5500 Onan quits after 1-2 hrs use, then starts back up

Same here. I hope, and will find out definitely this weekend that this was the cure.

I'll post the results after camping.

Interesting.
I have always poured 2 quarts in per the manual and no issues.
Did you pour more than 2 quarts in at the last change?
Onan OEM filter?

Hey guys. After researching everything I could on line, I came across a guy who had discovered that his oil level in the engine was affecting the generator. He had filled it to the max level, and suddenly started having "shut off" issues like mine.

I recently changed the oil in the generator too.

He removed enough oil to set the level at 1/4 way over the need oil line .. He ran the generator and it stopped dying out..

I tried this and sure enough my generator has not died since..

Don't ask me what, or how but others on his youtube post had the same results...

Found a abbreviated Onan 5500 manual on line, it has the trouble codes and how to find them.
Starts on page 35 and goes to page 38.

https://www.manualslib.com/manual/882561/Cummins-Hgjbb.html?page=35#manual

joebedford wrote:

allcool wrote:
First place to start troubleshooting your 5500 is to get the trouble code from the controller.

He already said he got a 34. What's your diagnosis?

roller183 wrote:


The best code I could pull from it was a "34" ..Can't find a fault code list to save my life. Looked at Cummins page, nothing. Did searches no luck..

TIA. Checked the search engine here but probably used the wrong wording.

Ya, saw that but it left me confused, not sure what "best code I could pull" actually means. As there is no code 34 or best code. Code is either stored on the controller or its not.

I have the Onan shop manual, but its over 7 megs and I don't have a hosting site. If anyone wants a copy, let me know what address to load it to. not sure if email will take a 7meg file..?

Ok Thanks. Going to check it out this weekend.

Here's a cheat sheet I have for common faults:

Onan common fault Codes Cheat Sheet


• Two blinks indicates a low oil pressure fault.

• Three blinks indicates a service fault.
Press Stop once to cause the two-digit, second level fault code to blink.
(Pressing Stop again will stop the blinking.)
The two-digit code consists of 1, 2, 3, 4 or 5 blinks, a brief pause, and then 1 to 9 blinks.
The first set of blinks represents the tens digit
and the second set of blinks the units digit of the fault code number.
For example, Fault Code No. 36 appears as:
blink-blink-blink—pause—blink-blink-blink-blink-blink-blink— long pause—repeat

• Four blinks indicates that cranking
exceeded 30 seconds without the engine
starting.

Restoring Fault Code Blinking – The fault code stops blinking after five minutes
(15 minutes, Series HGJAA).
Press Stop three times within five seconds to restore blinking.
Note that the last fault logged will blink, even after the condition that
caused the shutdown has been corrected.


TABLE 5. TROUBLESHOOTING

LOW OIL PRESSURE FAULT—CODE NO. 2
(First-level fault code—Low oil pressure cutoff switch did not open)

SERVICE CHECK FAULT—CODE NO. 3
(First-level fault code—Indicates fault with second-level fault code)
Corrective Action: Check the second-level fault code by pressing STOP once.
The second-level fault code will have two-digits.
The faults are listed in numerical order in this table.

OVERCRANK FAULT—CODE NO. 4
(First-level fault code—Cranking exceeded 30 seconds without engine starting)

LOW OIL PRESSURE CUTOFF SWITCH FAULT—CODE NO. 23
(Controller sensed switch still open during start—not a running fault)

ENGINE STOPPED FAULT—CODE NO. 36
(Engine stopped without command by controller)

OVERPRIME FAULT—CODE NO. 57
(Prime mode exceeded 3 minutes)

allcool wrote:
First place to start troubleshooting your 5500 is to get the trouble code from the controller.

He already said he got a 34. What's your diagnosis?

Agreed with allcool.

Jfyi,to correct some misconceptions in this thread on Onan 5500.

1)Onan 5500 is Not a inverter, its a generator only
2)Onan 5500 is an air cooled engine,
absolutely no over heat protection or no overheat safety shut down at all

First place to start troubleshooting your 5500 is to get the trouble code from the controller.
Use the manual to find out how, its easy and well explained in owners manual.

Once you get the code # come back and tell us so we can help.
Everything else is a guess at best. If you don't want to chase your tail around, trouble code is the best way to start troubleshooting the 5500.

jmo