Hey all,Dry camping on our way to Sarasota and I fired up the genset (Onan 5500 Gas-50 amp) and it ran everything fine for 3 hours. Was running 1 AC and a few lights. We had a couple flickers and then about 30 minutes later the lights and AC quit. The genset remained running. So I shut it off. Went out to check the breakers and oil and the breakers were fine but the oil was at the "add oil" line. Strange since it was full and I've only put 5 hours on it exercising it....but I digress. I filled the generator to right below full and restarted the genny. Nothing. Restarted and let it run a bit and voila everything is restored and running as before. Is there a system that shuts down the genset's loads if there is lower oil? I will be checking this thing every few days for a while. My rig is a 2011. Thanks in advance for your comments and wisdom.

These generators are quite finicky when it comes to oil....Mine shuts down when it gets just a bit low....that's for safety so you don't blow the engine up.I am retired AF also 1979-1992 B52 Crewchief 1979-1982 then F -15 Crew chief/phase dock Chief Eglin AFB 1982-1989/ 1989-1992 Kadena AB Okinawa Hardbroke Chief.

I doubt it would shut off the load, rather than just shut off the engine entirely. An engine running without sufficient oil unloaded is not going to fair much better than one running loaded...probably a little better, but still likely to be damaged before too long if the oil is sufficiently low.Methinks you may have a problem with your transfer switch or possibly a loose connection between the generator and the transfer switch. If that's the case, it's something you ought to get fixed pretty soon, as these are the sorts of problems that can cause things to get hot enough to smoke or burn.

Low oil will trip the motor side of the generator. The electrical generation side can in effect disconnect if there is a problem with output voltage or frequency. The problem you're going to have is the problem appears intermittent and unless the generator's built in testing will store fault codes determining what the problems is will be difficult.

NO, Low oil will only kill the running of the Genset. Will NOT affect the 120 output. Doug

Low oil will shut the generator down. In your case you loss power but the generator remained running so NO it's not a low oil problem.

Could Low Oil in my Generator Cause This? | Good Sam Community

37 Replies

Squealers
Explorer
Mar 25, 2015
OK UPDATE!

On our way back from Florida to home we stopped at the Cummings/Onan Service Center in North Little Rock. They did a complete diagnosis and have eliminated the Generator as the issue. They said it is a coach issue and most probably a transfer switch issue, but they do not work on or diagnose those. I will take it to my local RV shop and have this side of the equation investigated.

Thanks again for all your help!
bigdisplay
Explorer
Mar 17, 2015
I had posted the model and belt number I assumed anyone could figure it out from there

Onan Genuine Factory RV Generator Belt 511-0190-01 5.5 Marquis HGJAB
PastorCharlie
Explorer
Mar 17, 2015
bigdisplay wrote:
PastorCharlie wrote:
GOOGLE KNOIWS

Second link down PDF file.

yes we know it uses a drive belt as I have already posted such information earlier

I provided a link to verify the information, you failed to give a link to the source of your information, only that you binged it.

Links to source validate ones opinions.

I wasn't disagreeing with your opinion only giving a link to validate it. :B
W4RLR
Explorer
Mar 15, 2015
My Onan Marquis 7000 had a drive belt, and it was gasoline powered. I even had to replace the belt once.
bigdisplay
Explorer
Mar 15, 2015
PastorCharlie wrote:
GOOGLE KNOIWS

Second link down PDF file.

yes we know it uses a drive belt as I have already posted such information earlier
PastorCharlie
Explorer
Mar 15, 2015
GOOGLE KNOIWS

Second link down PDF file.
cjd10
Explorer
Mar 15, 2015
Rick Jay wrote:
Hi,

I think low oil, or possibly "thin oil", might be your problem. I have an Onan 7000 gas generator on our motorhome. On several different occasions, usually while travelling down the road, I've had the electricity knock-off with the generator shutting down due to low oil. However, I have also observed, on occasion, the electricity gets interrupted yet the generator keeps running. About 30 seconds later, the transfer switch reconnects and all is fine.

Here is what I have learned.

Always check the generator oil and if it's below the full line, I top it off before heading out on the road. We generally run our generator while rolling down the road, so each day of travel, I'll check the oil.

I always use the thickest oil possible as specified by the owner's manual for the temperature range of operation. And it might be psychological, but I seem to have had better luck (more consistent generator operation) with a single viscosity oil, rather than the multi-viscosity oils. The thinner oils slosh around more and that will trick the sensor into thinking that there is a low oil condition and sometime initiate a shut-down. Sometimes, as I mentioned, the engine sputters enough to disconnect the power, but the engine will keep running.

It's taken me a number of years to develop this routine, but I haven't had a generator shut-down due to the oil in several years.

Good Luck,

~Rick

I have had the same thing happen on my 5500, as you said, when the oil is hot and gets sloshed around from a sudden stop, (usually while in reverse) or going slow over a speed bump the AC will shut off momentarily even the the generator is still running. Like you I have found that keeping the oil level as full as possible and using 30 weight oil I don't have the problem
bigdisplay
Explorer
Mar 15, 2015
dougrainer wrote:
bigdisplay wrote:
JNorton wrote:
I do not own a 5500 Onan nor can I after 3 hours looking online find a service manual or a cutaway. I did find the owners manual. I do not believe there are any belts that drive the generator. My 4000 is a direct drive. No where in the owners manual for the 5500 does it mention drive belts. Just something to think about. If there were drive belts and enough oil caused them to slip they would then continuously slip as "bigdisplay" above has stated.

A onan 5500 has serpentyne drive belt and tentioner

This is a RV 5500 Onan????? Where would you have space for a belt and tensioner??????? What model are you talking about? Doug

I Don't know. you said that onan don't have drive belts(your quote:There are NO belts at all on any Gasoline driven RV Genset. Doug)
and according to ONAN the 5500 has a drive belt that's all I said??
what does this belt fit??
Onan Genuine Factory RV Generator Belt 511-0190-01 5.5 Marquis HGJAB
Now all that being said I thought they were direct drive but when the Op said his belts slipping I BINGED onan5500 drive belt and it seems they used one
bigdisplay
Explorer
Mar 15, 2015
dougrainer wrote:
bigdisplay wrote:
Squealers wrote:
Update 2.

Talked to a tech at Lazy Days on the phone. He stated my model, the 5500 has a known issue with a slow oil leak which drips on the drive belt causing it to lose traction and as a result it does what mine is doing and stops electricity generation.

They can't get me in for repairs so I'll continue to search. Thanks again all, and thanks Ij for the numbers and contacts!

I seriously doubt that will be the cause.
If you had that much oil on the belt that it slipped that bad I don't
think it would be intermittent as you say it is

There are NO belts at all on any Gasoline driven RV Genset. Doug

researching a onan gold 5500 they have a drive belt and tensioner and a rubber mounted pulley they say the pulley fails before the belt ever does
However I don't know if the one the OP is the same but to say no Onan has a drive belt is incorrect as some onan 5500 have a drive belt

Right on the Onan gold warrenty it says All HGJ series carry a lifetime warranty on the 'drive train belt"
dougrainer
Nomad
Mar 15, 2015
bigdisplay wrote:
JNorton wrote:
I do not own a 5500 Onan nor can I after 3 hours looking online find a service manual or a cutaway. I did find the owners manual. I do not believe there are any belts that drive the generator. My 4000 is a direct drive. No where in the owners manual for the 5500 does it mention drive belts. Just something to think about. If there were drive belts and enough oil caused them to slip they would then continuously slip as "bigdisplay" above has stated.

A onan 5500 has serpentyne drive belt and tentioner

This is a RV 5500 Onan????? Where would you have space for a belt and tensioner??????? What model are you talking about? Doug

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Could Low Oil in my Generator Cause This?

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