Am I changing the oil too often?

[RaymondR]

Originally Posted by valhalla360

Doesn't answer the question. Not questioning if it can cause more wear...it's how much extra wear relative to the life of an engine.

20,000hr is likely several standard deviations above typical users over 20-30yrs of ownership. So yeah, odds are for the vast majority, the engine will rust away long before it wears out.

When you polish anything, such as metals or telescope lenses or mirrors, you are abrading away surface layers with a harder granular material and if the abrasive is very fine you would take forever to abrade away any significant amount.

A thread drifting snippet.

As well as roller and ball bearings oil drillers use journal bearings in some of their drill bits for extended life. The bearing surfaces are tungsten carbide inserts and the lubricants grease and silver. The silver is contained in grooves between the inserts on the outer race.

[gmakhs]

My manufacture says every 50 hours ... I do change every 50 hours anyway is just 2 litters and I haven't done 50 hours the past 6 months .... It's a sailboat .

[nmccubbin]

We have a Beta with the shallow sump option. Beta recommends more frequent changes for this than the standard sump. Presumably because concentration of junk in oil is higher with the lower volume of oil
In any event, oil is cheaper than parts. Oil changing labour is less than rebuilding
We installed an electric pump to pump out old oil and pump in the new stuff. Makes changing relatively easy

[GinoDelG]

Get the oil tested and they’ll tell you how many hours to go till the next change. I have mine tested every change. Well worth the $30.

[ShoreFun]

I come from the antique car community plus my brother is a Mercedes mechanic.
So here are some thoughts.

First you need to understand oil. What does it do first, lubricates. When does not not lubricate, well when it breaks down. What breaks it down, well modern oils pretty much only breakdown with heat. Synthetics take real high heat to break down, hence their use on race cars and turbo cars. What are the odds you are running your boat engine hot enough to break down the lubrication, not very high.

Next and the most important thing is how it protects the engine. The additives or sometimes called detergents. No not the detergents like cleaning around the house, the chemical idea of detergents (my chem is not so good) using a different set of chemicals. They will surround 'dirt's and keep them in suspension so they do not form sludge and chemically react with bad stuff to prevent acids. It is when these are used up that you have a problem (this was mention much earlier in this thread).

Zinc is only a factor in engines with high valve spring tension. Currently the zinc is at levels seen in the 50's. Not an issue with these engines.

So then how often does this need to be done. What let us consider what my brother has observed rebuilding thousands of diesel engines. He has never seen an engine fail from old oil. No oil, yes, old oil no. He has had more than one customer that ran 100,000 miles between oil changes. I should say the only changed the oil when something else needed work. These people did make sure there was oil in the engine. Keep in mind these cars generally were ran for 500,000 miles or more and were retired because of accidents.

So what does this all mean?

Please do not obsess about doing oil changes. Run them longer. You are likely only wasting oil and money. It is environmentally bad to change the oil too often. You are probably better off sending some oil off for analysis and learn when it is probably best to change your oil.
Question if you really need to spend the extra $$ on synthetic oils. If you do then you really should run them longer.

Spend some time looking for the opinions of oil engineers and what they know about oil in the boat engine. An opinion is not likely a good way to make a decision, best to find some facts. I am pretty sure boat engine oil is a science and not someones opinion.

[Penna]

I've got a related question. I have an old Volvo Penta M7a and do lake sailing for a short season. Probably run the engine for less than 15 to 20 hours during the summer/fall, then do a haul out for a very cold winter (Montana). I've been changing the oil once every summer when we put the boat in the water. Given the low hours, is an oil change necessary or advisable?

Thanks for any opinions.

[robdyson]

I ran my transit van for 10yrs and covered 200,000 miles, i did NO maintenance and it always started first time and ran sweet

[FlyingScot]

Yes, I think it is possible to change your oil too often. If you just changed the oil, when you start your engine you will have zero oil pressure for a second or two. This would create more wear than a typical startup. Obviously if you can prelube your engine before it fires up this would be better. It is also my understanding that synthetics 'stick' better and thus they are better during initial startup anytime, including just after you have changed the oil.

My Yanmar 3YM30 lists every 150 hours but only 100 for the sail drives (SD20). 100 hours doesn't feel like much time for gear oil. I check it weekly for contamination.

Having said this, I don't think anyone is likely to change their oil so often that it creates a real problem.

Side note: This brings back bad memories of hand cranking a prelube pump before starting a 1937 Fairbanks Morse 38 8-1/8 12 cylinder opposed 24 piston diesel. I have the USN to thank for letting me do this dozens of times, sometimes in the dark and wearing air mask (EAB). I never understood why I need to hand crank a non ergonomically designed handle over 100 times when we can't start the thing without air pressure. Of course the USN didn't care about my opinion or offer proper explanation.

[Carl-T705]

Check out Gulf Coast Filters, Inc. Specializing in Bypass Oil filters, Fuel filters, Hydraulic filters and Custom filtering for good info on oil changes. Engines that never reach oil temperatures of 190*F need more oil changes because impurities never get burned or boiled off. sailboat engines never reach this temperature in rawwater cooling and rarely in freshwater cooling. Motoryachts do.

I know a lady who buys a new car, a Camaro every ten years or so, she never changes the oil in them. She told me she changed the oil one time in a 90 something model and the engine blew up shortly thereafter. She has owned four of these cars, but most of her driving is trips of several miles. She adds oil when it is low, kind of shoots down oil changes every 3000 miles or the engine blows up.
I'm a skeptic... so I change the oil in my diesel truck every year or two about 200,000+ miles. It works for me, I've driven the same truck for 2,000,000 miles, but then, I run a Gulf Coast filtering system. change the gulfcoast every 15,000 miles and all oil filters every 30,000 miles. A friend of mine ( gulf coast user) changes his oil at about 500,000 miles, he's not a skeptic I guess.

[valhalla360]

Originally Posted by ShoreFun

I come from....

.....not someones opinion.

I think you would be very hard pressed to find a modern engine that failed due to oil changes being a bit over the recommended range.

I'd be willing to bet if you look at most "worn out" engines, you will find other major issues not related to regular oil changes as the main culprit (oil pump issues, plugged oil passages, low oil, rust during layout, etc...)

[FlyingScot]

Yes, I think it is possible to change your oil too often. If you just changed the oil, when you start your engine you will have zero oil pressure for a second or two. This would create more wear than a typical startup. Obviously if you can prelube your engine before it fires up this would be better. It is also my understanding that synthetics 'stick' better and thus they are better during initial startup anytime, including just after you have changed the oil.

My Yanmar 3YM30 lists every 150 hours but only 100 for the sail drives (SD20). 100 hours doesn't feel like much time for gear oil. I check it weekly for contamination.

Having said this, I don't think anyone is likely to change their oil so often that it creates a real problem.

Side note: This brings back bad memories of hand cranking a prelube pump before starting a 1937 Fairbanks Morse 38 8-1/8 12 cylinder opposed 24 piston diesel. I have the USN to thank for letting me do this dozens of times, sometimes in the dark and wearing air mask (EAB). I never understood why I need to hand crank a non ergonomically designed handle over 100 times when we can't start the thing without air pressure. Of course the USN didn't care about my opinion or offer proper explanation.

[kevinjilliana]

What is the cost of a few litres of oil compared to the cost of a replacement engine. The biggest risk with sailboat engines is lack of use and engine hours do not really apply. The condensation in the engine along with residual waste from the gases are the real problem. To get rid of all this corrosive s**t change the oil as often as possible. In my boat I change the oil every 12 months or 100 hrs whichever is the sooner. Oil Filter every second oil change. Genset same.

[parkstone bay]

You won't damage the engine by changing the oil too frequently. You CAN damage the engine by not doing it. As has been stated before, if you follow the engine manufacturer's recommendations - you know, it's called RTFM - that's a good start. All, well, ALMOST all, leisure marine engines die because of (a) lack of use, not over - use, and (b) lack of maintenance, not over-maintenance.

[Nicholson58]

Originally Posted by undercutter

Typical oil changes on the main engine are 200hrs. Shell R4 in the main engine and Shell R6 in the genset.

I have read that I could go 500 hours with these oils especially with the non egr main engine just changing the filters at 250hrs.

Input?

I installed Franz 1 micron bypass filters on the crankcase oil. I only change if I note a viscosity, pressure drop. 3 to 5 years. PCF also makes an equivalent filter. Over the road truckers use these for 100 to 300 thousand miles between oil changes. Centrifugal bypass filters are possibly better. Buying and disposing of 3.5 gallons for us per change in the Caribbean is prohibitive.

[a64pilot]

Originally Posted by Nicholson58

I installed Franz 1 micron bypass filters on the crankcase oil. I only change if I note a viscosity, pressure drop. 3 to 5 years. PCF also makes an equivalent filter. Over the road truckers use these for 100 to 300 thousand miles between oil changes. Centrifugal bypass filters are possibly better. Buying and disposing of 3.5 gallons for us per change in the Caribbean is prohibitive.

In your case, I’d think about a good high quality synthetic, and maybe oil analysis every so often to get an idea of how long should you run it.
Of course I don’t know how much of a pain it may be to mail in the oil for analysis