Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 14-01-2017, 12:23   #1
Registered User

Join Date: Nov 2012
Location: Used to be San Francisco Bay, now PNW
Boat: Catalina 320
Posts: 299
Shell Rotella T6 5W-40 Full Synthetic Diesel for Yanmar 3GM30F

Ahoy sailors,

Hopefully a simple question for those who know what this is all about. I am about to change oil for my 3GM30F Yanmar and was looking in what to use. I am not sure what all those numbers mean on oils

Is Rotella T6 5W-40 Full Synthetic Diesel good for it? I read in the forums that full synthetic might be an overkill for old engines but I don't mind an overkill as long as it doesn't hurt the engine.

I would rather go with a robust oil and pay a bit extra than have doubts.

Any recommendations?

P.S. If it matters at all, boat is in San Francisco Bay.
__________________

Tenedos is offline   Reply With Quote
Old 14-01-2017, 12:32   #2
Registered User

Join Date: Apr 2012
Posts: 585
Re: Shell Rotella T6 5W-40 Full Synthetic Diesel for Yanmar 3GM30F

That oil would be fine, but non-synthetic Rotella T 15W-40 is great oil at lower cost. I have used it in my Yanmar engines for over 30 years...and my original 41 yo Yanmar is still running fine on it.
__________________

fryewe is offline   Reply With Quote
Old 14-01-2017, 12:42   #3
Registered User

Join Date: Nov 2013
Location: Slidell, La.
Boat: Morgan Classic 33
Posts: 2,098
Re: Shell Rotella T6 5W-40 Full Synthetic Diesel for Yanmar 3GM30F

If the engine was broken in with full synthetic go for it. If not, or if you don't know, best to stick with regular 15W-40 Rotella. I doubt you're trying to meet any EPA mileage requirements...
jimbunyard is offline   Reply With Quote
Old 14-01-2017, 12:47   #4
Registered User

Join Date: Nov 2012
Location: Used to be San Francisco Bay, now PNW
Boat: Catalina 320
Posts: 299
Re: Shell Rotella T6 5W-40 Full Synthetic Diesel for Yanmar 3GM30F

Quote:
Originally Posted by jimbunyard View Post
If the engine was broken in with full synthetic go for it. If not, or if you don't know, best to stick with regular 15W-40 Rotella. I doubt you're trying to meet any EPA mileage requirements...
Thanks Jim. I don't know if there was synthetic oil in before but I doubt it. I believe you are not supposed to go from synthetic to regular though?
Tenedos is offline   Reply With Quote
Old 14-01-2017, 12:50   #5
Registered User

Join Date: Apr 2006
Posts: 4,413
Re: Shell Rotella T6 5W-40 Full Synthetic Diesel for Yanmar 3GM30F

Quote:
Originally Posted by fryewe View Post
That oil would be fine, but non-synthetic Rotella T 15W-40 is great oil at lower cost. I have used it in my Yanmar engines for over 30 years...and my original 41 yo Yanmar is still running fine on it.
If you can believe this... and it's seems totally weird... but I found a full 5 gallon pail of it... unopened... right in front of my apartment building. WTF??????????

It was like a gift from the heavens.. exactly what I use!
Sandero is offline   Reply With Quote
Old 14-01-2017, 12:52   #6
Registered User

Join Date: Apr 2005
Location: Southern California
Boat: Catalina 320
Posts: 757
Re: Shell Rotella T6 5W-40 Full Synthetic Diesel for Yanmar 3GM30F

Shell Rotella and Chevron Delos have been the preferred oils for diesels for decades, I find that straight 30 wt. works fine in our non-freezing not very hot climate.
My 320 is an '02 I brought down to San Diego from San Francisco about 6 years ago.
Calif.Ted is offline   Reply With Quote
Old 14-01-2017, 13:31   #7
Registered User

Join Date: Jan 2013
Posts: 112
Re: Shell Rotella T6 5W-40 Full Synthetic Diesel for Yanmar 3GM30F

As said before, do not use synthetic unless engine has been run full synthetic since break-in. Multigrade 5w-40 rotella is what Yanmar recommends for non turbo models. Strait grade only for everything with a Turbo.
HBWT is offline   Reply With Quote
Old 14-01-2017, 15:28   #8
Registered User

Join Date: Nov 2012
Location: Used to be San Francisco Bay, now PNW
Boat: Catalina 320
Posts: 299
Re: Shell Rotella T6 5W-40 Full Synthetic Diesel for Yanmar 3GM30F

Thanks everyone. I ordered a 15W-40. Will change next week.
Tenedos is offline   Reply With Quote
Old 15-01-2017, 09:41   #9
Registered User

Join Date: Mar 2012
Location: Fort Pierce, FL
Boat: Hunter, Legend, 35.5
Posts: 14
Re: Shell Rotella T6 5W-40 Full Synthetic Diesel for Yanmar 3GM30F

While you're out shopping for Rotella T, see if you can figure out the difference between Rotella T and T4. Shell's website indicates T4 meets newest API standard and I've got an idea that T4 is replacing T on the shelves but no ironclad proof yet. We've still got a gallon or so of T left for our 3GM30F which seems to take about 3 quarts using an extractor thru the dipstick port and changing the filter!
Laser fun is offline   Reply With Quote
Old 15-01-2017, 10:56   #10
Registered User

Join Date: Feb 2015
Location: Rappahanock River, Va
Boat: Caliber 47
Posts: 180
Re: Shell Rotella T6 5W-40 Full Synthetic Diesel for Yanmar 3GM30F

Just curious guys. You who suggest don't go synthetic if motor wasn't broken in with it. Why not? I can find no correlating info on this subject on any web site.

Synthetic had been proven in test after test the superior lubricant. If I had the choice I'd use synthetic every time.

Greg
SV Ti Amo
Caliber40 is offline   Reply With Quote
Old 15-01-2017, 11:05   #11
Registered User

Join Date: Mar 2016
Location: Hopkinton, MA
Boat: Hunter Legend 35.5
Posts: 42
Re: Shell Rotella T6 5W-40 Full Synthetic Diesel for Yanmar 3GM30F

The warning not to switch fr syn to conventional has been around since syn came out. It's personal preference as far as I can tell. I've switched well run multiple car & boat engines to syn w/ no Ill effects. Yes it's more money. But in the context of overall cost of ownership, not much. In a perfect world, it really isn't necessary. I share the world I live in with Murphy however, so a little extra heat resistance is worth it to me. Of course, Im probably the only one who's ever heard his temp alarm go off..
TommmD is offline   Reply With Quote
Old 15-01-2017, 11:27   #12
Marine Service Provider

Join Date: May 2011
Location: PDX
Boat: Gulfstar 50
Posts: 1,812
Re: Shell Rotella T6 5W-40 Full Synthetic Diesel for Yanmar 3GM30F

Quote:
Originally Posted by Tenedos View Post
Thanks everyone. I ordered a 15W-40. Will change next week.
Get a hold of Blackstone and send them a sample of the old oil. They will test it and tell you what type of oil (Dino or synth) and tell you what metals etc are in the oil.

This will establish a baseline on the condition of the engine.

Blackstone Labs



Just a happy customer....
evm1024 is offline   Reply With Quote
Old 15-01-2017, 11:32   #13
Marine Service Provider

Join Date: May 2011
Location: PDX
Boat: Gulfstar 50
Posts: 1,812
Re: Shell Rotella T6 5W-40 Full Synthetic Diesel for Yanmar 3GM30F

One more thought Rotella and Delo are intended for diesel engines specifically. Best to stay with an oil designed for Diesels.

Diesel Engine Lubricating Oil
^.......^........^.............^
evm1024 is offline   Reply With Quote
Old 15-01-2017, 11:39   #14
Registered User

Join Date: Nov 2013
Location: Slidell, La.
Boat: Morgan Classic 33
Posts: 2,098
Re: Shell Rotella T6 5W-40 Full Synthetic Diesel for Yanmar 3GM30F

Quote:
Originally Posted by Caliber40 View Post
Just curious guys. You who suggest don't go synthetic if motor wasn't broken in with it. Why not? I can find no correlating info on this subject on any web site.

Synthetic had been proven in test after test the superior lubricant. If I had the choice I'd use synthetic every time.

Greg
SV Ti Amo
Because you didn't look very hard?

From the fifth listing on the first page of a google search. It's just a magazine article so you're on your own in trusting it's veracity.

"Synthetic oils may not be ideal for a vehicle that has high mileage (engine hours) and has only used mineral base oils during its lifespan. If you were to change the oil to a synthetic in this type of vehicle, it could lead to a number of problems. The oil’s natural detergent action could wash off varnish and other soot deposits that are sometimes left behind with certain mineral oils. This action of cleaning deposits off cylinder walls not only can cause the engine to use more oil but also can reduce cylinder wall thickness and allow small amounts of oil to bypass the piston rings and burn up in the cylinder head."

When to Choose a Synthetic Lubricant

I tend to trust, and recommend, what has worked for me in the past, and is working for me now. I use 20W-50 in my gas engines and 15W40 in diesels. I hear way too many rattly-ass-top-and/or-bottom-end-on-startup 'modern' engines to have much faith in 5w-20 oil, but hey, to each his own...
jimbunyard is offline   Reply With Quote
Old 15-01-2017, 11:42   #15
Registered User

Join Date: Nov 2010
Location: BC
Boat: O'Day 40
Posts: 608
Re: Shell Rotella T6 5W-40 Full Synthetic Diesel for Yanmar 3GM30F

I was in the service end of business for 40 odd years and heard this warning a lot. The only time I saw a problem was a gas engine that hadn't had an oil change in at lease 30,000 miles. The high detergents in the synthetic pulled all the sludge up from the pan and plugged up the oil galleries with "interesting" results.
If the engine oil system is in reasonable condition I'd only use the synthetic if it was the same price. Synthetic really only has 1 advantage. It stays thinner at cold temperatures so you get faster lubrication on start up. Really only important at well below freezing.
__________________

__________________
Trying to make new mistakes.
bcboomer is online now   Reply With Quote
Reply

Tags
3gm, 3gm30, diesel, rot, yanmar

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Samson C-Shell 36 mjt Monohull Sailboats 46 08-10-2015 23:10
Sampson C- shell TonyQld Monohull Sailboats 3 27-05-2012 13:24
For Sale or Trade: Hard Shell Rowing & Sailing Dinghy - Outboard Available Dulcesuenos Classifieds Archive 4 13-03-2012 06:57
Tee on the Half Shell? Surf City Construction, Maintenance & Refit 4 02-11-2009 20:56
White Shell II luepetri Meets & Greets 3 29-08-2008 20:09

Advertise Here


All times are GMT -7. The time now is 13:12.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.