Oil & Fuel Kohler 30KW standby generator

[wrede]

My neighbor has a propane fueled 30 KW Kohler with less than 400 running hours. We just had a 6 day power shutdown, and the generator was working fine until it shut down due to loss of oil pressure. It was down over 2 quarts on a 4-5 quart crankcase. The spec. says 5W-30 synthetic oil. The dealer said it needs to be checked every 24 hours, which, of course, requires a shutdown each time. After filling, it ran fine, and after another 36 hours, the oil was down over 1 quart, and the dealer says this is normal. I find that hard to believe. I have a 12 KW Kohler, and the oil level is down maybe a pint, and that is after about 250 hours since the last oil change. My spec. says 10W-30 synthetic. I'd be interested to know of others' experience on this subject.

 

[grsthegreat]

Yeiks...that doesn't sound like any normal engine.

My Old Onan generator has never burnt any oil. I empty and refill at the start of every winter season and its never below the FULL mark.

Does the dealer say what is happening to that oil? is it being burnt.

I personally cant think of having to fill the oil every 24 hours.

I have run very large jobsite generators 150KW size , that were never turned off for 5 days straight. Never added any oil except for routine maint intervals on those either.

 

[Gary Fowler]

You may check this out with another dealer and see if he tells you the same thing. That is not normal oil usage but it may be within what they consider acceptable limits. If it is still under warranty, I would contact the manufacturer directly and express my dissatisfaction with his product and demand a rebuild or replacement engine. Kohler engines sure dont seem to be of the quality that they were 20 years ago.

 

[Mike_VT]

that is not right. gensets are meant to run. I have a 12k lister petter with a 3 cyl diesel and it does not burn a drop of oil.

 

[brokenot]

Kohler engines sure dont seem to be of the quality that they were 20 years ago.

This engine is *probably* a 3.0 GM Vortec, they're common on several manufacturer's standby units of this size, as well as many other types of equipment such as aerial lifts and lot sweepers. I've got the service manual saved on my hard drive if you want a copy. According to the manual, anything less than 1.9L of oil consumption not due to external leaks per 50 hours of run time is considered "normal".

I haven't seen any use that much myself, (and I'm not saying it's *right* either), but if it's what the official GM service manual says, then no warranty considerations will be made unless the consumption increases beyond their "excessive" number.

 

[grsthegreat]

This engine is *probably* a 3.0 GM Vortec, they're common on several manufacturer's standby units of this size, as well as many other types of equipment such as aerial lifts and lot sweepers. I've got the service manual saved on my hard drive if you want a copy. According to the manual, anything less than 1.9L of oil consumption not due to external leaks per 50 hours of run time is considered "normal".

I haven't seen any use that much myself, (and I'm not saying it's *right* either), but if it's what the official GM service manual says, then no warranty considerations will be made unless the consumption increases beyond their "excessive" number.

yeiks.... i am not sure if 2 stroke engines even burn that much oil

 

[MikeD74T]

I try to think of oil consumption as it would be in a vehicle. If you ran a vehicle at 65 mph x 24 hours for 7 days you'd cover almost 11K miles. You'd certainly need an oil change but I wouldn't expect to be 40% low on capacity. I do realize that generators generally run faster than a vehicle at 65 mph. 400 hours would compare to 26k miles, still not where I'd expect that much oil consumption. MikeD74T

 

[5030]

I'll chime in and say my propane fired Guardian (17KW) uses oil as well and has shutdown due to low oil, which is a good thing because it consumes a bit and I don't want a locked up engine.

If we are experiencing an outage, I just shut it down every 24 hours (now) and check the oil, takes maybe 15 seconds. No biggie.

The shutdown took me by surprise first time but I know what the issue is now.

I was using more when I was running 5-30 Amsoil but I switched to 5-40 Rotella Synthetic and the consumption dropped off quite a bit and it's turning some serious RPM, 3600. It's a skewed 2 pole (3600-60hz) armature.

I'm reasonably sure the Lister is tunning a 4 pole head or is coupled to a gearbox. Mine is direct drive.

The OP states he runs his 250 hours between changes. Seems to be a bit extreme. Mine gets changed (oil), filters, air and oil) every year or 100 hours, whichever comes first. My overhead adjusrment is 250 hours.

 

[David_Kb7uns]

My Generac manual says using 5w-30 will increase oil consumption. Using 30W no problems with consumptiom though.

David Kb7uns

 

[5030]

In actuality, all engines consume oil, some more than others but oil consumption is a result of engine design. I'd rather use a bit of oil than face scored bores or valve problems.

 

[JB4310]

Well at least you never have to change the oil, you're putting so much new oil in :confused2:

But if it's within spec, just keep enough oil on hand and thank god for that low oil shut down sensor. 60 horses running 36 hours flat out at 3600 rpm's that's alot of friction to cushion. Cost wise it's not a big deal.

JB

 

[boomer1025]

If it was mine I'd try a 10W30 and if it still sucked oil a 20W50.

 

[5030]

Well at least you never have to change the oil, you're putting so much new oil in :confused2:

But if it's within spec, just keep enough oil on hand and thank god for that low oil shut down sensor. 60 horses running 36 hours flat out at 3600 rpm's that's alot of friction to cushion. Cost wise it's not a big deal.

JB

Cost wise, oil is the cheapest thing you put in an engine.

Not flat out, but a rated RPM and with a varying load. It's essential that the armature turns 3600 (2 pole) or 1800 (4 pole) to maintain 60hz.

Nothing eats insert bearings faster than loss of oil pressure and film thickness.

 

[wrede]

There are no leaks. The oil is being burned, presumably.

 

[5030]

If it was mine I'd try a 10W30 and if it still sucked oil a 20W50.

You have to be cautious with an on demand gneset because if the viscosity of the oil is too high, you run the risk of very premature engine wear, or worse because with a standby, a cold engine will have to assume the load imposed on the generator head with very short notice, typically 15 seconds or less and that can be in some cases, full rated load.

The is basically no fluid warm up and higher viscosity oil can't flow to lubricate vital surfaces.

20-50 could very well spin a bearing or worse.

In larger standby units, there are pre-oilers that have auxillary pumps that immediately bring the oil to maximum pressure and circulation prior to start, as soon as the transfer switches sense urility dropout. Smaller units don't have that luxury.

 

[Gale Hawkins]

The sounds like normal oil usage without a question.

Was he pulling a 300 watt load or was it closer 30K?

Years ago we had an 800 Ford tractor that dad bought new and always ran 10w/30 Chevon oil. It would go the 100 hours between oil changes without requiring the adding of engine oil.

However when he got a AC-72 pull type combine it could burn a quart every full day of combining. Next spring it would break ground for 100 hours and never get more than a quart low.

Hook a full load to the crank shaft where there is NO slippage and most any engine can be forced to use oil.

Small generators are to be shut down and oil checked every 24 hours as noted.

 

[JB4310]

Cost wise, oil is the cheapest thing you put in an engine.

Not flat out, but a rated RPM and with a varying load. It's essential that the armature turns 3600 (2 pole) or 1800 (4 pole) to maintain 60hz.

Nothing eats insert bearings faster than loss of oil pressure and film thickness.

With that much consumption I'm assuming it's 2 pole 3600 rpm. Although most of the 20+ KW generators I've seen the specs for are 4 pole.
An engine consuming that much oil at 1800 rpms does not seem likely ?

JB

 

[JakeBrake]

I don't know that I can really add anything to the discussion, but in my working career I worked with stationary diesel generators from 50KW to 1500KW.

The newer Kohlers from 50KW to about 150KW (I forget the exact break point) were equipped with John Deere diesels made in Mexico. The larger gensets up to 1500KW were equipped with Detroit/MTU engines made in Germany. Kohler was a little slow to convert from 2 stroke diesel engines to 4 stroke diesel engines. The EPA has made 2 stroke diesels obsolete and illegal in some places.

Onan diesel gensets from 50KW to 1500KW were equipped with Cummins diesels. I think most, if not all, were made in the USA. Cummins diesels have always been 4 stroke, as far as I know.

I once attended a seminar at the Onan factory in Minneapolis. They showed us a large ware room full of engines by other manufacturers that could be used in Onan generators if a large customer requested such a thing.

 

[Bird]

Way back in 1973, I bought a little Winnebago motorhome that had a 2.5 KW Onan (single cylinder) generator. When the motorhome was about 4 months old and I changed oil & filter in the engine, the oil in the generator looked dark and thick, so I changed it, too. I used the same 10W-30 oil in the generator as in the motorhome engine. And in the heat of the Texas summer, the generator exhaust was smoky and it was burning oil. I took it to an Onan dealer and left it. When I went to get it, it had been running 24 hours in July heat without using any oil. He said the only problem was that I used the wrong kind of oil; that I needed to stay with a straight 30W or 40W motor oil rated for diesel engines (even though it was a gasoline generator). I never had another problem with it.

 

[JimP]

2 quarts down in 140 hours - yikes!. I am not familiar with the generator, although I thought most of the bigger units were 1800 rpm. Is it a water cooled 1800 rpm unit or an or an air cooled 3600 rpm unit?

We were on generator 5 days last week and 5 days during Irene (same oil fill) and oil level never changed. Onan 7.5 kw generator turned by Kubota 3 cylinder diesel running 1800 rpm. Most of our load was pretty low (lights) unless the well pump or oven was on. I was using Mobil 1 10w30. Just switched to Mobil 1 5w40 but haven't run enough to see if there is any difference in use.