# What oil for Yanmar engine



## trantor12020

I've a Yanmar 2GM20F. I uses EssoMobil Delvac MX 15W40 API CH-4, CF-4 ...-4, SJ/CF grade. My engine manual states only CD grade. Do I suppose the later/higher grade covers all older ones ? I checked on Torresen's web and they sells Yanmar brand oil (p/n: 41540) with the above API CH-4, CG-4, CF-4, CF/SJ grades for use with 2GM20F (I assume since it appears in the filter page for 2GM20F).
However, when I read my friend's 3YM30 manual, it states that the YM engine should NOT use oil with CH-4, CG-4,...-4 spec as this would cause excessive wear to the valve train assembly. 
Now I'm uncertain if I should continue to use -4 spec oil for my 2GM20F for fear of same wearing on my engine. Any advise appreciated.


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## PBzeer

I use Chevron Delo in my 2GM.


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## theartfuldodger

The 3ym engine meets the 2010 emissions, so reason for different oil and if you notice the injectors are on the other side another improvement for good burn, have a new yanmar in my morgan and real good on fuel.


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## theartfuldodger

I should also say that I'm a deisel mechanic, both heavy equipment and marine, love working on the yanmar its a real toy


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## CalebD

Doesn't Rotella T cover most of the Cx Sx additives? Isn't this oil one of the best available?


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## theartfuldodger

Yes is the oil of choice for sure


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## billangiep

I also use the Chevron Delo multi-grade in my 3GM. I was informed by the dealer not to use this oil in the trans. They sugested a straight 30 weight non detergent to reduce wear on the cone.
Bill,


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## dvpamenter

I use Rotella T in my 19822 GM. Diesel mechanic recommended.
Don


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## theartfuldodger

The 3gm uses a different oil then the 3ym, and yes the gear box takes a different oil then the engine, and depending on the slope of the engine, one has to be careful not to over fill gear box and cause foaming, which was something I learned the hard way but caused no damage.


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## k1vsk

These recurrent debates about lube oil seem to never end. This time I'll take the liberty of making the only important point to eventually result - that frequent changes of the oil and filter are FAR more important than what brand you choose as they are almost all essentially equivalent.


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## trantor12020

I haven't seen Shell Rotella here in Singapore. We've Rimula (20W50) but Yanmar engine said its too heavy. I should go for 15W40. The only suitable 15W40 I found is the Esso Delvac MX. Although its spec CF covers my 2GM20F requirement of CD, I just wondering if the -4 spec could post a problem. But since Yanmar also market lube with -4 spec I suppose it should be ok for 2GM but maybe not for the 3YM20/30 series.


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## dave6330

Delo 400 for mine. PO was using it and I saw no need to change.


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## trantor12020

dave6330 said:


> Delo 400 for mine. PO was using it and I saw no need to change.


I see the Delo 400 multigrade is also the CI-4, CH-4 grade.
Then I believe the Esso Delvac MX should be ok as well since it also has similar -4 spec to Delo 400 and Rotella T.


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## pmesmer

I agree. Use a good Diesel oil and change frequently! You're good to go.


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## theartfuldodger

The oil for the 3ym30 must use Rottella as it is the only one which has zinc in it for the flat tappet use. If your engine is of flat tappet design you be sure that your oil has zinc in it, this is a must for warranty issues.


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## trantor12020

theartfuldodger said:


> The oil for the 3ym30 must use Rottella as it is the only one which has zinc in it for the flat tappet use. If your engine is of flat tappet design you be sure that your oil has zinc in it, this is a must for warranty issues.


What's a flat tappet ? I think the contact between the tappet and rocker arm is flat. That's where the gapping is done.


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## theartfuldodger

You asked what is a flat tappet, in the industry there are roller lifters and flat bottom liters, the kind in the 30ym is of flat bottom, the zinc is there to stop wear on the bottom with its contact with the camshaft. This prolongs the life of adjustment and wear. If you have ever had an engine a part and looked at the bottom of the lifter you would notice pitting and it has a hollow in it this is what the zinc is there for to help and prevent metal transfer. Hope this explains what you were asking.


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## trantor12020

theartfuldodger said:


> You asked what is a flat tappet, in the industry there are roller lifters and flat bottom liters, the kind in the 30ym is of flat bottom, the zinc is there to stop wear on the bottom with its contact with the camshaft. This prolongs the life of adjustment and wear. If you have ever had an engine a part and looked at the bottom of the lifter you would notice pitting and it has a hollow in it this is what the zinc is there for to help and prevent metal transfer. Hope this explains what you were asking.


Thanks. So the flat tappet is actually right in the gut of the engine. Since I've 2GM20F, I guess the zinc coating part doesn't concern me. Hence the CI-4 CH-4 CG-4 spec is not a problem to GM series. The YM series users would probably have problem getting their correct multigrade engine oil in future as more lub goes -4 spec.


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## theartfuldodger

"Trantor", was wondering what your knowledge of engines might be, as the gut as you call it is know as the valve train, and as besides the tappets, crank shaft, and rod bearings are subject to the same type of wear, the zinc is there to aid against premature wear, as wear occurs about 80 per cent of the time in start up. As for the zinc it is in Shell Rottella 15w40 oil. I might pass on one more thought, when one does an oil change and if after the start up you happen to check the oil level and the oil is black count that as a very good thing, as the oil is removing the hydro cabrons and doing its rightful job. A clean oil in the crank case is not doing a good job


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## trantor12020

theartfuldodger, I know engine but don't know enough to know that those are call valve train. glad to learn new things everyday. also glad to know that black oil means good sign. was wondering why the oil turns black shortly after change, even after flushing with new oil and replaced filter. Ok, so the zinc is in the oil and not on the tappet and components? I'm alittle confuse here. The 3YM30 manual specifically state that oil with CI-4, CH-4, CG-4 spec should never be use as this will cause high wearing in the valve train. This is not mention in the GM series manual, could it be because when the GM was design, those -4 spec oil hasn't been formulated yet?


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## theartfuldodger

This is all in the name of emissions. The engine builders have to inprove power plants to meet emission standards proposed by our governements. And so it is with the changes to the engine "ie" metal composites, complete burn designs, electronics are just a few. The 30ym is such an engine, and one real sign is the location of the injectors between a 30gm and a 30ym, they are on opposite sides, and I believe it is for a better burn. The engine is running at a higher rpm. Myself with having my engine 30ym now for two years have made some changes as well with timing and valve clearences as a few. This year going to try pre warm the fuel as is done in the auto industry. There is one thing which I've never heard much of in the marine industry is engine run away. With the increase in engine rpms wondering if this is going to show its face as it does in the auto industry.


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## Northeaster

I noticed Rottela oil, at Hamilton Marine, while on a road trip, so I bought some. Noticed later, that it is SAE 30, not 15W30, or 15W40. 

Is the SAE 30 Ok for an older Yanmar 2GM, or should I buy something else?

Also, is it Ok for the 2GM trannie as well?

PS I aware of the general need for different weights / vicosities, during warmer summer / colder winter, etc, just not sure what my engine needs!!

Thanks!!


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## JohnRPollard

theartfuldodger said:


> The 3gm uses a different oil then the 3ym, and yes the gear box takes a different oil then the engine


The manual for our Yanmar 3GM30F explicitly states that the transmission uses the same oil as the engine. In the quote above, are you referring to the 3GM transmission, or the 3YM transmission? What is the source of your information? Thank you for a clarification.


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## Rockter

Any decent diesel 10W/40 motor oil will do it.


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## JohnRPollard

Northeaster said:


> I noticed Rottela oil, at Hamilton Marine, while on a road trip, so I bought some. Noticed later, that it is SAE 30, not 15W30, or 15W40.
> 
> Is the SAE 30 Ok for an older Yanmar 2GM, or should I buy something else?
> 
> Also, is it Ok for the 2GM trannie as well?
> 
> PS I aware of the general need for different weights / vicosities, during warmer summer / colder winter, etc, just not sure what my engine needs!!
> 
> Thanks!!


Straight 30W is fine for your engine, but if you are in a cold climate it might be preferable to have a multi-weight oil like 10-30. Likewise, in a hot climate 15-40 would be preferable. All are acceptable for your engine.

Unless you are in a very hot climate, I would just go ahead and use the straight 30W this time, and switch to whatever weight is best for your climate on the next oil change. Like Rockter said, 10-40 is usually a safe bet almost anywhere.

Our Yanmar manual indicates that the 1GM, 2GM, and 3GM all use the same oil in the transmission as in the crankcase.


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## Rockter

In motorcycles, motor cars and boat engines, it is so difficult to know what the difference in performance is anyway.
How do you call that one, 30 years on.


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## TSOJOURNER

*Mobil Delvac Super 1300 15W40 ?*

Hello everyone!
I have Yanmar 2GM 1981 and going to change oil.
Can I use Mobil Delvac Super 1300 15W40 diesel oil?
Thank you


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