“Opinions” on oil change intervals

[madhatter1]

“Opinions” on oil change intervals

Yeah, I’m asking for it. Opinions on hours to change oil and on Detroit’s and Onan generators. Capt Dave did the mains every 50 hours. Genny I’m not sure, but probably the same time as he did not anchor out like we do so genny matched hours on the mains. These days the generator has 600 more hours that the mains.

I have been doing the mains at 100 hours and generator at 150 hours. Generator gets Rotella T-5 and a good filter. The mains I use Napa diesel oil and the Detroit filters. Toying with the idea of sticking with the 100 hours in the mains to do oil and filters but halfway pull out 5 gallons out of the pan and throwing in 5 gallons fresh. How Han that not hurt and and maybe help out? Trying to only do full oil changes during the cooler months.

Generator gets changed based on hours regardless since we use it a lot. But then again a midway change of just oil couldn’t hurt, right?

I asked for opinions so I opened myself up to whatever responses. I can sort through responses to figure out what I want to do moving forward.

 

[Sadey]

Re: “Opinions” on oil change intervals

I’m a total newb but I do both every 100 hours, trans every other change. Rotella with Napa Filters. I run the mains on one Racor then switch at the oil change and change the used one. That is unless I need to switch earlier due to contamination. Been lucky so far. The boat lives in Wisconsin and it usually works out the change happens around the fall before the long winters nap. If not, I wait until the 100 hour mark. Samples every change. That’s how the pro captain handed the boat to me so she’s used to it. 3700 hours on 892s and so far no issues.

 

[Pascal]

Re: “Opinions” on oil change intervals

Unusually follow the manufacturer recommendations in the manual.

On gens weather onans, NL or Norpro it’s usually 200-250 hours. I also replace the racor and the secondary at every oil change unless we re in the Bahamas as I don’t want to risks a priming issue over there. I then replace the fuel filters when we get back

For the mains, it varies by manufacturer. With big Cats (3412s and C32s) I used to do it around 200/225 hours. The MTUs I run now (16V2000) 150 hours is the max recommended

 

[Captain Ralph]

Re: “Opinions” on oil change intervals

What does the factory manual say? Start there.
Hard/hot operating conditions, sulfur in the fuel, change oil a lil sooner.
Easy operating conditions, maybe a lil longer.

The T5 in the gen-sets is a great idea. We always felt it offered a bit more protection in case of Murphy Attacks..
Our best bud went further to full synthetic for both of his NL sets.
NL recommends 200 hour oil service. He may push 250 hours but that is darn nice oil coming out.

My older Kubota and Isuzu gen-sets have been on T5 15w40 most their lives.
Just now using all synthetic in the smaller Kubota. Oil labs come back perfect.
Easy lives, up to temp, nice load, I exceed 250 hours (300 hours) some times.
Oil filters on my gen-sets get changed every other oil change. Fuel filters as needed.

One of the HOF members uses synthetic oil in his Detroit. I am excited about trying this but after a couple of years now, I still have not done it yet.
The NAPA CF-2 (75-118 - Valvoline ) has always worked great. Our 45 year old Detroits and I have developed a good bond these near 20 years of owning them.

DDC recommends 150 hour oil and 500 hour filter changes.
All of our oil and oil filters are changed about 200 to 250 hours. Fuel filters may be changed at the same time but usually as needed.
Our friend used T1 but now Miles oil. Changes all by 200 hours.

So I push the hours a good bit, Our best friend pushes the hours just a bit. All labs come back great.

Oil labs can offer lots of help. We use the Cat labs.

 

[Briankinley2004]

Re: “Opinions” on oil change intervals

I usually do mains at 100 hours and generator at the same time. I find the generator has more hours then mains at that point but isn't quiet as sensitive to oil quality as the Detroits are. I think if you follow manufacturer's recommendations on any of them you should be fine.

 

[jmooney]

Re: “Opinions” on oil change intervals

I don’t put much time on our boat , so even if the hours are low , I don’t let more than a year go by before I change the oil in the mains and generators. I change fuel filters at this time . I have been told that changing transmission oil every other oil change is okay.

 

[Dan Mapes]

Re: “Opinions” on oil change intervals

Pull an oil sample from them and see what the examination says. Blackstone would tell us we could extend it if we wanted to. Usually changed the oil about every hundred hours but I usually did it after the annual trip to the Bahamas since we traveled slow only running them up once in a while. When we sold it the mechanic pulled the airbox covers and they were well goobered LOL.