Sorry that you are having these issues. That seems unusual to have that many things happen with a Kohler. Lots of people with a Kohler seem okay with them. Generac, on the other hand, seems to have a lot of complaints about service. At least it appears that you have a responsive Kohler dealer.
Kohler 20KW standby Generator issues - low oil pressure
Good day everyone,
I just wanted to share my experience with you all so hopefully it can prevent others from going through this mess.
In January 2018 we decided to purchase a whole home standby generator with automatic transfer switch as we live in an area that does experience frequent outages.
We landed on the Kohler after much debate/research and seeing that the local fire department chose the brand for them, we contacted a local dealer to get it sorted.
Initially, when the team came out to install the unit the generator was placed on the concrete pad and it was fired up for the first run.
It ran for about 30 - 40 seconds before it lifted a ring and completely grenaded the engine. The sound of 3600ish rpms instantly and violently stopping was wild.
Kohler was only willing to replace the engine and not the whole unit however after a lot of pressure from the dealer and myself, a brand new unit was swapped out.
This second unit ran pretty well from 2018-Dec 2021 where it accumulated approx 120hrs of runtime inclusive of the weekly tests plus outages. I began to notice that the interior of the weatherproof housing was coated in a fine mist of oil, this was to the point it was pooling in the bottom of the housing. I contacted the dealer as it was under warranty and had been serviced by them since new. They determined that the intake was full of oil and several oil seals had failed causing it to mist oil absolutely everywhere. This prompted a new engine from Kohler which the dealer installed.
This new engine was installed in March 2022 (supply chain issues I guess), third Kohler engine for us.
On December 15 we experienced a wind storm that knocked power out for 22hrs in which the generator ran flawlessly. I checked the oil after the storm and found not a drop used and the total engine hours were now 40ish hours. The next weekly test of the generator was a surprise for us, the generator threw a low oil pressure light and shut the unit off.
I went out to check it and found the oil filled, looked under the oil cap and noticed a white milky colour to the oil on the cap. I re checked the dipstick and found no water in the oil. The rocker arms all had good clean oil on them and no moisture on them.
I figured it might have been a fluke occurrence so I cleared the code and manually ran the generator. This ran for about 5 min before popping a low oil pressure light and shutting off.
I contacted the dealer who advised that they have had nothing but trouble with Kohlers since they started carrying them in 2018. They did advise that they would come back and replace the oil pressure sensor as they believed it to be faulty (seems odd for less than 50hrs to drop a sensor but maybe). If it didn't work they advised they would push Kohler to replace the whole unit......again.
Again due to issues with parts this has been a good while waiting and we have been forecasted for some bad weather.
Since I had nothing really to lose I tested the oil pressure switch with a multi meter and found with the unit off it would read 2-60 ohms. Given that this is a normally closed switch I cleared the code, rechecked the oil, and manually turned the unit on with the sensor unplugged. While running the oil pressure switch would ohm out to infinity which is a functioning switch. I opened the oil cap and looked in, lots of of good clean oil lubricating the rockers no problem.
I plugged the switch back in and ran the engine for 15min no issue, manually turned it off and rechecked the oil. Again, full of oil and no water.
At this point I'm not sure what is going on nor if the unit will function properly when needed. I hope that this helps someone looking for a standby natural gas air cooled unit to avoid the mess we've had. If money was no option I would pay to swap it for a Generac but I'm stuck with this terrible brand.
Good luck out there and avoid these Kohlers
I just wanted to share my experience with you all so hopefully it can prevent others from going through this mess.
In January 2018 we decided to purchase a whole home standby generator with automatic transfer switch as we live in an area that does experience frequent outages.
We landed on the Kohler after much debate/research and seeing that the local fire department chose the brand for them, we contacted a local dealer to get it sorted.
Initially, when the team came out to install the unit the generator was placed on the concrete pad and it was fired up for the first run.
It ran for about 30 - 40 seconds before it lifted a ring and completely grenaded the engine. The sound of 3600ish rpms instantly and violently stopping was wild.
Kohler was only willing to replace the engine and not the whole unit however after a lot of pressure from the dealer and myself, a brand new unit was swapped out.
This second unit ran pretty well from 2018-Dec 2021 where it accumulated approx 120hrs of runtime inclusive of the weekly tests plus outages. I began to notice that the interior of the weatherproof housing was coated in a fine mist of oil, this was to the point it was pooling in the bottom of the housing. I contacted the dealer as it was under warranty and had been serviced by them since new. They determined that the intake was full of oil and several oil seals had failed causing it to mist oil absolutely everywhere. This prompted a new engine from Kohler which the dealer installed.
This new engine was installed in March 2022 (supply chain issues I guess), third Kohler engine for us.
On December 15 we experienced a wind storm that knocked power out for 22hrs in which the generator ran flawlessly. I checked the oil after the storm and found not a drop used and the total engine hours were now 40ish hours. The next weekly test of the generator was a surprise for us, the generator threw a low oil pressure light and shut the unit off.
I went out to check it and found the oil filled, looked under the oil cap and noticed a white milky colour to the oil on the cap. I re checked the dipstick and found no water in the oil. The rocker arms all had good clean oil on them and no moisture on them.
I figured it might have been a fluke occurrence so I cleared the code and manually ran the generator. This ran for about 5 min before popping a low oil pressure light and shutting off.
I contacted the dealer who advised that they have had nothing but trouble with Kohlers since they started carrying them in 2018. They did advise that they would come back and replace the oil pressure sensor as they believed it to be faulty (seems odd for less than 50hrs to drop a sensor but maybe). If it didn't work they advised they would push Kohler to replace the whole unit......again.
Again due to issues with parts this has been a good while waiting and we have been forecasted for some bad weather.
Since I had nothing really to lose I tested the oil pressure switch with a multi meter and found with the unit off it would read 2-60 ohms. Given that this is a normally closed switch I cleared the code, rechecked the oil, and manually turned the unit on with the sensor unplugged. While running the oil pressure switch would ohm out to infinity which is a functioning switch. I opened the oil cap and looked in, lots of of good clean oil lubricating the rockers no problem.
I plugged the switch back in and ran the engine for 15min no issue, manually turned it off and rechecked the oil. Again, full of oil and no water.
At this point I'm not sure what is going on nor if the unit will function properly when needed. I hope that this helps someone looking for a standby natural gas air cooled unit to avoid the mess we've had. If money was no option I would pay to swap it for a Generac but I'm stuck with this terrible brand.
Good luck out there and avoid these Kohlers
1 - 20 of 50 Posts
First start up grenaded in 40 seconds ? Gotta wonder if they filled it with oil first. But Don't know why you're having issues. I sold high end mowers like Toro and Walker with Kohler engines that performed very well. Considering the way landscape equipment is abused I imagine a Kohler engine would be happy to reside in a generator housing. I also sold Generac standby, stick with the Kohler. As far as the "milky" oil goes is your unit liquid cooled ? If not, have the service tech check the exercise cycle and duration. Short runs can cause condensation buildup in engines. You could also install a mechanical oil pressure gauge to keep the sensor honest.
After my neighbors got Generac whole house units, I looked into it and decided to get a Honda portable instead. We have had a 3 day outage and it performed perfectly. I like that i can take it with me when I sell the house and I was also able to convert it to run on natural gas as well as gasoline with a tri-fuel kit.
If I was to get a whole house unit, it wouldn't be a Kohler or a Generac. Those air cooled screamers are loud and not very reliable. I would get a water cooled Cummins RS25, running at 1800 RPM.
If I was to get a whole house unit, it wouldn't be a Kohler or a Generac. Those air cooled screamers are loud and not very reliable. I would get a water cooled Cummins RS25, running at 1800 RPM.
Oh it was was filled with oil the first time too. I checked with the tech the second it imploded. I have to admit I was laughing because it was just rotten luck.First start up grenaded in 40 seconds ? Gotta wonder if they filled it with oil first. But Don't know why you're having issues. I sold high end mowers like Toro and Walker with Kohler engines that performed very well. Considering the way landscape equipment is abused I imagine a Kohler engine would be happy to reside in a generator housing. I also sold Generac standby, stick with the Kohler. As far as the "milky" oil goes is your unit liquid cooled ? If not, have the service tech check the exercise cycle and duration. Short runs can cause condensation buildup in engines. You could also install a mechanical oil pressure gauge to keep the sensor honest.
This unit along with the others have all been the air cooled units.
I figured the short runs would cause the engine not to get to temp, though it weekly runs are for 30min a shot.
I think the mechanical gauge is the way to go though I like the idea of the low pressure shut off. Given the number of issues I’ve had with these units I would rather it turn off before transforming into a massive boat anchor. Perhaps I’ll put a T fitting in it, connect both sensor and mechanical. Should be mint.
If I could do it again I would go liquid cooled but not sure how the natural gas units are, I’ll research them using better key words like “oil pressure issues” hahaAfter my neighbors got Generac whole house units, I looked into it and decided to get a Honda portable instead. We have had a 3 day outage and it performed perfectly. I like that i can take it with me when I sell the house and I was also able to convert it to run on natural gas as well as gasoline with a tri-fuel kit.
If I was to get a whole house unit, it wouldn't be a Kohler or a Generac. Those air cooled screamers are loud and not very reliable. I would get a water cooled Cummins RS25, running at 1800 RPM.
I’m very lucky to have such a supportive dealer. My out of pocket expenses have been just the initial unit install.Sorry that you are having these issues. That seems unusual to have that many things happen with a Kohler. Lots of people with a Kohler seem okay with them. Generac, on the other hand, seems to have a lot of complaints about service. At least it appears that you have a responsive Kohler dealer.
still would rather the piece of mind vs the worry
I'll say. But in reality that's exactly how a dealer should respond. The more attentive dealer gets much praise in 'word of mouth' advertising. Kudos to them. 👍I’m very lucky to have such a supportive dealer.
I hope the oil sensor cures your latest woe.
It may be too late, but does said dealer offer anything in the way of extended warranty or service?
Dealer does not offer any extend warranty and when I had my third engine put in that was only warrantied by kohler for 90 days. The dealer said it doesn’t matter as they will press for a new unit if any damage was doneI'll say. But in reality that's exactly how a dealer should respond. The more attentive dealer gets much praise in 'word of mouth' advertising. Kudos to them. 👍
I hope the oil sensor cures your latest woe.
It may be too late, but does said dealer offer anything in the way of extended warranty or service?
Are the weekly test runs with or without a load? Running any engine unloaded frequently can cause condensation to build up in oil as witnessed by white slim on fill plug.. If it runs with a significant load, the extra heat will evaporate the water out of the oil.
Are the engines broken-in before you receive them or are you supposed to perform breaking-in?
A break-in with no or little load can cause the rings to not seat good against cyl wall and create excessive crankcase pressure and blow oil out.
The first eng that "lifted a ring" I would assume was due to insufficient compression-ring end-gap. When it heats up, it's too big for the bore and gets stuck breaking piston lands.
Are the engines broken-in before you receive them or are you supposed to perform breaking-in?
A break-in with no or little load can cause the rings to not seat good against cyl wall and create excessive crankcase pressure and blow oil out.
The first eng that "lifted a ring" I would assume was due to insufficient compression-ring end-gap. When it heats up, it's too big for the bore and gets stuck breaking piston lands.
That's good to hear, I agree, he does sound supportive. I hope it continues and things turn out for the better this time around.The dealer said it doesn’t matter as they will press for a new unit if any damage was done
The engines are broken in prior to install as far as I recall.Are the weekly test runs with or without a load? Running any engine unloaded frequently can cause condensation to build up in oil as witnessed by white slim on fill plug.. If it runs with a significant load, the extra heat will evaporate the water out of the oil.
Are the engines broken-in before you receive them or are you supposed to perform breaking-in?
A break-in with no or little load can cause the rings to not seat good against cyl wall and create excessive crankcase pressure and blow oil out.
The first eng that "lifted a ring" I would assume was due to insufficient compression-ring end-gap. When it heats up, it's too big for the bore and gets stuck breaking piston lands.
The weekly tests are unloaded though we do get Some good outages.
I was always curious if the condensation in the oil, however slight it was, was sufficient to get into the sensor and freeze it closed? It was -22C the day of the low pressure fault. Keep in mind I have a carb heater, block heater and battery trickle charger all installed too.
Could have been a fluke occurrence of a perfect storm so to speak
All the other failures, that’s anyone guess I suspect.
The engines are run before going out the door, but I don't think a full break-in is done. In fact, it can take up to about 100 hours for a full break-in. Most of the break-in occurs in the first 10 hours or so.The engines are broken in prior to install as far as I recall.
Here is a link where there is a discussion about Kohler recommending a 50 hour break-in. Take it for what it is worth since it is not your specific gen...
The water condensate in the oil can wreak havoc on a lot of things including sensors, so that might be a possibility.I was always curious if the condensation in the oil, however slight it was, was sufficient to get into the sensor and freeze it closed? It was -22C the day of the low pressure fault
Here is a link to the Kohler FAQ section. It might provide some helpful information.
FAQ | Kohler Power
kohlerpower.com
I Have a 7K Generac that I installed on my folks house in 1993 . Ran flawlessly for @ 20 years .Ran once for 49 hours straight . Always ran Synthetic oil .Oil changes once a year or after a long run . I sold & installed Generacs for almost 30 years after installing his . One day he calls me up maybe 20 years after it was installed & said it didn't do its regular exercise that day , I asked him if the had checked the oil & he said it was real low but it was fine last time he checked it at the beginning of the month . I get there & open it up & I can see some oil dripping & a puddle betweeen the engine & generator . SO I figure the crank seal went out . Figured oil ws low & the oil switch shut it down . We added oil to the right heigth on the dip stick . hit the switch & hear a CLUNK, CLUNK . Turns out the low oil switch failed & the engine tossed a rod . ON my portables & all my friends & put a ohm meter on the switch when we change the oil to make sure it's
working . The unit has been sitting outside of my shop for several years now thinking I'll repower it someday .
animal
ps , those low oil switches are pretty darn expensive these days . Testing the switch is something to think about when you do a oil change .
animal again
working . The unit has been sitting outside of my shop for several years now thinking I'll repower it someday .
animal
ps , those low oil switches are pretty darn expensive these days . Testing the switch is something to think about when you do a oil change .
animal again
UPDATE
I figured I would give an update on this situation since is been a while.
I tested the switch with a multi meter and it ohm'd out properly. I checked the oil and it was full.
I started the engine with the lead removed from the sensor and the oil fill cap open. I was able to see oil coming up to the rockers without any issue. I plugged the lead back in and it ran flawlessly.
I left it as it was and ordered a new switch which has taken a good while to get in. While waiting the generator completed its weekly cycles without issues.
Today after two days of -30C weather, the generator started and shut off quickly throwing the low oil pressure light and warning. The company is coming out on the 8th to service this thing.
I'm leaning towards condensation in the oil which froze the switch closed
I figured I would give an update on this situation since is been a while.
I tested the switch with a multi meter and it ohm'd out properly. I checked the oil and it was full.
I started the engine with the lead removed from the sensor and the oil fill cap open. I was able to see oil coming up to the rockers without any issue. I plugged the lead back in and it ran flawlessly.
I left it as it was and ordered a new switch which has taken a good while to get in. While waiting the generator completed its weekly cycles without issues.
Today after two days of -30C weather, the generator started and shut off quickly throwing the low oil pressure light and warning. The company is coming out on the 8th to service this thing.
I'm leaning towards condensation in the oil which froze the switch closed
Strong possibility of that. When the generator is off, the oil sensor is in its "low oil pressure" state. If there is frozen condensate in the sensor, then the switch may not be able to move to its "good" condition when the gen is started up.I'm leaning towards condensation in the oil which froze the switch closed
I don't know where or what kind of oil sensor you have, but if it is easily assessable and can be unscrewed, perhaps bringing it into the house would let it warm up and dry out. The gen would need to be disabled and the sensor port plugged while the oil sensor is in the house.
Well I think we can all move past the sensor being the issue. I pulled the dipstick took a sample of oil into the house and examined it.Strong possibility of that. When the generator is off, the oil sensor is in its "low oil pressure" state. If there is frozen condensate in the sensor, then the switch may not be able to move to its "good" condition when the gen is started up.
I don't know where or what kind of oil sensor you have, but if it is easily assessable and can be unscrewed, perhaps bringing it into the house would let it warm up and dry out. The gen would need to be disabled and the sensor port plugged while the oil sensor is in the house.
It's got more shimmer in it than a 1980s nightclub. I've contacted the dealer, this will be engine 4.
yea it might be time to make sure you have an old school oil pressure gauge.
so what weight and brand of oil are you using?
and what are the operational temps?
you need to match the oil to the temps outside for a good run unless you have an insulated temp controlled gen shack.
what exact engine is in your gen set?
snap a pix of the tag and of the engine.
and how many run hours?
is this air cooled or water cooled?
so what weight and brand of oil are you using?
and what are the operational temps?
you need to match the oil to the temps outside for a good run unless you have an insulated temp controlled gen shack.
what exact engine is in your gen set?
snap a pix of the tag and of the engine.
and how many run hours?
is this air cooled or water cooled?
I run Mobile one 5w-30 synthetic and its all dealer maintained.yea it might be time to make sure you have an old school oil pressure gauge.
so what weight and brand of oil are you using?
and what are the operational temps?
you need to match the oil to the temps outside for a good run unless you have an insulated temp controlled gen shack.
what engine is in your gen set?
and how many run hours?
As for the engine all I know is that its the standard 20RESCL unit with 61 cu in. 27HP unit.
As of current its just under 40hrs on the clock. Installed new engine March 9 2022, issues started December 24 2022
1 - 20 of 50 Posts
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