Oil Change Frequency

Feb 24, 2014
24
Hunter 376 Havre de Grace
Seeking opinions at my own peril. How often (hours) are you changing the oil in your diesel motor? I'm running an Yanmar 3JH2E and have been changing the oil at 50 hr intervals. Seems excessive. The operators manual calls for 1st change at 50 hrs and 150 hrs thereafter. Granted, its a lot to get 50 hrs in a sailing season unless long trips are involved. I would change the oil before winter lay up regardless of hours. Its August, I've got just over 50 hours on this oil, plan to haul in October ... seems like a waste to put a couple dozen hours on fresh oil then change again for winter storage.
 
Feb 5, 2004
3,739
Tartan 3800 Westport, MA
I think 50 hrs. is excessive. Why would you change at 50? Are you using regular or synthetic?

With the use my boat gets, once a year oil changes are fine. I get an oil analysis, too.
 
Feb 8, 2014
1,084
Columbia 36 Muskegon
50 hours does seem excessive after the initial break-in period. Most of the recommendations I've seen were 100 hours. With our short sailing sailing in Michigan, most around here change in the fall regardless of hours.
 
Sep 25, 2008
380
Catalina 30 MKIII Varuna Boat Club
Hi, Since I only put about 30 hours per year on my Universal 25xpa and am using a synthetic blend, my usual once a year oil change far exceeds manufacturer's recommendation. Once a year is for my peace of mind and not going to break the bank. Happy Sailing.
 
Aug 15, 2019
1
Hunter 36 Selah Bainbridge Island
Seeking opinions at my own peril. How often (hours) are you changing the oil in your diesel motor? I'm running an Yanmar 3JH2E and have been changing the oil at 50 hr intervals. Seems excessive. The operators manual calls for 1st change at 50 hrs and 150 hrs thereafter. Granted, its a lot to get 50 hrs in a sailing season unless long trips are involved. I would change the oil before winter lay up regardless of hours. Its August, I've got just over 50 hours on this oil, plan to haul in October ... seems like a waste to put a couple dozen hours on fresh oil then change again for winter storage.
You have the right attitude and plan.
 
Feb 5, 2004
3,739
Tartan 3800 Westport, MA
Hi, Since I only put about 30 hours per year on my Universal 25xpa and am using a synthetic blend, my usual once a year oil change far exceeds manufacturer's recommendation. Once a year is for my peace of mind and not going to break the bank. Happy Sailing.
Wondering about your decision to go to synthetic blend, at only 30 hours a year. Could be "no reason," but I'm just curious as to the reasoning, if any. Should I go to synthetic, or blend? I'm doing about 140 hours a year.
 
Feb 14, 2014
3,887
Hunter 430 Saba Waveland, MS
I inspect my oil to see if it is becoming dirty or I change seasonally.

I looked in March and the oil is clear, engine hours since last change ≈100 hrs.
I converted to full synthetic 4 years ago. All is good and less carbonization, by my inspection only.
Jim...
 
Feb 14, 2014
3,887
Hunter 430 Saba Waveland, MS
Mine almost instantly turns black!
Sounds like you have an engine problem to me.

Mine was clear and I compared it to fresh synthetic oil. Looked the same, nice and clear.

I assume your BLACK is carbon black.

Tip: Put some of your BLACK'nd oil on a white paper towel. Let the oil spread and leaves mainly the BLACK'nd area.
The wipe the up BLACK with thumb and a finger. Rub them, if it is Carbon Black, it will stay in your finger pores.

Jim...
 
Jun 11, 2011
1,192
Hunter 41 Lewes
I rarely have more than 50 hours on my oil due to the sailing season length. Right now there's only around 5 hours on the motor since the last oil change. But that change was at the end of last season. The oil is still golden, slightly tinted. We'll be off to Block Island in a few weeks and I will change the oil and primary fuel filter before we leave regardless of hours. At the end of the season I'm taking her south to Charleston SC. I will change both again just before that trip. It's cheap insurance/ peace of mind. My oil doesn't get dark until around 20 hours. I use Rotella T by Shell. Mother's milk for diesel engines. I try to use the OEM filters for everything.
 
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May 20, 2016
2,795
Catalina 36 MK1 Everett, WA
100-150hrs and in Nov/Dec. Transmission every other oil change except also winter change. I also sen oil for analysis.
 
Feb 10, 2004
2,953
Hunter 40.5 1997 h40.5 Bristol, RI
I put about 130 hours on my auxiliary and about 150 hours on my genset each year. I change the oil and filter once per year at the beginning of the winter layup. I use only conventional oil- Rotella 15W-40 in my Auxiliary and 30W in my genset. The only time I have done an in-season oil change is when I have done an extended cruise and rolled on 300 hours on the engine. That was just one time.

I would urge caution in changing to syntetic oil. I did so in my car and promptly had costly oil leaks to repair. I then read where oil leaks are more likely with synthetic vs conventional. Now you tell me. So I went back to conventional in my car and I won't begin to consider synthetic in my boat. Do some research before you switch. As always, YMMV.