I am clueless

[coleslaw]

Well, not really, but I am having trouble balancing the logical, disciplined coleslaw against the emotional, superstitious coleslaw. I have a couple of diesel powered boats. The older boat has Cummins 5.9B diamond things, and I have been using Mobil Delvac 1 and Napa antifreeze and life has been good. The newer boat has a couple of Yanmar LP STE engines (Toyota, light weight, high output)and life has also been good. I am using the same Delvac synthetic and Napa antifreeze, the only difference is that the Yanmars specify 125 hour oil change vs Cummins 250 and coolant change annually vs. every 2 years. I don't care about that. . .I am not in to extended oil change intervals or saving a buck on antifreeze. I just want to take care of the engines so I can run the **** out of them when ever I feel like it. (I have been getting Blackstone oil tests at every oil change and they have been coming out just fine.) So, like a naieve jerk, I cruise the internet and I find that I am doing everything wrong. . .Yanmar's can't run on synthetic oil or green antifreeze. . .Cummins shouldn't have this or that. . .but I've been doing it and life is/was good until all these little paranoid guilt trips in cyberspace by the minions in the peanut gallery. What is real???

 

[Gurkha]

For internal combustion engines,only Mazda's rotary advices against synthetic due to some seal issues,no other reciprocating engines I know of recommend against using synthetic for any reason whatsoever,considering that you are using one of the ultimate in any oil(Delvac-I),diesel or gasser,that too with regular and not extended OCI,you really have nothing to worry about.

 

[Steve S]

Go with the manufactures recommendations .

 

[1040 WreckerMan]

I couldn't get a hold of our local Yanmar dealer, but I have worked on a few and never saw any cautions against synthetic. I also can not think of any reason why you couldn't run a syn oil, the LP STE is a new enough engine that seal compatibility should be a non issue. Two of the three that I was working on had synthetic oil. One had to have a warranty repair done and the Yanmar rep didn’t comment when looking at the UOA. I never specifically ask either since I didn’t think it would be an issue so don’t take that as being Yanmar’s official word I may have just dealt with a good rep.

As for coolant, there are a few seal issues there as well, but those were on older engines that converted to Long Life in some of its many forms. The only think I can see that may be a problem is the silicate levels and any additive they may be using. If they have an additive that was designed for a specific coolant, then running old green may in fact be a problem. As long as you flush the system very well when switching between coolant types you should have no problems.

If you are not leaking/burning/losing any coolant or oil and your samples (have you done a coolant sample?) come back good, run with your current practices and brands and have fun!

 

[coleslaw]

Thank's WM. . .That pretty much confirms what I thought. I have never done coolant samples as in sending to some lab. I do run oil analysis on engines and transmissions. So far, I've never gotten a bad one, but someday I suppose. . .

The internet is a great deal, but I suspect you could post all kinds of weird stuff and it would shortly circle the world and be close to undisputable fact by the time it came back around.