changing oil during spring

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Sep 17, 2012
2
Beneteau 373 Ri
My mechanic started changing the oil in the spring instead of the fall 2 years ago telling me that it was fine. I have been doing some research regarding this and all the literature points to having oil changes in the fall. I am now worried about possible engine damage caused by spring oil changes.
 
Feb 10, 2004
4,235
Hunter 40.5 Warwick, RI
Change the oil & filter in the fall. Get rid of all the accumulated dirt, acids, and other bad products of combustion stuff in the oil.

If this is wrong, then everything I have heard on this subject for the last 45 years is wrong.
 
Dec 1, 1999
2,391
Hunter 28.5 Chesapeake Bay
I'm with Rich: I think it's a better idea to change your oil in the fall just before lay-up.
 
Sep 27, 2012
7
Unknown Manufacturer 24 Lake Saint Louis
I have been a marine mechanic for 28 years and have always believed that the fall was the best option from another standpoint and that is I am already on the boat winterizing so why not change it in the fall.

I agree with the post above about the acids, dirt etc. and why wouldn't want to get that contaminated oil out of your engine? Some would argue that if you'r putting new oil in an engine that is going to condensate for the next four months or so and you would therefore start the season out with moisture contaminated oil???

You could change it both in the fall and spring to cover both issues but just the fact that you are changing your oil once a season puts you way ahead of a lot of folks that I know!

Tim
 
Jan 10, 2009
590
PDQ 32 Deale, MD
I have been a marine mechanic for 28 years and have always believed that the fall was the best option from another standpoint and that is I am already on the boat winterizing so why not change it in the fall.

I agree with the post above about the acids, dirt etc. and why wouldn't want to get that contaminated oil out of your engine? Some would argue that if you'r putting new oil in an engine that is going to condensate for the next four months or so and you would therefore start the season out with moisture contaminated oil???

You could change it both in the fall and spring to cover both issues but just the fact that you are changing your oil once a season puts you way ahead of a lot of folks that I know!

Tim
Actually, the level of condensation in the oil reaches equilibrium when the engine is warmed up and the crankcase is ventilating. It does not gradually increase in use. If the engine did somehow draw a few percent moisture in the off season, it would distill down to normal levels within 30 minutes at load.

If there is significant (more than 0.5%) water in the oil it is a leak.
 

kenn

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Apr 18, 2009
1,271
CL Sandpiper 565 Toronto
I agree with the others that fall is the preferred time to change the oil.

Having said that, I don't know if changing oil in the spring instead of the fall, by itself will cause damage in the short term, assuming good oil, effective oil filter and otherwise good care and use. It's just one factor of many in the life of your engine.

Still, if you're paying for the winterizing and spring service, you have the right to ask for the oil change in the fall.
 
Sep 25, 2008
7,695
Alden 50 Sarasota, Florida
I guess the real question here is why would anyone intentionally leave dirty acidic oil in the engine for a prolonged period? Hopefully, the original poster will ask he mechanic who recommends that to explain.
 
Dec 25, 2008
1,580
catalina 310 Elk River
I think the best advice is to change it in the fall after you have run it up to temp for the last time and it is still hot. Most of the contaminants will still be in suspension and with it hot the viscosity will be low and easier to suck out. I do mine after we pull into the marina after the 3 hour run from our mooring for the haul out.
 

Ducati

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Nov 19, 2008
380
Boatless Boatless Annapolis
Sounds like your mechanic is planting seeds for future repair work.

Oil changes should be a fall project.
 
May 27, 2012
1,152
Oday 222 Beaver Lake, Arkansas
I would change it in the fall for all the reasons suggested. Ask yourself why you change oil, and what your trying to prevent. Do you want it to sit all winter with dirty acidic carbon and fuel contaminated oil thats lost some or most of its various additives, or have nice clean fresh oil ready for another season?

I would find another mechanic.
 
Jan 4, 2006
7,650
Hunter 310 West Vancouver, B.C.
I think your first step is to get rid of your mechanic and the second step is to learn to change your own oil to ensure it's done properly.

Don't worry about the engine if it's been wintering with dirty oil for only two seasons. It's doubtful this would cause any severe damage.

Just remember that 90+% of all pleasure boat maintenance people are totally incompetent. This is just another example of the many weird stunts that have been chronicled on this site.
 
Jan 14, 2011
243
tanzer tanzer 28 bathurst nb
get him to do it in the fall to get the contaminant out of the engine a year or two will not break anything, but over time it can make a difference, or get a new mechanic if he is arguing or to lazy to do it your way since you are paying for the service.
 
Sep 17, 2012
2
Beneteau 373 Ri
Thanks for your responses. My mechanic explained to me that the oil is so good these days that it will not harm the engine if left in over the winter (he said this 2 years ago). Needless to say I trusted the mechanic and figured he knows what he is talking about since he came highly recommended.
 

RichH

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Feb 14, 2005
4,773
Tayana 37 cutter; I20/M20 SCOWS Worton Creek, MD
I guess the real question here is why would anyone intentionally leave dirty acidic oil in the engine for a prolonged period? Hopefully, the original poster will ask he mechanic who recommends that to explain.
Because most oil these days has the 'buffers' needed to maintain acidic stability ... and for each 20°C decrease in temperature the reaction rate decreases essentially by HALF.

Further if you actually ran the engine to normal operating temperature - 180+, the heat of operation will drive most of the 'water' out of the crankcase oil that does happen to be there, no to little water = no to little ionic dissociation .... although water will eventually go back into solution with the oil mixture upon long term equilibrium drive.
 
May 27, 2012
1,152
Oday 222 Beaver Lake, Arkansas
Thanks for your responses. My mechanic explained to me that the oil is so good these days that it will not harm the engine if left in over the winter (he said this 2 years ago). Needless to say I trusted the mechanic and figured he knows what he is talking about since he came highly recommended.
So let me get this straight. Your mechanic is of the belief that leaving the old oil in your engine all winter long, sitting dormant, after the engine cranked in it all summer long tearing up the long molecular chains, which now has carbon residues from combustion gases, unburned fuel from cold starts, dirt and dust that got past the filter, various metal wear particles which may corrode, and which has depleted at least some of its original additive package,...... is better than it sitting all winter with fresh new oil?

Just making sure I have a clear picture.
 
Jan 4, 2006
7,650
Hunter 310 West Vancouver, B.C.
You and Me Both ..............................

So let me get this straight. Your mechanic is of the belief that leaving the old oil in your engine all winter long, sitting dormant, after the engine cranked in it all summer long tearing up the long molecular chains, which now has carbon residues from combustion gases, unburned fuel from cold starts, dirt and dust that got past the filter, various metal wear particles which may corrode, and which has depleted at least some of its original additive package,...... is better than it sitting all winter with fresh new oil?

Just making sure I have a clear picture.
Yes, this is truly a case of common sense just flying right out the window.

Regardless of improved buffers, almost no water in the oil (not betting the ranch there), and a load of other theories, it makes less than no sense as to why anyone would prefer to leave old oil in their engines over the winter :confused:.

Fresh oil has 100% of the original protective additives, not less as does used oil.
Fresh oil contains 0% water and contaminants, not more as does used oil.

"There is nothing more uncommon than common sense"
origin Mark Twain, Thomas Chalmers, Voltaire, Frank Lloyd Wright, etc, take your pick.
 
May 27, 2012
1,152
Oday 222 Beaver Lake, Arkansas
it makes less than no sense as to why anyone would prefer to leave old oil in their engines over the winter.
I can think of a few, which is why I said he should find another mechanic. Better yet is learn to change it yourself.
 

CarlN

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Jan 4, 2009
603
Ketch 55 Bristol, RI
While I change my oil in the fall and don't understand the argument for spring, I bet this is an issue that has been blown out of proportion to the risk.

Has anyone ever seen a study that shows there's storage damage with a modern oil that has been changed on a regular schedule? What about boats in Florida that keep the same oil and sit in their slips for months at a time? You'd think that some clever entrepreneur would start offering a bi-monthly oil change to avoid "oil acid damage" (perhaps along with a bottom cleaning) :D

I can think of a bunch of behaviors that are much more likely to cause damage:

-- Not changing the oil frequently enough
-- Using the engine only for 20 minutes to get in and out of the harbor
-- Running the engine for battery charging
-- Running the engine at full speed
-- Over-propped or under-propped
-- Temperature too high or low
-- Bad fuel - including the below Yanmar spec fuel common in the US today (lubricity and cetane reduced for environmental reasons).
-- Overheating emergencies from not changing the impeller regularly or cleaning the strainer.

So if the OP's mechanic is a good mechanic (awfully rare) perhaps this shouldn't be the only reason to fire the guy.

Carl
 
Sep 25, 2008
7,695
Alden 50 Sarasota, Florida
Thanks for your responses. My mechanic explained to me that the oil is so good these days that it will not harm the engine if left in over the winter (he said this 2 years ago). Needless to say I trusted the mechanic and figured he knows what he is talking about since he came highly recommended.
Paul
I think the consensus here is pretty clear - get another mechanic
 
Jun 8, 2004
39
CS 27 - Nova Scotia (Pugwash)
Have not asked many re a Diesel Engine but for sure it is 100% recommendation to change oil in Spring for my Motorcycle, Ride on mower, and summer car...
 
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