Community Forums

nettak · 06-14-2020, 06:39 PM

We have an Onan Quiet Diesel 10000 (10HDKCA) that will run for a while and then shut off. Sometimes it will run for an hour, sometimes only 15 or 20 minutes, and sometimes it will shut down immediately. There doesn't seem to be any pattern. I read where overfilling or too low oil can cause this. We sucked oil out and starting from the add line would gradually add a little oil, restart, add oil, restart, etc. Same issue. It would run for a few minutes. Add oil. I ran for about ½ hour. Add oil, only a few minutes. We are back to almost ¾ full.

When it runs it doesn't surge or seem to pull a load. We've run it with an a/c unit on and without. Still can't figure it out.

The air filter was recently changed. The coolant level is full. The generator has only 1537 hours. I can't imagine it being the fuel filter since it will run for a while. I guess that will be one of the next things to try. Any other suggestions?

foundwaldo · 06-14-2020, 07:07 PM

You need to check the code when it shuts down. You press the stop button 3 times after it shuts down it will blink a number 1 - 3. I think you then press the stop one more time to get the the rest of the code. It will blink a series then do a pause and another series. Example it will blink 3 times then you press the stop and it will blink maybe 3 pause and then blink 6 more times. That means the code is 36.

tommar · 06-14-2020, 07:17 PM

Generally, they shut down for either an oil problem or coolant issue. My genny has no gauges just the shut down. Mine would not stay running once and it was because of coolant level. X2 on checking your trouble codes as the other poster suggested.

nettak · 06-14-2020, 07:26 PM

Oh yeah, forgot to mention....the code is 36. Coolant level is fine. Fuel level is fine. Doesn't seem to be leaking any fuel. Air filter was recently changed. I guess I'll need to find someone that services these things.

foundwaldo · 06-14-2020, 07:33 PM

I believe mine was throwing a code 36 m one turned out to be rotted fuel line. I test by running a line straight to the pump and using a funnel. Good luck let us know what you find.

jestal · 06-14-2020, 07:39 PM

I went through this same routine with our 12.5 Kw Onan in an Entegra.

Long story short it was the fuel pump (the lift pump from the main tank to the engine) stopping due to lack of current from the Onan control board. Replacing the board for $800 fixed it.

Take the access panel off he left side. Remove the one screw accessible from the outside and the pump and filter will pull out the access hole. If you are lucky you might be able to see the positive lead going to the pump thru the access hole without pulling the pump out.

Run an extra wire off the pump positive feed wire and to an light bulb with the appropriate ground so the bulb will light when the pump is running. Tape it to the windshield temporarily and keep an eye on it the next time the generator stalls to see if the pump is loosing voltage. That is how I finally caught it. This can be misleading as the board might still be suppling voltage but will not handle enough current to run the motor. The tell tail light bulb might be slightly lite but the pump is not getting enough current.

I ran an extra wire from the positive pump feed wire to outside the cabinet with an alligator clip and the suitable insulation. The next time it stalled I manually powered the pump with my aux lead directly from the battery and it re-started and ran fine.

Onan supplies the lift pump voltage directly from the control board and lots of cases of that board failing the lift pump supply voltage circuit. I think the pump starts to get weak and pulls too much current and eventually overheats the board causing intermittent loss of power to the lift pump. JMHO.

If you have had the coolant bottle out for the air cleaner you can find the largish electrical connector to the main control board. Check that all contacts are good and no corrosion or looseness. Maybe you will be lucky and find the problem there. it has happened...….

I still keep the extra wire on the pump so I can manually supply current if the board fails again (obviously I do not trust the Onan control board.)

There are Onan manuals on line to download to make this more clear with pictures and diagrams.

Harry B · 06-14-2020, 09:54 PM

There have been a bunch of us (me included) who have had this problem on the 10 and 12kw generators. Code 36 is a catch all where it has no idea what caused it to shut down.

For a bunch of us it turned out to be the connector going to the control board having a bad connection.
The control board is located behind the coolant tank. If you remove the tank you will see it. It has a single connector with multiple wires connected. Reseat that connector and you have good chance that it will remedy your problem.
It did take care of my code 36 for about 2 years and it started again. Reseating the connector no longer woked. It took replacing the control board to fix it this time around.

FBL · 06-27-2020, 08:15 PM

Quote:

Originally Posted by nettak

We have an Onan Quiet Diesel 10000 (10HDKCA) that will run for a while and then shut off. Sometimes it will run for an hour, sometimes only 15 or 20 minutes, and sometimes it will shut down immediately. There doesn't seem to be any pattern. I read where overfilling or too low oil can cause this. We sucked oil out and starting from the add line would gradually add a little oil, restart, add oil, restart, etc. Same issue. It would run for a few minutes. Add oil. I ran for about ½ hour. Add oil, only a few minutes. We are back to almost ¾ full.

When it runs it doesn't surge or seem to pull a load. We've run it with an a/c unit on and without. Still can't figure it out.

The air filter was recently changed. The coolant level is full. The generator has only 1537 hours. I can't imagine it being the fuel filter since it will run for a while. I guess that will be one of the next things to try. Any other suggestions?

My Onan 5500 did this for 18 months after working great for years. New oil filter and oil, then new fuel pump and fuel filter. Tried the oil level thing. SO FRUSTRATING!
I stopped at EEE ( fourth repair shop) on my way north. They are near Victoria Bryant SP in GA. It turns out, they are now a Cummins specialist.
The guy opens the cover, and points to the spring which is to the left of the carburetor. It took him five minutes, and he said $10 charge . Three RV repair shops, lots of unnecessary maintenance, and not one of them saw it. I bought a new hanger for the exhaust just because he charged me so little. The 5500 has been humming beautifully ever since!!

THenne1713 · 06-27-2020, 11:55 PM

If gas, I would say replace electric fuel pump first and check fuel filter, BUT DIESEL typically runs and HAS to shutoff fuel to stop (vs killing IGN w/ gas engine). So I advise FUEL FILTER FIRST, check water separator too, and if still fails, suspect you have some other fuel PUMP/ fuel delivery issue? Break out the SERVICE MANUAL?
Download online, Luck to ya

hypoxia · 06-28-2020, 04:37 AM

jestall & Harry B are spot on. The easy things to check are fuel flow and/or air in the fuel line, electrical connector etc. Many folks bypass the fuel pump +12 VDC wiring and install a pump switch. In my case I couldn't figure a good reliable way to do that with Generator Auto Start and Run so I replaced the $800 board which was the cure.

This is a Diesel Generator for those that chimed in about gasoline.

Corc · 06-28-2020, 07:49 AM

Need to see what your fault code is being displayed. It should likely tell you fuel, oil or coolant.

It is possible this is water temp sensor, it will do something similar as it is going bad. It shuts down after a few minutes if it can’t determine temperature.

Hold the stop button down until light comes on. Then tap three tunes to see the last fault code. If it is three flashes, tap stop once more to get two digit fault code. Code 2 is oil pressure, 1 is temperature. 24 is a bad temp sensor. 36 usually indicates fuel.