Oil change before winterizing or in the spring?

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rh320

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Mar 2, 2018
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Another question regarding winterizing; Is it better to change the oil before winterizing so fresh oil is sitting in it all winter or wait until the spring so it starts the season with fresh oil?
 
I've usually done it before. I believe they claim it's good to change it to remove the acids and unburnt fuel. With that said, I may do the opposite this year due to lack of hours and time.
 
If you're going to do it, do it before winterizing. The are acids and such in used oil.
 
Same here, change it before winter storage. Then I run the motor 15 minutes or so to make sure the fresh oil makes its way into the lifters.
 
I always do it after because of condensation issues i worry about... Don't want to run all year on oil thats been sitting for 6 to 8 months....
 
We change oil every 100 hours or so. If I get close to 100 interval at end of season I change it if not I wait until next year and change it when we get to 100 or so. This year I changed oil in early spring, mid summer and when the boat went to bed it had less than 40 hours on the oil. Generator I change every fall as we only put 50 or so hours on it.
 
I'm for before winter block up, I would view this the same way as preparing a customer for any long block time . Block time is tough on machinery but I think its minimized with fresh ,clean oil . I also perform a very thorough fogging through spark plugs and intakes .I think despite condensation potential do to swings in temperature and humidity which run wild here in Texas over the winter, clean oil before is the lesser of two evils; combustion byproducts or condensation. Honestly I stress more over fuel and the havoc it wreaks on fuel injection systems thanks to ethanol
 
where is your hailing port sbw1 ? I am missing the seasons here in Texas but I don't miss the freeze much . Just curious about your feelings on condensation in oil during block time .
 
We are located in West Michigan near Grand Rapids. We don't have concerns with condensation as most all people store inside buildings that are heated. Before that, we did store in cold, unheated buildings and the generally accepted wisdom was to change oil at fall layup. Condensation is more of an issue here when boats are stored outside and subject to solar heating during the day, followed by freezing temps during the nighttime. Unheated storage buildings cool down slowly in the fall, and once they are cold in the winter tend to stay cold until the gradual warm up in the spring. We never experienced any moisture issues with our boats that were in cold buildings due to the absence of large temperature fluctuations. I did see problems such as mildew with boats that stayed outside during the winter months. I suppose there could have been condensation in the crankcases of these boats but the thinking was still to layup with fresh oil. Make sense to you?
 
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Thanks for the responses! The general consensus seems to be changing in the fall is better. Should an oil stabilizer be used as well? According to west marine oil stabilizers description, it coats the cylinders and other parts to prevent corrosion so is fogging the motor really necessary?
 
Fogging through the spark plug holes or intake, coat areas the oil does not, so I would consider an oil additive to be doing its job in a different part of the engine. With that said, if you are using dyno-oil, im not sure an extra oil additive is needed. Will it hurt? doubt it. For full-syn, extra coating might be good, as syn tens to run off faster then dyno-oil. Id first want to make sure the additive is compatible first, though.
 
yes makes sense
 
rh320 said:
Another question regarding winterizing; Is it better to change the oil before winterizing so fresh oil is sitting in it all winter or wait until the spring so it starts the season with fresh oil?
Click to expand...
My mechanic told me to always do it before. Two reasons first acids in used oil second to make sure there is no water in your oil. Better to have the winter to do major mechanical than in summer when you should be enjoying your boat.
 
I don't associate oil changes with any season. Change it on schedule. These mysterious acids in used oil have been talked about for decades, no one has ever seen them or noticed their affects. Winterizing to me is freeze-proofing, as long as you also meet your maintenance needs at other times. I used my boat once this year, for 1.3 engine hours. I'm not going to change the oil.
 
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No offense but, that’s just plain uninformed. Not only are acids present, they are one of THE PRIMARY ingredients used to measure engine oil degradation.

It’s science ... https://res.mdpi.com/lubricants/lub...ubricants-03-00054.pdf?filename=&attachment=1

If this is too much, chemical engineers who work for Joe Gibbs Racing have published numerous studies, with pictures.

Pertinent excerpts:

The main conclusion of this work was that ageing and engine wear lead to acid formation and antioxidant species depletion.

Viscosity, carbon residue, acid number, amount of pentane insolubles and mass losses during the test were chosen as the key parameters for the evaluation of oxidation stability of the oils.

Oxidation is the primary mechanism by which oil degradation occurs in an engine. The process of oxidation occurs in three stages. The first stage corresponds to the depletion of antioxidant and antiwear additives, followed by oxidative degradation of the base oil [2,3]. During this stage, the formation of polar organic compounds in oil (such as ketones, alcohols, carboxylic acids and esters) is more pronounced.

Engine oil ageing can be characterized by different markers like apparent activation energy of decomposition, oxidation, sulfation and nitration indices, antiwear breakdown, viscosity index, total acid number (TAN), total base number (TBN), dielectric constant and soot deposition.

Total base number (TBN) is an indirect measure of the rate at which oil acquires acidity during ageing. Engine oils contain alkaline additives like calcium sulfonate, magnesium sulfonate, phenates and salicylates [1–3] to neutralize the acids that may be generated during oxidative degradation.
 
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