils have more adders than gas lubes. Filters I’m not as keen on letting sit. They can go solid in an area reducing flow.

rslifkin · 22-09-2022, 08:33

With only 2 hours on the oil, I'd just make sure you get it good and hot before winterizing and call it good. Ordinarily I'd be in the "change it" camp, but 2 hours is so little use that as long as you haven't been piling up major moisture and fuel dilution in the oil, it'll be fine.

Sailmonkey · 22-09-2022, 08:36

Id say leave it, provided you run it good and hard for 30 minutes or so prior to layup to ensure the oil is hot and dry.

sailorboy1 · 22-09-2022, 10:20

I wouldn't change it!

I didn't even change my 200 hour oil before hauling out as I think this acid thing is old school crazy based on oil from 100 years ago.

rslifkin · 22-09-2022, 10:38

Quote:

Originally Posted by sailorboy1

I wouldn't change it!

I didn't even change my 200 hour oil before hauling out as I think this acid thing is old school crazy based on oil from 100 years ago.

As oil gets used it does accumulate fuel, moisture, acids, etc. However, the oil has an ability to buffer some amount of acid, making it not much of an issue. Generally I don't mind storing an engine with old oil if it's well before the change interval. But if it's getting somewhat close to the change interval, it's safer to just change it in my mind.

Drumroll30 · 22-09-2022, 13:26

Quote:

Originally Posted by sailorboy1

I wouldn't change it!

I didn't even change my 200 hour oil before hauling out as I think this acid thing is old school crazy based on oil from 100 years ago.

If your hauling out you'll be removing sails along with a long list of related tasks. If I had 200 hours on my oil I'd spend the 45 minutes it takes, your into the list of jobs anyways so why not.

NYSail · 22-09-2022, 15:15

I’d change it…..

MicHughV · 22-09-2022, 15:33

new oil and filter = $70 maybe ???

peace of mind = priceless !!

smj · 22-09-2022, 15:39

Quote:

Originally Posted by MicHughV

new oil and filter = $70 maybe ???

peace of mind = priceless !!

Exactly

**skipperpete** · 22-09-2022, 21:27

Quote:

Originally Posted by sailorboy1

I wouldn't change it!

I didn't even change my 200 hour oil before hauling out as I think this acid thing is old school crazy based on oil from 100 years ago.

200 hrs is pushing the limits a bit but I agree about the acid theory, I’ve never seen acid damage from acidic oil in a diesel engine ....but have repeatedly heard the acidic/ corrosive lube oil story. It might be true and I just never encountered it ( I’ve opened up a lot of diesel engines ) so I won’t try and discourage forum members from doing preemptive oil changes.
If you really want to stop corrosion and be nice to your engine, either disconnect the wet exhaust at the mixer elbow at layup time or run a coolant/freshwater mix through the raw water circuit before shutdown.

DumnMad · 23-09-2022, 02:21

Quote:

Originally Posted by sailorboy1

I wouldn't change it!

I didn't even change my 200 hour oil before hauling out as I think this acid thing is old school crazy based on oil from 100 years ago.

Agreed. Modern oils sticks to the steel better and do not squeeze out of the bearings like olden day natural oils. Long haul trucks commonly do 400hrs between oil changes.
I'd say very short haul boats 100hrs.
Medium haul boats 200hrs.
Long haul boats 400hrs.
Race boats that hardly get the engine warm should have electric motors.

https://www.fleetequipmentmag.com/oi...should-extend/

See the Cummins: ODI 50,000 miles at lower revs -- say 500hrs @ 100mph.

Manateeman · 23-09-2022, 03:48

Good size shot of Marvel Mystery Oil. Run it good and warm. FRESH water flush the raw water side. Get a drain installed in the water lift. Keep bugs and four leg guys out of the inlet and exhaust. We had a rat move in our exhaust while building our boat...they are good climbers. Turn it over by hand a few times in the winter. Turn, not spin. Take the belt off, clean off the rust, paint lightly. Do your battery duties. Good time to change the impeller, clean heat exchanger, hose clamps to running gear...now is the time to spend on your engine.
Happy trails to you
Mark and the manatee crew.