Need help picking correct oil for my 25 year old 19hp twin Generac generator

[Texasmark]

I bought my 11kw, Generac built V twin in 2014. I run it on a direct line to a 500 gallon Propane tank. Once a year I change the filter and oil and use 10w-30 full synthetic. With the Propane fuel, the oil comes out about as clear as it was going in. I have had numerous outages and it runs a checkup run for 15 minutes once a week.

That's my story.

 

[Williy]

IMHO only regular oil 10W30 as being that old the
synthetic oil just might dissolve the gaskets

willy

 

[sixdogs]

I went with 10W30 for the winter and Briggs and Stratton 30W for the summer. All good.

 

[AirOpsMgr]

Great thread with a lot of knowledge being posted; I also have a question regarding the 1st svc, if I may toss in on this.

My 22Kw Generac (LPG fed) was installed about a year ago, I ordered up a filter change kit with the needed filters, plugs, etc, opened it up about 2 months ago and the computer showed it was still under hrs for the 1st svc; Now fast forward to last week and the green svc light on the side is now showing a split orange / green, so I think it's agreeing now that it's ready for the 1st svc.

I live in Middle-GA, no sustained freezing temps during winter and this unit will run mostly in hot temps; So my question for the gents that have posted above mentioning their experience as actual Generac Svc techs: Should I go with a heavier-weight synthetic oil, such as 20W-50 being that most usage is during our hotter summer months, or am I over thinking this?

I don't want to void warranty, but I'm also never going to allow anyone to try to sell me the retardation-level svc plan that the sales weasel tried to get my wife to sign before I heard what they were talking about; He quickly changed his tone when I walked up and politely stated that "We don't pay anyone to do oil / filter changes on this property"

I've already looked over the unit, it's a super simple Svc, about as complicated as doing a quick svc to my Scag; no issues with doing any of it myself, just wanted to check in with the true professionals regarding oil or any other concerns.

Thanks in advance! Best regards,
Greg

 

[sixdogs]

Great thread with a lot of knowledge being posted; I also have a question regarding the 1st svc, if I may toss in on this.

My 22Kw Generac (LPG fed) was installed about a year ago, I ordered up a filter change kit with the needed filters, plugs, etc, opened it up about 2 months ago and the computer showed it was still under hrs for the 1st svc; Now fast forward to last week and the green svc light on the side is now showing a split orange / green, so I think it's agreeing now that it's ready for the 1st svc.

I live in Middle-GA, no sustained freezing temps during winter and this unit will run mostly in hot temps; So my question for the gents that have posted above mentioning their experience as actual Generac Svc techs: Should I go with a heavier-weight synthetic oil, such as 20W-50 being that most usage is during our hotter summer months, or am I over thinking this?

I don't want to void warranty, but I'm also never going to allow anyone to try to sell me the retardation-level svc plan that the sales weasel tried to get my wife to sign before I heard what they were talking about; He quickly changed his tone when I walked up and politely stated that "We don't pay anyone to do oil / filter changes on this property"

I've already looked over the unit, it's a super simple Svc, about as complicated as doing a quick svc to my Scag; no issues with doing any of it myself, just wanted to check in with the true professionals regarding oil or any other concerns.

Thanks in advance! Best regards,
Greg

Let me offer that I run a lot of equipment that is on-road and off road. Not a lot of small equipment but I know a lot of guys with many small engines usually run under duress. In many decades, I have learned to go with the manufacturer's manual. Synthetic is OK if stated and it usually is. I still go with dino oil for the first hours because small engines don't get the mfg quality of a bigger engine and who knows how the cylinder bores are prepped. That's the only wive's tale I follow.

The only timeI have ever used 20W50 synthetic oil was in a farm truck hauling hay up and down the big hills of rural New England. I had a '73 Ford F 600 with a reman engine known for its low oil pressure. I installed a Melling high volume (not high pressure) oil pump since volume is more important than pressure in that engine. In order to get more pressure I went with 15W50 synthetic oil.

The pressure picked up dramatically and all was good. In retrospect of passing years, I've learned not to do that. Many engines require thinner oils and the thicker oils could cause flow and volume problems. I don't know this for sure but have read about and talked with smarter engineer and industry performance car people and come away with that opinion.

Even in my car and truck engines. I used to avoid the required 0W20 and mix some of this and that for a thicker blend. Not any more, unless towing. Then I use the mfg recommendation of a 5W20 or 5W30 for a while. Like you, I also will change my own oil until the last possible moment but I have found a backup guy I can trust for that time.



I believe we overthink oil and that the worst oil of today is better than the best oil of not that long ago. I can't imagine any of us would have an oil issue following mfg specs.

 

[grsthegreat]

Great thread with a lot of knowledge being posted; I also have a question regarding the 1st svc, if I may toss in on this.

My 22Kw Generac (LPG fed) was installed about a year ago, I ordered up a filter change kit with the needed filters, plugs, etc, opened it up about 2 months ago and the computer showed it was still under hrs for the 1st svc; Now fast forward to last week and the green svc light on the side is now showing a split orange / green, so I think it's agreeing now that it's ready for the 1st svc.

I live in Middle-GA, no sustained freezing temps during winter and this unit will run mostly in hot temps; So my question for the gents that have posted above mentioning their experience as actual Generac Svc techs: Should I go with a heavier-weight synthetic oil, such as 20W-50 being that most usage is during our hotter summer months, or am I over thinking this?

I don't want to void warranty, but I'm also never going to allow anyone to try to sell me the retardation-level svc plan that the sales weasel tried to get my wife to sign before I heard what they were talking about; He quickly changed his tone when I walked up and politely stated that "We don't pay anyone to do oil / filter changes on this property"

I've already looked over the unit, it's a super simple Svc, about as complicated as doing a quick svc to my Scag; no issues with doing any of it myself, just wanted to check in with the true professionals regarding oil or any other concerns.

Thanks in advance! Best regards,
Greg

Theres a chart in the manual that specifies oil weights for different temp ranges. Personally, i only use mobil1 5-w30 full synthetic, but im in a colder climate.

once you get between around 25 hours the22 kw will require a valve adjustment. Make sure you adjust them on the proper top dead center (there are 2) or you can destroy engine.

 

[Robin Veerman]

….
I've already looked over the unit, it's a super simple Svc, about as complicated as doing a quick svc to my Scag; no issues with doing any of it myself, just wanted to check in with the true professionals regarding oil or any other concerns.

Thanks in advance! Best regards,
Greg

For you guys with an automatic standby generator…be sure to DISABLE it before starting your service work. You wouldn’t be the first one to have it suddenly start up while you’re in the middle of draining the oil. That would make a service plan cheap by comparison….

 

[JetDoctor1]

If the zinc content is a concern for you I would consider a diesel rated oil like rotella t6 full syn 5w40. Zinc content is greater than newer G rated gas oils that are formulated for longer catalytic converter life. I use it in all my non emission engines, ATV, zero turn, splitter, and boats.

Zinc Dialkyl DithioPhosphate have been gone in diesel oils also since 2004. As far as killing catalytic converters I run ZDDP in every piece of equipment I own and have never replaced the cats on any of my cars. 01' Durango I bought new 205,000mi, 04' VW Jetta TDI I bought new 420,000mi, 18' F150 I bought new 115,000mi, 23' Audi Q7 I bought new, 08' Harley I bought new and all my equipment. My tractor (Kioti CK2620) and small engines have flat tappet cams so its especially important to run ZDDP in those. Modern oils will wipe the cam lobes and send the metal thru the entire engine.

 

[Williy]

Back in the 80's I used 10w30 in all my small engines and never had
any problems. I would not recommend a synthetic unless the manufacture recommends it as the gaskets may not be compatal with
synthetic oil

willy

 

[90cummins]

When new flat tappet cams & lifters are installed in auto’s & truck engines zink or comparable additives are needed/suggested for the initial break-in and they need to run at 2000 +- rpm for a specified time in minutes before they can be allowed to idle.
The cam/lifter are the only parts that need zink. The higher speeds during break-in are to maintain a hydrodynamic film of oil between these parts until they (break-in).
Most small engines yours included have flat tappet cams however the pressure on the cam/tappet interface is on the light side because the engines design speed is only 3600 rpm which limits the contact pressure.
Your cam/lifters are broken in at 25 hours.
Also because your engine runs at 3600rpm hydrodynamic lubrication is established.
So use a quality synthetic with the proper weight according to the local temperatures.
I use Shell T6 5w40 year round so I don’t need seasonal weight changes.
I have gas & diesel equipment & generators so the T6 keeps it simple.
I’d also like to mention that Shell T6 is used in many high performance motorcycles which are much harder on oil than a Generac engine.

90cummins

 

[90cummins]

Disregard forgot this was already beat to death.
90cummins

 

[big bubba]

OP: have you contacted Generac central on oil question?

 

[stormcom]

Valvoline racing oil is very high zinc. I run a 30 wt. (5w or 15w depending where in the country you are). I have a 26kw Generac.

 

[sixdogs]

OP: have you contacted Generac central on oil question?

Sorry I missed this but no, I have not called Generac. I'll get a standard answer that I of don't deviate and all current oils are back-certified,, etc.

I did't see the need to after I found that old style higher ZDDP oil is now made for "off-road" use. I changed oi, used that and feel I'm either good or good enough. Again, sorry I missed your reply.

 

[NYlumberman]

The mills I maintained ran on big Cat gensets. The last one was a 1000HP 3512. All maintenance was scheduled on fuel consumption, not hours or dates. Makes good sense when you think about it. In 1998 I started using a Honda GX4 water pump to transfer water to…well that is really another story. I rigged a 6 gallon tank from an old portable generator to let it run continuously. The motor runs at 1/4 throttle. A full tank would run it for about 6o hours. I change the oil every four tanks, figure 50 gallons because I usually don’t let it run it of fuel. That is about 200 hours of run time. I use the cheapest 10-30 syn-blend I can buy, usually from Walmart but I have used Amazon basic as well. I put another 70 gallons of fuel through it this year, so far. The motor seems a bit down on compression and has started to use a little oil. Still starts on the first pull. I wrote to Honda to share my experience, but never got a reply. By my cocktail napkin calculation using 600 hours a year I now have in the neighborhood of 15,600 hours on a splash lubricated single cylinder air cooled engine (though since it’s a water pump there may be some additional cooling). My point is that oil levels, and oil changes are what is important. If your piece of mind requires a particular brand of oil, then that is what you should use. I use T6 10-40 in all my diesel engines. Mobil 1 5-30 in my pickup. And the 10-30 syn-blend in my gas powered mowers. So far, so good.

 

[Racer4]

I used Mobil 1 5w30 for my Generac 17kw generator. At one point I bought some Traveler synth. 5w30 from TSC to save a few bucks. Put that in and it ended up burning off half a quart in 100 hours. I could smell it when it was running. Switched back to Mobil 1 and no more burn off or smell. Choose wisely.

 

[grsthegreat]

Valvoline racing oil is very high zinc. I run a 30 wt. (5w or 15w depending where in the country you are). I have a 26kw Generac.

Generac specifically says….no additives in oil. They told me to not use a zinc based breakin oil on new engine.

 

[Flogger]

I run Shell Rotella 15w40 in every aur cooled engine I own. In 35 years I have had 0 issues and the only engine I have had any issues with involved a nephew and running upside down. But that's a whole different story. Diesel engine oil has all the specs you need and will keep it cleaner.

 

[DieselBound]

For those wanting high ZDDP, Motorcraft Heavy Duty oil is the ticket: I use this in my 94 Cummins, 2013 Yanmar 3 cly in my Polaris, my 94 Kubota generator, my 2006 B7800 and my ALH TDI; it specs identically to the previous generation Shell Rotella T6, the CJ-4 spec (now CK spec).

 

[Williy]

I read that Generac only makes RV generators now. And
Briggs & Straton has the others

willy