Whats the point of changing oil for winter hybernation?

[bsh21wash]

Why do they say to change the oil for winter sitting? Wont it collect moisture during this time and you'll have to end up changing it in the spring anyway?

 

[45Auto]

Re: Whats the point of changing oil for winter hybernation?

The reason for changing it is because if it does have some moisture in it - even such little bit you can't see it, not enough to form "chocolate milk", no seals are perfect - then you don't have that moisture sitting against your bearings and shafts and gears all winter.

 

[danfrompgh]

Re: Whats the point of changing oil for winter hybernation?

Exactly...oil changes are $ooo cheap compared to the alt. Change it again after it has sat all winter and you wont go wrong.

 

[Manipulator]

Re: Whats the point of changing oil for winter hybernation?

I change mine every fall. Is it standard protocol to change the oil in the spring? I never do, just curious.

 

[cbavier]

Re: Whats the point of changing oil for winter hybernation?

My Marina changes Oil and Filter and ALL fluids including outdrive in the fall when they winterize my I/O The reason is so any water or moisture will be drained away. My boat is a 1986 and the same Marina has done it since it was new. I've never had a problem. Incidently along with the Winterization the cost also includes Spring Prep. $144 to winterize, change oil and filter if your interested. Four Winns Horizon 190

It has 638 hours on it too.

 

[KnottyBuoyz]

Re: Whats the point of changing oil for winter hybernation?

Along with water/moisture in the oil, used oil is also acidic from the byproducts of combustion that get in it. Leaving your bearings to sit in acidic oil over the winter isn't exactly the best for them.

Last ship I worked on had a lab that tested the lube oil from the engines and generators regularily. With extremely efficient oil purifiers (centrifuge type) they could remove the particle contaminants easily but not the acidity. This was their primary indicator of needing the oil changed. These engines used about 500 litres of oil each (x4) so it doesn't get changed at any regular interval, such as months or miles or hours like we do with our cars and boats. Sometimes, depending on the quality of the fuel these engines would only need a complete oil change about every 9-11 months even under heavy use.

 

[Scaaty]

Re: Whats the point of changing oil for winter hybernation?

"used oil is also acidic from the byproducts of combustion that get in it. Leaving your bearings to sit in acidic oil over the winter isn't exactly the best for them"

I don't think this can be stressed enough

 

[backwater dawg]

Re: Whats the point of changing oil for winter hybernation?

I don't know???? I have twin 260"s--1988--2200 hours--runs perfect--never have had a value cover off--I have NEVER changed oil in the fall--first thing in the spring and it seems good to go---I think everone does some of this stuff different---I also NEVER fill my gas tanks--put some stab in them--run them both dry and fill and change water seperaters in the spring--I have never had any fuel problems--just had the carbs rebuilt this summer for the first time not due to sludge--just worn out--good luck--Steve

 

[Don S]

Re: Whats the point of changing oil for winter hybernation?

Any moisture from condensation is going to burn off when you take it for a good run. But what about all the fuel and acids that builds up in the oil over the season of running the boat. If you mind that old oil on your bearings, crank, cam, etc. etc. all winter don't change it.
There are people that never change there engine oil and drive oil except every 5 or 10 years, and some survive.
Now you might get a little moisture from sitting all winter. But it will burn off. How about the fuel, acids, carbon and all the other stuff.

 

[Mischief Managed]

Re: Whats the point of changing oil for winter hybernation?

Acids do indeed form in oil, but motor oil has buffers in it that neutralize the acids as they form so the acids are not a problem until the buffers are used up. Fortunately, there's a lot more buffer capacity than is necessary for typical change intervals. That same "acidic" oil you are worried about leaving in all Winter, was in there all Summer too...

I have steel parts from a motorcycle transmission that sat in well-used (6000 mile) motor oil for 5 years, sitting on a shelf in my garage. They have no corrosion, whatsoever. Nor do the crankshaft, pistons, or rod bearings from the same engine.

I change mine once in the Fall, immediately after my last trip out as part of my Winterizing routine. It's easy to pump when the engine is hot. I only do 70 hours a season so it's an yearly event for me.

 

[John_S]

Re: Whats the point of changing oil for winter hybernation?

Many winterizing procedures call for fogging and shutdown of the engine. Then the oil and filter is changed. The engine is not restarted to pump the new oil through the bearings. ie the old acid laden oil is still in contact with the bearings. If you are going to change it, at least pump the new through the system.

 

[SuperNova]

Re: Whats the point of changing oil for winter hybernation?

Many winterizing procedures call for fogging and shutdown of the engine. Then the oil and filter is changed. The engine is not restarted to pump the new oil through the bearings. ie the old acid laden oil is still in contact with the bearings. If you are going to change it, at least pump the new through the system.

Exactly my thought. If you don't run the engine to cylcle the oil after you change it, all you are doing is filling the pan and the old oil stays in the bearings, etc. For the record, I change my oils based on run time, not on whether I am storing it or not. Mischief is also correct in this regard, oil is not worn out or acidic until the additive package is used up. Until then it protects the engine just fine, storage or not. My opinion.
--
Stan