Oil weight question.

[Chris & Lenore]

He previous owner has been using SAE 30 non-detergent, API SL oil in the engine (Yanmar 3GM30F). According to Yanmar, it has a recommended temp range of 50 to 90 degrees and usable up to 100. The low end concerns me as the first and last month of our season often sees temperatures around the freezing mark. I did my end of season oil change last weekend and the new oil was the consistency of corn syrup. Ambient temp was about 40 degrees. Took forever for it to go down the funnel...

The Yanmar chart shows 20W40 being a better choice - 20 to 100 degree range. Actually, it appears that 15W40 is the common type. And not synthetic (everyone seems to agree on that, at least for a Yanmar).

Is there any reason I should not switch to 15W40? And one with API CH-4 or CI-4 designation (they replace CD type which was what the Yanmar manual specified).

Wish I thought of this before I changed the oil last weekend, but I'd gladly change it again if it means a longer lasting engine.

Thanks,

Chris

 

[centerline]

you have cold start up in the lower temps, but once the engine gets to operating temperature, the engine "room" temp will climb into the range well withing the operating range of the oil... and there is a bit of varience on either end of the "temp range" scale.

myself, I am a believer in chevron/delo oils, and even though the multi-vis oils can allow better fuel "mileage", they are more prone to breaking down earlier than is a straight viscosity oil. this only means timely oil changes are more important....
with the fact that most sailboat engines are started and shut down many times without becoming warm enough to evaporate any condensate it picks up, its a seriously important thing to change the oil at least as often as the manual suggests for the application.

I have stayed with my 30wt oil just because that is the recommendation in the manual, but I am considering switching to a multi-vis also... with the quality of the modern multi-vis oils, there really is no good reason to keep using the straight 30wt except for the reason that the 30-40 year old manual says to use it

 

[Anonymous 121765]

Chris,

To me, you answered your own question. If the manuf. says to use 20w40 or 15w40(?), that's what you want to use. Different locations/temperatures have specific oil grades.

My best suggestion is NOT to overthink it pal. Check your area temp ranges & pick the best weight oil for your area. It's not a watch, it's only a diesel.

CR

 

[kloudie1]

One of the "name" diesel oils like Delo or Rotella T, or Mobil Delvac in the 15-40 grade is perfect for your Yanmar. I'd not go with a synthetic, just the good old dino oil. The stuff cleans and prevents deposits .. This new blend diesel oil is lots better than the one that Yanmar specified way back then.. The new straight grades are too, but the 15-40 is fine..

 

[Eddie7045]

Most of what I whave learned about engines

over the last 50 years was debunking myths about them by shade tree mechanics. If it was me I would completely disregard what the previous owner did and follow the engineering specs. I remember when multi-viscosity oil first emerged. For decades after old timers would swear that straight weight oil was better. Expert advise and my own experience proved otherwise. I can't understand why he would use non-detergent oil either although I've heard that one before too. Modern oils contain a precise package of additives including, corrosion inhibitors, anti-wear agents, anti-foaming agents and detergents that hold contaminants in suspension until it is changed. All this promotes long engine life. Another wise practice is frequent oil changes. It never ceases to amaze me to what lengths people will go to avoid doing it. Another one is using oil that is heavier than is specified. Seems to be some kind of macho thing about heavier being better.

Trust the engineers on this one.

 

[Chris & Lenore]

Ha, I do the to overthink these things...

I guess my main concern was the API designation of the previous owners oil. It's not diesel. His stuff was half the price of the "diesel" oils (I'm sure that's why he used it).
So I might just change what's in the crankcase to a diesel 5W40 and be done with it. I agree with the comments about changing it when the manufacturer recommends. Always done that with my cars - put on tons of mileage and never an engine issue.

Chris

 

[Eddie7045]

Oh, yeah, "I've used (brand X automotive oil) in

my Buick for 20 years", as they're pouring it into their Volvo diesel. I've heard that one also. Not surprising to me anymore.

 

[RIVERCRUISER]

One would have to be a total id**t to use non-detergent oil in a modern diesel engine!!!

I use Rotella 15W40 year round in every engine I operate (except my wife's VW TDI) in warm and cold climates. IE: FLA, VA and PA.

You should switch to the proper oil immediately installing a new filter.

Personally, I would run it a few hours and then change the oil AND FILTER again. Try to get in a long run at normal operating RPM and temps prior to the oil change. Then you should be able to go to your normal interval between oil changes.

 

[RIVERCRUISER]

over the last 50 years was debunking myths about them by shade tree mechanics. If it was me I would completely disregard what the previous owner did and follow the engineering specs. I remember when multi-viscosity oil first emerged. For decades after old timers would swear that straight weight oil was better. Expert advise and my own experience proved otherwise. I can't understand why he would use non-detergent oil either although I've heard that one before too. Modern oils contain a precise package of additives including, corrosion inhibitors, anti-wear agents, anti-foaming agents and detergents that hold contaminants in suspension until it is changed. All this promotes long engine life. Another wise practice is frequent oil changes. It never ceases to amaze me to what lengths people will go to avoid doing it. Another one is using oil that is heavier than is specified. Seems to be some kind of macho thing about heavier being better.

Trust the engineers on this one.

Wut he said!

 

[hewebb]

I agree with rivercruiser. Changing to 20W40 may loosen a lot of sludge build up from the use of non-detergent oil.
I have been using Shell Rotella multi grade in diesel engines for years.

 

[Claude L.-Auger]

I'm in Montreal so same type of outside temps as you. Maybe worst ! Like many here, I also have been using Rotella T 15W40 in my Yanmar 3GM30F for years. Never any early or late season difficult starts. If your boat already on the hard, then I'd wait until Spring, run the engine under load long enough to get it warm, then change oil and filter. As suggested in a previous post, I'd run some hours then change again to make sure I get rid of oil sludge new oil is likely to disloged.

 

[Chris & Lenore]

I'm in Montreal so same type of outside temps as you. Maybe worst ! Like many here, I also have been using Rotella T 15W40 in my Yanmar 3GM30F for years. Never any early or late season difficult starts. If your boat already on the hard, then I'd wait until Spring, run the engine under load long enough to get it warm, then change oil and filter. As suggested in a previous post, I'd run some hours then change again to make sure I get rid of oil sludge new oil is likely to disloged.

I'd say worse - lived in Montreal for 3 years about 15 years ago. Still haven't thawed out

I have a few days until haul out so I'll definitely do another oil change to the Rotella T 15W40 - followed by another change after a few hours use in the spring.

Another question - what filter do you use? The previous owner used a Fram PH6607. I don't see "diesel specific" filters, so I'm hoping this one is OK.

Chris

 

[Steve Dion]

There is very little difference in the price of the after market filters and the OEM ones. I would suggest using the OEM Yanmar filters.

I did a lot of searching on filters years ago and there were some very sad stories about using some of these "other" filters.

You will probably get some feed back that they are made by so-and-so, but that does not mean that they used the same standards/materials etc.

 

[RIVERCRUISER]

My preference is to use the OEM Yanmar filter. More expensive than aftermarket. But I only buy two per year for the boat.

I don't think quality brand (Fram, Hastings, etc) is a bad choice. Others may disagree.

 

[Dave602]

According to my Yanmar mechanic who's been in the business for years, Yanmars have a high output pressure on the pump and the Yanmar filters have a built in regulator where as Fram and others do not. At a seminar he showed pictures of engines that had the filter gasket blown through and everything covered in oil. He said over the years he has had more failures from automotive filters than he can count.
Take with a grain of salt but I only use the Yanmar filters

 

[kloudie1]

Lots of previous filter discussion, but Fram 3593A or a NAPA Gold 1568 or the Yanmar 119305-35151. Close in price and I usually pick up whatever is nearest ..

 

[Chris & Lenore]

Fram number, gearbox and coolant - ug!!!

The Fram used by the PO was a PH6606. I have a spare one and will use it for my change to multi-grade oil. It will only be in use for a few hours - then I will switch to the Yanmar 119305-35151.

So here is where it gets interesting. The gearbox calls for SAE 30HD - but the PO used non-detergent. So that will get changed as well.

Then it's the coolant. The red colored "extended life" type is recommended but the PO used the cheaper yellow stuff (which is not recommended everywhere I look).

At least when I'm done I'll know the engine has the proper oil, filter, gearbox oil, coolant, fuel filters, etc.

This is also why I'm pulling the heat exchanger/exhaust manifold so I can check/clean the exchanger and exhaust elbow. This has never been done - nor have the valves ever been adjusted (they seem louder than I would expect - but this is my first diesel, so maybe it's fine).

It does run well. No smoke or soot and only 400 hrs on it, so (hopefully) no real damage was done to it.

Chris

 

[kloudie1]

Chris, the gearbox oil being non-detergent is Ok since there are no combustion by-products in there.. when you change it, change to a modern straight 30 (SN rated) as the transmission guys recommend.. check your filter fit carefully since the 6606 base gasket is about an inch larger in diameter than the Yanmar one. It does not have a bypass valve so if it gets clogged, the media will collapse.. The 3593a, like the Yanmar filter does have a bypass valve in it.

 

[Chris & Lenore]

Chris, the gearbox oil being non-detergent is Ok since there are no combustion by-products in there.. when you change it, change to a modern straight 30 (SN rated) as the transmission guys recommend.. check your filter fit carefully since the 6606 base gasket is about an inch larger in diameter than the Yanmar one. It does not have a bypass valve so if it gets clogged, the media will collapse.. The 3593a, like the Yanmar filter does have a bypass valve in it.

Thanks for the advice. I have a 6606 that came with the boat but will use either a Yanmar or 3593A (depending on what I can find before Friday). The idea of no bypass valve on a filter that would be run at the top end of it's pressure range is not good - especially if my change of oil type frees up a ton of sludge.

Chris

 

[Benny17441]

Ha, I do the to overthink these things...

I guess my main concern was the API designation of the previous owners oil. It's not diesel. His stuff was half the price of the "diesel" oils (I'm sure that's why he used it).
So I might just change what's in the crankcase to a diesel 5W40 and be done with it. I agree with the comments about changing it when the manufacturer recommends. Always done that with my cars - put on tons of mileage and never an engine issue.

Chris

Don't know if it is a typo but I would not go as far as using 5W-40 as the oil might be too thin and lack protection during the start up process. The close to 30 year old Yanmars were not built to such tight tolerances as the automobile engines of today. I have always find that a thicker oil helps bring up oil pressure quicker and enhances compression in those old engines. On the other hand you may not want that thick that the starter cannot turn the engine fast enough. A 15W-40 or 20W-40 might do nicely.