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Kon Tiki

Member
Oct 24, 2008
40
Pocasset Ma
Boat Info
Sedan Bridge - 3126 Cats
Engines
3126 Cats
Hey guys,
Here is my story, last year really didn't use the boat at all. Spent a lot of money on the boat, refreshed the cooling system, new hoses, dipped the heat exchangers and installed hard wood floors. However, after much Business travel and other things going on I logged about 25 hrs of engine use. Please note about 5 of those hours burping the engines with new cooling juice, warm ups and so forth.

Here is the question, since I didn't change the oil last fall, do I change this spring. In fact my air spes still have visible oil on the outside from last spring.

Please send in your vote!

Thanks,
Pat
 
I say yes. I was told long ago that the hydrogen by product of combustion makes the oil acidic which over time is not good for the engine. Even if it looks clean, the ph is probably off.
When in doubt, change it out!!


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Changing yearly is prudent but I see no real issue with going another year. I know a guy with the same boat that has samples done every year and only changes it when advised to. 4 years on the same oil without too many hours last time we spoke.
 
I'm just making an observation that a lot of the responses are from gas engines owners and they might not realize that 3126's hold 6 to 6.5 GALLONS per engine.... But still oil is cheaper then 2 engines.
 
Personally, I would have changed it at the end of the season to avoid having the contaminants sitting there all winter. But, I would definitely change it now to play it safe. Oil is one of the cheapest investments in maintaining your very expensive engines! Change the oil and filters and try to enjoy her more this year than last!
 
I'd suggest taking oil samples of the engines, trannies and genset to a CAT dealer to have them analyzed. First of all, the oil may not be bad, and an analysis will tell you that. It also will tell you what the specs are now and you can use that as a reference point going forward.

If the analysis points out areas that are out of whack then you should change the oil. In a recent article by Steven D'agostino, an expert boat mechanic and author of a monthly article in PMY. He suggests that instead of getting oil changes on a regular basis that the skipper send in oil samples on a regular basis. The main reason for this is that in most boats they don't get enough hours in a year (or two or three) to justify changing the oil, especially in a diesel with a large oil capacity. Annual oil changes when they're not necessary waste a lot of oil, not to mention the expense of the oil and filters. (filters for my boat run in the $40 each range.)

So Pat, I suggest you get some oil sample bottles from your local CAT dealer, take the samples when they're warm, and send them in to be analyzed. Get samples from both engines, both trannies and the genset. The sample bottles come in a postage prepaid shipping container.
 
Kon Tiki said:
Hey guys,
Here is my story, last year really didn't use the boat at all. Spent a lot of money on the boat, refreshed the cooling system, new hoses, dipped the heat exchangers and installed hard wood floors. However, after much Business travel and other things going on I logged about 25 hrs of engine use. Please note about 5 of those hours burping the engines with new cooling juice, warm ups and so forth. Here is the question, since I didn't change the oil last fall, do I change this spring. In fact my air spes still have visible oil on the outside from last spring.

Please send in your vote!

Thanks,
Pat
Click to expand...

Pat, I tend to be a pretty conservative guy & do believe these engines require clean oil, fuel and air, but I also believe they are a lot more rugged then we appreciate. More than one very knowledgeable mechanic has suggested that oil changing intervals be done based on cumulative fuel burn since the previous oil change. The theory being that since the "contaminants" are both a function of combustion by-products and friction (more-so than calendar days), and total fuel consumed should correlate strongly to total engine RPM's since the last oil change. In my mind this also makes the oil analysis more meaningful when comparing current data to previous data since there are less variables. Under this scenario, I think, based on usage, driving habits, etc. it's and individual decision to determine what would be the most appropriate fuel consumption value your most comfortable with.

I realize living in Fla. and having a year round season, I don't have to confront having "used" oil just sitting in the sump for an extended period. However, in your particular case, it seems you have already crossed that bridge.

I have heard the acidity argument before, but I find it interesting that pH is not one of the parameters Cat checks as part of the SOS program.

Just my $.02, in the end, do whatever will let you sleep better!!

Good luck, Art
 
2012 was our first full season on a 2000 410DA with low hour 3126s. When we purchased the boat in August 2011, there were too few hours (<10) on that oil change to provide a meaningful oil analysis. The seller was an aging man with health issues, the oil had been last changed the previous fall during winter layup.

Had the aftercoolers hot tanked during winter layup, and changed the oil in the spring - but because the oil was a multi-viscosity Rotella, and I wanted straight weight Delo30 in the engines as CAT calls for. If not for that fact, I would have run the boat all last season before changing.

By the end of this season, (about 70hrs) the oil had just gone from clear honey colored to slightly opaque in translucence, indicating good combustion on both sides with minimal sooting taking place. The inside of these engines must be incredibly clean.

My plan is to take an oil sample this spring, and if all comes back good, run this oil for at least 200hrs. We are headed to Seattle with the boat in June, so there won't be any fall layup to trigger a change, just hours on the meter.

My .02 worth.
 
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Do any of you guys see the condensation on the outside of your engines during periods of cold nights and reasonably warm days?

Well, those same moisture droplets are on the inside surfaces too. Nobody mentioned removing trapped moisture as a reason for changing the oil annually, but that, along with combustion by products, is why Cat (in this case) says to change the oil "every 250 hours or annually, whichever comes first."
 
fwebster said:
Do any of you guys see the condensation on the outside of your engines during periods of cold nights and reasonably warm days?

Well, those same moisture droplets are on the inside surfaces too. Nobody mentioned removing trapped moisture as a reason for changing the oil annually, but that, along with combustion by products, is why Cat (in this case) says to change the oil "every 250 hours or annually, whichever comes first."
Click to expand...

No arguing the spec, Frank. My situation is this - prior to putting the boat up last fall, the boat was run ~60 miles on plane from our marina to the storage location. The boat was hauled and moved into a heated, climate controlled building that does not vary in temperature. Zero condensation. I can't see water remaining in the oil after a two+ hour run, and I can't see any being added to the oil while stored in this environment. Boats used lightly, living in the water year round, with widely ranging water vs. air temps, rain, humidity, etc. may well be a different story.
 
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