Onan Generator Issue - 5500

[ChrisAndGarren]

Hi all -
So, we are on our 2nd year of camping in our MH, and have had a few issues with the generator the past few weekends. Worked fine when used last year (mostly when driving) running 2 AC's - drove in all types of weather (including high desert in E. Oregon) and never had an issue.

This year, we've been out 4 times, and run the generator at least a bit every time. The past 2, when it has been hotter (80-90+) we've been running it and about 20 minutes in, it shuts off. If you try to restart, it won't stay on more than a few minutes. We checked the error code - 36 (engine shutdown) so that's not particularly helpful.

After some research, the internet directs us to a fuel problem, either the filter, fuel line, fuel pump or some combination. Suggestion by the dealer was made to change the air filter and the fuel filter (since they are 3 weeks out for appointments right now) to see if that solves the problem. We're fairly handy but not engine experts.

Here's the fun part.....I can't seem to determine what the replacement fuel filter part # is......here is a picture of the label.

Here are the questions.....

1. do we need 1 fuel filter or 2? What is the correct part #? Am I in over my head - is it harder than the dealer has indicated?
2. What is the correct part #?
3. Am I in over my head - is it harder than the dealer has indicated?
4. Anyone else have a similar issue, and resolution to share??

Appreciate any insights anyone has - Thank you in advance!!!

Garren

[Broadway Joe]

I don't own a generator, but here is the manual for your Model.

[bmurph44]

You say you talked to your dealer so why not get those numbers from them. I'm going to ask the obvious. Have you checked the oil level?

[ChrisAndGarren]

We did check the oil, first thing. The level is fine. When I talked with the dealer, I didn't have the exact model, so I was hoping someone else had experienced a similar issue and had done a replacement. I can call them in the AM with the info.
The manual we have, but it does not have the fuel parts or any instructions,as I think they expect it to be done at the dealer or device center, and being that it's 3 weeks until our appointment and they said it was pretty straightforward, I was hoping we could try it.
They have to replace the awning lights regardless, so she's going in, but if we fix the gennie it saves us some down time.

[Ford1]

My suggestion is to change the spark plug. I have had two generators that did the same thing and after a plug change the problem was solved in both cases. The first time it cost me over $100.00 to have someone else do it. The last time at cost me $6.00!

[j free]

Go to cummings web site and put in the model # on the tag the 5.5HGJAB-10378K they will be able to show all parts and filters for the unit for you. You can also order the parts from them.

[Harkerr]

Might be a fuel pump vapor lock. Need to check all fuel line connections. Is pump located in the gen enclosure ?

[DickiedooFlagman]

Also check your vehicle. Many have the fuel system plumbed so the generator will not draw fuel if the fuel tank is less than 1/4 full. (So you don't run it down and can't drive the MH.)

[Dijoeboss]

I changed the fuel filter on mine no problem....


2013 Georgetown XL 350
Bunkhouse
2002 F250 4X4 CC
2012 Jeep Liberty

[Donamac]

We have a 2014 Georgetown 328TS with the exact same model Onan gen. It ran fine the first year and half, boondocking several weekends. I had 580 hrs. on it when it stopped while boondocking on Derby Day weekend (May 2). We determined there was a fuel issue. After waiting couple of hours and priming for 40 seconds or more, it would start and run about 1 hr. and shutdown. Manuel said change fuel filter at 500 hrs. so I took it to Cummins dealer in Louisville and had it serviced including new fuel filter and spark plugs. Went on 6-wk western trip and tried it for first time in Iowa and it stopped after 30 min. Called closest Cummins dealer on our route in Sioux Falls, SD and fortunately talked to Dennis, their Onan serviceman. It said it could be fuel pump because he had seen several with this issue. Onan had changed pumps a couple of times in the last few years. Had them order a pump (P.N. A047N929) and it was there and installed the next day, all under warranty - no cost. Only lost 1/2 day on my trip. Can't praise Dennis and Cummins Central Power enough.

[ChrisAndGarren]

Hi!
Had a tooth emergency yesterday (root canal anyone?) so just got back to this. Sounds like I have a few things to follow up on! We had a full to 3/4 tank of fuel, so I don't believe it's the low fuel issue, unless the gas gauge was bad.
Dijoeboss - thank you for the part #, that's what I was hoping for.

I appreciate everyone sharing their experience - sounds like there are multiple reasons but most are associated with the fuel input (pump, line, filter etc)

I'll let everyone know what we discover!
Thanks
Garren

[The Wandering Irishman]

Originally Posted by ChrisAndGarren

Hi!
Had a tooth emergency yesterday (root canal anyone?) so just got back to this. Sounds like I have a few things to follow up on! We had a full to 3/4 tank of fuel, so I don't believe it's the low fuel issue, unless the gas gauge was bad.
Dijoeboss - thank you for the part #, that's what I was hoping for.

I appreciate everyone sharing their experience - sounds like there are multiple reasons but most are associated with the fuel input (pump, line, filter etc)

I'll let everyone know what we discover!
Thanks
Garren

Ugh, sorry to hear about the tooth! Any progress on this? We have the same coach (2014 model) and generator, these items will likely make it into the tool\extra parts kit we carry along.

Tom

[ChrisAndGarren]

Originally Posted by The Wandering Irishman

Ugh, sorry to hear about the tooth! Any progress on this? We have the same coach (2014 model) and generator, these items will likely make it into the tool\extra parts kit we carry along.

Tom

Thanks Tom! Tooth is all better now, I decided changing the fuel filter was more than I wanted to tackle, so I took the suggestion and contacted Cummins NW about the generator. The nice service manager made an appointment for tomorrow, his feeling was fuel pump based upon past experience. Looks like it is probably under warranty. Dropped the MH off tonight (open until midnight!) and they will take a look first thing tomorrow. I will let you know what the final result is. The fuel filter and air filter were both available on Amazon however.

Thanks!
Garren

[ChrisAndGarren]

And - a quick unhelpful update....

Talked with the Cummins service center this morning - they got started on looking at the generator. Had a message about 3pm - They ran it for 6 HOURS with no interuption - used multiple loads (AC on/off) etc and nothing happened.

They were closed for the day once I got the message, so we'll touch base in the AM and see what the next steps are. How SERIOUSLY annoying. Maybe we'll just have to drive it around - both times it happened while we were driving on the freeway.

More info once we get it.....

Garren

[Wa11y757]

I've had 2 at work that would run for a certain amount of time, then shut off. Would not restart unless i primed it again . It would start on either and run for a few seconds though. So I knew it was a fuel issue. Both cases turned out to be the fuel filter seam was allowing the fuel pump to suck air, and eventually the carb ran out of fuel. A long prime time would allow it to run for a while, then shut off. To check it, plug off one end of filter and blow in the other end. U will probably see bubbles coming out of the seam... hope this helps and of the diy'ers.

[Jack Durney]

I had the same problem on mine . I don't remember but I think my error code was 36 also . It was a bad fuel pump it was covered under my warranty . I had to pay for the fuel filter but not the pump . I took it to a Onen dealer near by

[mack1roc]

Question for you. You said it was only happening when both ac were running? In most cases you cannot start the generator with both ac units wanting to turn on otherwise it will shut down the generator speaking from experience. I start the front wait till I hear the ac turning on (not just the fan ) and then start the rear. I am sure this is how the dealership does it and might be why they cannot replicate the problem.

[ChrisAndGarren]

Originally Posted by mack1roc

Question for you. You said it was only happening when both ac were running? In most cases you cannot start the generator with both ac units wanting to turn on otherwise it will shut down the generator speaking from experience. I start the front wait till I hear the ac turning on (not just the fan ) and then start the rear. I am sure this is how the dealership does it and might be why they cannot replicate the problem.

Yes, I would not start with a load, we wait about 5 minutes, then turn on 1 ac, wait another few minutes and turn on the second AC. It would run fine, and then about 25 minutes later, it would shut off. After turning off the AC, we would try to restart and it wouldn't stay on for more than 5 minutes, if it would start at all, even with no AC on. So we aren't starting it with the AC on.

They ran it for another 4 hours on Friday with no shutdowns, so I've asked them to change the oil and also the air, oil and fuel filters prior to our pickup on Monday, hoepfully that will prevent anything else.
The only difference between what the dealer has been trying and our experience is the coach being in motion......let's hope that's not the issue.

The tech I have been talking with believes it's either carburetor or the fuel pump, but since it hasn't failed on them, he can't prove it, and can't justify replacing either. I'm hoping it was a ghost in the machine and our oil change + will fix the issue.
I will keep everyone posted!
Thanks
Garren

[ndb767]

had similar problem took it to a onan dealership and they replaced fuel filter and pump. problem was corrected bit now it cant run both a/c s at the same time without tripping the transfer switch.

[Iggy]

You know that the Onan carburetor has a altitude adjustment.
Take a look at it and depending on your altitude you can adjust.
Just may be you are too lean for your altitude.
Just another suggestion.