Onan 5500 Genset Uncommanded Shut Down

AFLOGGIE · 03-23-2023, 11:15 PM

Good evening! My 2015 Thor Windsport 32n is equipped with a Onan 5500 GENSET. It has had all the right care but now it has decided to do shut off totally on its own without any command from me. There is no sign of overheating or other visible issues. We have been using the MH quite a bit and have run many gallons of gas through the tank. We live in central Florida and it has not been sitting in storage. I have put an additive in the tank to help keep the ethanol byproducts from building up in both the coach fuel injectors and the GENSET carb. It has just over 200 original hours on the meter.

Does any one have any suggestions as to why it is acting up? Looking forward to see what suggestions are out there.

Thanks,

AFLOGGIE

Scubawise · 03-23-2023, 11:32 PM

Quote:

Originally Posted by AFLOGGIE

Good evening! My 2015 Thor Windsport 32n is equipped with a Onan 5500 GENSET. It has had all the right care but now it has decided to do shut off totally on its own without any command from me. There is no sign of overheating or other visible issues. We have been using the MH quite a bit and have run many gallons of gas through the tank. We live in central Florida and it has not been sitting in storage. I have put an additive in the tank to help keep the ethanol byproducts from building up in both the coach fuel injectors and the GENSET carb. It has just over 200 original hours on the meter.

Does any one have any suggestions as to why it is acting up? Looking forward to see what suggestions are out there.

Thanks,

AFLOGGIE

Cummins does fixes and gave us a 2 year warranty

The Gritz Carlton · 03-23-2023, 11:45 PM

Oil level? They are pretty sensitive to this.

**EA37TS** · 03-23-2023, 11:50 PM

8 years old and only 200 hours the generator suffers from neglect. More than likely you need to redo the entire fuel system.

AFLOGGIE · 03-23-2023, 11:54 PM

Thanks!

AFLOGGIE · 03-23-2023, 11:55 PM

Is a rebuild a big project or should I let the professionals do it?

AFLOGGIE · 03-23-2023, 11:56 PM

Oil level is better than 3/4 up the dip stick well within the safety zone on the dipstick.

Beau388 · 03-23-2023, 11:57 PM

Quote:

Originally Posted by EA37TS

8 years old and only 200 hours the generator suffers from neglect. More than likely you need to redo the entire fuel system.

dkoldman · 03-23-2023, 11:58 PM

When you call Onan, I don't think they will consider 25 hours / year a lot of usage. Maybe if all you ever did was exercise it?

I would start by trying to get the error code. If you don't have a EC-30 you may need Onan manual or Onan Support to help to see why it is shutting down.

**16ACE27** · 03-24-2023, 12:13 AM

Quote:

Originally Posted by AFLOGGIE

Good evening! My 2015 Thor Windsport 32n is equipped with a Onan 5500 GENSET. It has had all the right care but now it has decided to do shut off totally on its own without any command from me. There is no sign of overheating or other visible issues. We have been using the MH quite a bit and have run many gallons of gas through the tank. We live in central Florida and it has not been sitting in storage. I have put an additive in the tank to help keep the ethanol byproducts from building up in both the coach fuel injectors and the GENSET carb. It has just over 200 original hours on the meter.

Does any one have any suggestions as to why it is acting up? Looking forward to see what suggestions are out there.

Thanks,

AFLOGGIE

Get your generator model number
Get your generator manual online
Review the procedure to extract trouble codes.
Next time it shuts down pull the trouble codes and follow the manual. Much better than guessing.

Lt Keefer · 03-24-2023, 12:53 AM

You need a manual or possibly an actual Cummins mechanic, not a silver bullet from the internet.

Pete'sMH · 03-24-2023, 01:10 AM

Quote:

Originally Posted by EA37TS

8 years old and only 200 hours the generator suffers from neglect. More than likely you need to redo the entire fuel system.

Seems about right though if it’s just getting exercised properly. 2 hrs/month for 8 years.

Pete'sMH · 03-24-2023, 01:15 AM

Before spending money at Onan try basic engine troubleshooting. Disconnect the fuel line and see if the pump is pumping. Check the fuel filter, check or simply replace the spark plug and check the wiring, especially the ground connection etc.

**EA37TS** · 03-24-2023, 01:16 AM

Quote:

Originally Posted by Pete'sMH

Seems about right though if it’s just getting exercised properly. 2 hrs/month for 8 years.

The Onan folks will tell you in their seminars that a high age low hour generator is garbage. A 3 year old gen with 600 hours is in better condition than one 8 years old with 200 hours. Been to multiple seminars all stating the same.

Also, as a note, around 14 and 15 Onan had some serious fuel pump diaphragm problems. I had the problem on a 2014 Sunseeker.

dkoldman · 03-24-2023, 01:52 AM

Quote:

Originally Posted by EA37TS

The Onan folks will tell you in their seminars that a high age low hour generator is garbage. A 3 year old gen with 600 hours is in better condition than one 8 years old with 200 hours. Been to multiple seminars all stating the same.

Also, as a note, around 14 and 15 Onan had some serious fuel pump diaphragm problems. I had the problem on a 2014 Sunseeker.

I am going with what he is saying. I have not been to any of the seminars but I have stayed in a Holiday Inn Express.

When we added the EC-30 I had chance to talk with engineers from Onan. They state that owners of AGS system have a call in Support rate a lot lower than those without. Their theory or point is that if you own a AGS, in most cased the owners use it and when you use it you run the genny more than those without.

I try to get 100 hours a years but it is very hard to do. I run my genny for almost any reason I can think of. I never exercise it technically; because I use it for any excuse I can think of; so no need. I just serviced my genny two weeks ago.

For OP, I have seen error codes on my Onan 5500 and none of them required any service from Onan. Follow the advise you got earlier from The Ace on how to extract your codes. I could do the same thing but my EC-30 tracks and stores the last 10 error codes.

AFLOGGIE · 03-26-2023, 08:56 PM

Thanks to all. Spoke to an Onan Service center here in Ocala, FL. He felt that all signs pointed to a faulty Fuel Pump. Picked one up and installed it. Generate cracked right up and ran for almost 1.0 hours non stop without any sign of trouble. Loaded it up with AC on high, External plug with air compressor filling up and not a single sign of trouble. I'm good with the fix!

Appreciate all inputs!!

NATO Rule: Don't worry about your enemies - it's your allies that will do you in.

Jimbo56 · 03-26-2023, 09:02 PM

Thanks for coming back to tell the forum about the fix

Timothys rover · 03-29-2023, 09:51 PM

IF. - your M H is low on its gas, the gen WILL NOT USE ALL OF YOUR GASOLINE. It will shut down.

Quote:

Originally Posted by AFLOGGIE

Good evening! My 2015 Thor Windsport 32n is equipped with a Onan 5500 GENSET. It has had all the right care but now it has decided to do shut off totally on its own without any command from me. There is no sign of overheating or other visible issues. We have been using the MH quite a bit and have run many gallons of gas through the tank. We live in central Florida and it has not been sitting in storage. I have put an additive in the tank to help keep the ethanol byproducts from building up in both the coach fuel injectors and the GENSET carb. It has just over 200 original hours on the meter.

Does any one have any suggestions as to why it is acting up? Looking forward to see what suggestions are out there.

Thanks,

AFLOGGIE

dkoldman · 03-29-2023, 10:10 PM

Post #16 the OP describe the issue and fix.

faulty Fuel Pump

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