Onan Generator in for 3rd time on one year old rv- any advice

[2012newmar]

I know next to nothing about engine or generator operations/repair but I bought a 2012 Newmar baystar and it came with an onan 5500 w generator. This is my first rv so I have learned a lot in a year and Newmar has been very good as well as dealer on many things but I ran into a problem in early summer 2012 and went straight to cummins because there is one near me and figured that is best place. The rotor needed replacement and so bolts were loose they said and a major repair but done at no cost to me under warranty. Unit had less than 200 hours on it at time and properly serviced before that. About 3 months later and about 100 hours later again had problem. This time the brush assembly which cummins said was not related to prior and wear and tear so not warranty and the parts were not expensive like $40 maybe but the diagnosis and install get it to $200 plus. This weekend I am at 300 hours and it again won't stay running. I called Newmar and ask them to get involved and have an onan person in the loop but I feel like I have no idea what to make of it not knowing much about mechanics. Do I let them repair it again ? Do I demand a new onan? Has anyone had a similar problem?

[ga traveler]

Onan is the #1 RV generator manufacturer. The Marquis 5500 is a good unit. It does sound like you are having more than normal problems. Are you in a heavy snow area? Salt on the road can be a problem because the unit is air cooled and has lots of cooling holes where salt can go. washing the generator down after going through salted roads can help. keep leaning on Newmar to help you.

[trampsrv]

how much fuel do you have in the tank.

[2012newmar]

Hmmm, I am using the unit in lots of snowy weather bc we ski out of it. The salt built up is somewhat likely. The gas tank is not below a quarter tank. The only other thing the dealer and onan mentioned in regular service and the previous repair is the amount of dirt in the unit. I am not running it on the beach or in a sand pile and I don't know that I am running it it dirtier than normal places but the dealer said he could not believe how dirty it was and I am wondering if that is related to the problem. The salt being a problem...why is that? It clings the holes that air is sucked in? I use it almost every weekend and almost every time I was hit down even when the water is sometimes just above freezing but do I try and aim water at underside of the generator? I do take a wand and hit the underside but I was never really focussing on generator. Can I get water in anything underneath that would be a problem? Does it matter if vehicle or generator running?

[VanDiemen23]

if the rotor was loose I cannot believe that the brushes on the end of it had not been subjected to damage. And, given the tight clearances, I'd bet the stator is damaged as well.

Sounds like they didn't inspect everything well the first time, made some bad assumptions, and now it's biting them back.

[ga traveler]

Originally Posted by 2012newmar

Hmmm, I am using the unit in lots of snowy weather bc we ski out of it. The salt built up is somewhat likely. The gas tank is not below a quarter tank. The only other thing the dealer and onan mentioned in regular service and the previous repair is the amount of dirt in the unit. I am not running it on the beach or in a sand pile and I don't know that I am running it it dirtier than normal places but the dealer said he could not believe how dirty it was and I am wondering if that is related to the problem. The salt being a problem...why is that? It clings the holes that air is sucked in? I use it almost every weekend and almost every time I was hit down even when the water is sometimes just above freezing but do I try and aim water at underside of the generator? I do take a wand and hit the underside but I was never really focussing on generator. Can I get water in anything underneath that would be a problem? Does it matter if vehicle or generator running?

It sounds like salted roads could be part of the problem. i am sure you know that the road dept uses a mixture of salt and sand on the roads. That sounds like the "dirt" problem. After getting the generator running again, try cleaning the generator after each salted road trip. Do not hit the generator with high pressure water with the wand real close, but clean it thoroughly after each salt road trip. Too many times the motorhome manufacturer installs the generator right behind the wheel well where all the spray from the wheel well goes directly on the generator. It makes you wonder how many designers actually use the motorhomes.

[don rider]

On many units if the fuel for the gen. comes from the same tank as the engine the gen supply line is located so as to not draw fuel if the tank is below 1/4 full.

[Hikerdogs]

Originally Posted by 2012newmar

Hmmm, I am using the unit in lots of snowy weather bc we ski out of it. The salt built up is somewhat likely. The gas tank is not below a quarter tank. The only other thing the dealer and onan mentioned in regular service and the previous repair is the amount of dirt in the unit. I am not running it on the beach or in a sand pile and I don't know that I am running it it dirtier than normal places but the dealer said he could not believe how dirty it was and I am wondering if that is related to the problem. The salt being a problem...why is that? It clings the holes that air is sucked in? I use it almost every weekend and almost every time I was hit down even when the water is sometimes just above freezing but do I try and aim water at underside of the generator? I do take a wand and hit the underside but I was never really focussing on generator. Can I get water in anything underneath that would be a problem? Does it matter if vehicle or generator running?

The salt on the roads is eventually crushed by the passing vehicles into a fine dust. When the generator is running it draws cooling air through a couple screens on the bottom of the generator. The air, snow,and and salt particles are circulated through the system by a fan mounted on the top of the crankshaft.

Some of the salt dust gets deposited on the slip rings and brushes. Salt is hygroscopic in that it attracts moisture. Moisture in the air and from the snow mixes with the salt and starts corroding the copper slip rings. Some salt granuals may also dig into the rings and score them. The corrosion forms a film that insulates the rings from the brushes.

When you crank over the generator to start it some of the salt, water and corrosion rubs off on the brushes further insulating them. Some of the remaining salt particles can get stuck in the brushes and further score the slip rings.

As for need ing a 1/4 tank of fuel to allow the generator to run, that's an approximate number. Depending on the configuration of your tank, or where the pickup tube is placed in your tank it may take as much as 1/3 of a tank fot the generator to run.

[2012newmar]

Thanks for help so far. The generator is at cummins and the initial diagnosis is the bolts are loose again and it appears the brushes are again damaged. I did get Newmar to agree to get me an onan contact and waiting for his call but do I demand they scrap the whole unit and replace?

[honkytonkinn]

At the age that its at Id be demanding a new unit, they may say no, but if you dont ask you dont get.
In 2 years time you may be wishing you had asked for a new one.
3 repairs in 12 months is way way above the norm, so whats next.

Rusty

[jcthorne]

Onan is not likely to approve replacement of a year old gen set as long as it is repairable. Rather than asking for something that you are not likely to get and of limited use to you, I would suggest you ask for an extension to the warranty because of this unit's poor reliabillity in service due to manufacturing defects. Onan may very well do this as a customer service gesture and you will get more benefit from it.

[2012newmar]

I have Oman reviewing the three visit notes now. I am so sick of that genny not working and me not being able to use it on three trips now and this weekend we will head to ski mountain with it removed since I doubt they will have it repaired. I don't know enough about engines but if they repair it again do I have a unit that has more hours on it than the clock because it has been beating on itself? They are saying it is somehow out of alignment . Onan told cummins to stop all work so they could asses records and so just wasting my time. I just can't believe they have not already shipped a new one to cummins and move on. What does it prove to repair once again? I appreciate the suggestion to argue a longer warranty. I would not have thought of that. Any thoughts from a gear head on do I feel good about this thing if they will only repair. Very frustrated, thanks.

[Intothewild]

Go with a Honda or yamaha

[SarahW]

Originally Posted by 2012newmar

I have Oman reviewing the three visit notes now. I am so sick of that genny not working and me not being able to use it on three trips now and this weekend we will head to ski mountain with it removed since I doubt they will have it repaired. I don't know enough about engines but if they repair it again do I have a unit that has more hours on it than the clock because it has been beating on itself? They are saying it is somehow out of alignment . Onan told cummins to stop all work so they could asses records and so just wasting my time. I just can't believe they have not already shipped a new one to cummins and move on. What does it prove to repair once again? I appreciate the suggestion to argue a longer warranty. I would not have thought of that. Any thoughts from a gear head on do I feel good about this thing if they will only repair. Very frustrated, thanks.

Did Newmar agree to get involved with your issue? Sorry you are having difficulty.