How long on average did your Cummins Onan vehicle mounted generator last in years?

[Roadtrek Adventuous RS1]

And, how was it serviced? Once per year?

[SteveWolf]

Cobbling it back together was a regular thing, so "how long did it last" is meaningless if it does not take into account the bailing wire and circuit boards required to keep it chugging along.

My issue seemed to be corrosion from using my unit in winter, in salt. Lots of salt. The commutator was open to the breeze and that breeze brought salt. Every terminal was trashed. Phooey!

Dropping that ... literally ... was the best thing I did on my old Winnie. The Generac was light years ahead.

Steve

[Joe]

My Onan driving me nuts too. Where did you mount new gen. I have a 1995 Xplorer 230. Not enough room to mount anywhere. Would have to trailer it.

[Roadtrek Adventuous RS1]

Originally Posted by Joe

My Onan driving me nuts too. Where did you mount new gen. I have a 1995 Xplorer 230. Not enough room to mount anywhere. Would have to trailer it.

Usual place.... my old generator was there... had to replace it due to lack of use... original owners clearly didn't follow maintenance instructions.

[Roadtrek Adventuous RS1]

Originally Posted by SteveWolf

Cobbling it back together was a regular thing, so "how long did it last" is meaningless if it does not take into account the bailing wire and circuit boards required to keep it chugging along.

My issue seemed to be corrosion from using my unit in winter, in salt. Lots of salt. The commutator was open to the breeze and that breeze brought salt. Every terminal was trashed. Phooey!

Dropping that ... literally ... was the best thing I did on my old Winnie. The Generac was light years ahead.

Steve

Steve, even with repairs.. and maintenance... how many years have had service on the same unit?

[peteco]

Mine is 13 years old on my 2006 Roadtrek 210. I have owned for 8 years. Unit had 30 hours on it when I bought. Has 140 hours now. I run it for 30-70 minutes every month or 2. Occasional runs for 2 hours when used for AC. I have used Lucas fuel treatment for past 5 years. Unit starts on 2nd start attempt after an initial 10 second start attempt. Has always worked fine despite the less frequent maintenance runs that Onan recommends.

[rvsprinterguy]

The propane-powered 2500 Watt Onan in my 2004 LTV Free Spirit is still running strong with 80 hours of use showing on the clock. I run it for short periods under load every few weeks and use it to run the roof AC when it's extra hot.

When we bought the coach from its previous owner several years ago, the generator would hunt and surge after the AC or the water heater cycled off, but through regular use, that problem solved itself.

The only maintenance it's gotten in the time I've owned it is a couple of oil changes.

Fortunately, my home is in the SF Bay Area and I don't have to contend with road salt.

[avanti]

My impression is that there is a big difference in reliability between the gasoline and the propane versions of these units, in favor of the latter. Between the two propane units I have owned in the last 14 years, I have never had an issue, except for the infamous "bug nests in the vent tube" problem on the older one, which had no screen. And, I am very far from anal about following the manufacturer's admonition to "exercise your unit every three days".

[Roadtrek Adventuous RS1]

Originally Posted by avanti

My impression is that there is a big difference in reliability between the gasoline and the propane versions of these units, in favor of the latter. Between the two propane units I have owned in the last 14 years, I have never had an issue, except for the infamous "bug nests in the vent tube" problem on the older one, which had no screen. And, I am very far from anal about following the manufacturer's admonition to "exercise your unit every three days".

I've also heard that LPG doesn't gunk up the fuel system like gasoline engines do and also old stale gasoline?

My unit only had 12 or 13 hours on the generator when I purchased my RV two years ago.... original owners plugged in to shore power a lot.....

In September 2018, I had to get a new rotor and voltage regulator... when it stopped working, I should have followed my instincts and replaced the generator back then... just these two items cost $1150...

So.... when the generator failed about a month ago....it was running fine with the A/C and then just shut down....

Brought it back to the Cummins Onan dealership.. they have spent 24 or 25 hours of diagnostics time ruling out bad compression, engine is fine, they systematically went through everything... cannot find what's wrong.... they are still waiting for the special diagnostics tool?? In the meantime, I'm only paying them for the 1 1/2 hours I agreed to for the diagnosis.... but, this time I'm getting a brand new generator.

Hopefully, it will last for the life of time I keep the RV....it comes with a 3 years warranty. And, it's their newest model... maybe it will be quieter... not holding my breath on that.

At least an overhead cam engine is better designed than the old overhead valve. And has more advanced technology and will shut down if the oil level is low.

Just onward and upward... can't go backwards.

[Bud]

"will shut down if the oil level is low"

B onan's have had that feature for many years.

[Roadtrek Adventuous RS1]

Originally Posted by Bud

"will shut down if the oil level is low"

B onan's have had that feature for many years.

Interestingly, that's not what caused my old generator to shut down....

Still a big MYSTERY? If the Cummins Onan dealership can't figure it out....who can?

[Bud]

"Interestingly, that's not what caused my old generator to shut down.... "

Ok, that is maybe, probably the case since you mentioned that the engine noise could also not be diagnosed. More than a couple of B onan's would not start because of a failed low oil switch. Expensive if the person used an onan dealer, near free if self repaired.

[Roadtrek Adventuous RS1]

Originally Posted by Bud

"Interestingly, that's not what caused my old generator to shut down.... "

Ok, that is maybe, probably the case since you mentioned that the engine noise could also not be diagnosed. More than a couple of B onan's would not start because of a failed low oil switch. Expensive if the person used an onan dealer, near free if self repaired.

Bud, it's not low oil or bad oil switch on my old generator.
Don't you understand that I have said they can't figure it out and have 24 hours of diagnosis time and into the machine?

Yeah, I suppose you could have done any better.... fixing it yourself, really????

[avanti]

Originally Posted by Roadtrek Adventuous RS1

Yeah, I suppose you could have done any better.... fixing it yourself, really????

I would think that almost anyone with basic understanding of small engines could do better. There is nothing magic about these machines.

Air+fuel+spark+compression=combustion.

If it is not running, at least one of these ingredients is missing. It is not hard to figure out which one(s).

Any professional mechanic who can't diagnose a problem with one of these machines isn't a professional at all, no matter how much you trust him or her.

[Bud]

Originally Posted by Roadtrek Adventuous RS1

Bud, it's not low oil or bad oil switch on my old generator.
Don't you understand that I have said they can't figure it out and have 24 hours of diagnosis time and into the machine?

Yeah, I suppose you could have done any better.... fixing it yourself, really????

I'm sorry, I misspoke. And it does not make sense, unless a word is inserted:

"Ok, that is maybe, probably the case since you mentioned that the engine noise could also not be diagnosed."

I left out 'not'. With that word, not inserted in the sentence, the sentence makes sense.

Sorry misspeaking.

Bud

[Roadtrek Adventuous RS1]

Originally Posted by avanti

I would think that almost anyone with basic understanding of small engines could do better. There is nothing magic about these machines.

Air+fuel+spark+compression=combustion.

If it is not running, at least one of these ingredients is missing. It is not hard to figure out which one(s).

Any professional mechanic who can't diagnose a problem with one of these machines isn't a professional at all, no matter how much you trust him or her.

Avanti, with all due respect, you know that I took my rig directly to the Cummins Onan dealership..... you doubt that they're professionals?

How's that? I mean, it's their machine and they are factory trained technicians...

Again, reading comprehension here.... it's not the engine.. they have ruled that out.. and, it's not a fuel problem.
They told me that the ENGINE has compression and it's not the problem.....

I'm starting to think that it's possible that there's something internal inside the engine ..a bad part.... BUT, short of tearing down the entire internal combustion engine... I don't think they will do that!

They have literally taken the entire generator apart, I know, they showed me the device on the work bench....all in pieces.. opened up.

What they did say was.... when they did start it, it sounded like a machine gun or jack hammer.... that's all they know..


I would have probably agreed with your assessment had I brought the machine to just anybody?

In this situation, they are stumped for the moment.... they assured me that they will get back to me when they know.... they've already spent 24 labor hours on it....SO....if you still think that this is an easily solved problem, guess again.
You clearly have no idea what you are saying...

Again, I'm very glad I took it to the dealership..WHY?

Any regular mechanic would have just wanted to charge me all of the time for diagnostics.... and they too would have not found an answer ... just let the taxi meter going...
At least the dealership is only charging me for the standard minimum diagnostics time.....the additional 22 -24 hours is on them..... They are very curious as to what went wrong ... they want to find out for future reference.... it's very curious.

Now, let me tell you that the total amount of labor hours spent to find out what's wrong has exceeded the price of the brand new generator.... how about that?

We certainly don't see eye to eye on vehicle repairs...I'm all about maintenance to a very high level....I try and prevent things from failure.... I've been known to have something serviced ahead of time if I'm taking a long trip or something. I replaced a perfectly working water pump on my Subaru Outback just based on years of service when I had the timing belt done. Or, replaced the tires and shocks for safety reasons....

I don't believe that you can simply go by the "book" or mileage... time is an equally important factor....

I was surprised by the generator failure....it failed twice on us unexpectedly... I had it fixed last September... I thought it was fine...

Before you go just impuning the dealership at Cummins Onan, I'd advise you to have something more substantive to say than anyone could have fixed this..... unless you know magic?

Do you know magic?

They promised me that they will eventually get to the source of the problem...a post mortem.... and let me know.
I just think it's possibly a lemon and don't want to keep fixing a generator that has problems especially with two failures like this.

[booster]

Originally Posted by Roadtrek Adventuous RS1

Avanti, with all due respect, you know that I took my rig directly to the Cummins Onan dealership..... you doubt that they're professionals?

How's that? I mean, it's their machine and they are factory trained technicians...

Again, reading comprehension here.... it's not the engine.. they have ruled that out.. and, it's not a fuel problem.
They told me that the ENGINE has compression and it's not the problem.....

I'm starting to think that it's possible that there's something internal inside the engine ..a bad part.... BUT, short of tearing down the entire internal combustion engine... I don't think they will do that!

They have literally taken the entire generator apart, I know, they showed me the device on the work bench....all in pieces.. opened up.

What they did say was.... when they did start it, it sounded like a machine gun or jack hammer.... that's all they know..


I would have probably agreed with your assessment had I brought the machine to just anybody?

In this situation, they are stumped for the moment.... they assured me that they will get back to me when they know.... they've already spent 24 labor hours on it....SO....if you still think that this is an easily solved problem, guess again.
You clearly have no idea what you are saying...

Again, I'm very glad I took it to the dealership..WHY?

Any regular mechanic would have just wanted to charge me all of the time for diagnostics.... and they too would have not found an answer ... just let the taxi meter going...
At least the dealership is only charging me for the standard minimum diagnostics time.....the additional 22 -24 hours is on them..... They are very curious as to what went wrong ... they want to find out for future reference.... it's very curious.

Now, let me tell you that the total amount of labor hours spent to find out what's wrong has exceeded the price of the brand new generator.... how about that?

We certainly don't see eye to eye on vehicle repairs...I'm all about maintenance to a very high level....I try and prevent things from failure.... I've been known to have something serviced ahead of time if I'm taking a long trip or something. I replaced a perfectly working water pump on my Subaru Outback just based on years of service when I had the timing belt done. Or, replaced the tires and shocks for safety reasons....

I don't believe that you can simply go by the "book" or mileage... time is an equally important factor....

I was surprised by the generator failure....it failed twice on us unexpectedly... I had it fixed last September... I thought it was fine...

Before you go just impuning the dealership at Cummins Onan, I'd advise you to have something more substantive to say than anyone could have fixed this..... unless you know magic?

Do you know magic?

They promised me that they will eventually get to the source of the problem...a post mortem.... and let me know.
I just think it's possibly a lemon and don't want to keep fixing a generator that has problems especially with two failures like this.

There are huge complaints on Onan service on all the forums, for years now. IMO, they are not very good at all, from all I have heard, and that includes several instances where Onan did periodic service and shortly after the engines failed due to wrong valve adjustments.


The noise that is describe sounds very much like what you might get with a valve that is sticking open once it warms up. In 20 hours that engine could have been disassembled and reassembled probably 5 times, so this whole thing just looks like lack of skill to me.

[GeorgeRa]

Originally Posted by Roadtrek Adventuous RS1

..........................

Again, reading comprehension here.... it's not the engine.. they have ruled that out.. .................................

I'm starting to think that it's possible that there's something internal inside the engine ..a bad part.... BUT, short of tearing down the entire internal combustion engine... I don't think they will do that!

They have literally taken the entire generator apart, I know, they showed me the device on the work bench....all in pieces.. opened up.

What they did say was.... when they did start it, it sounded like a machine gun or jack hammer.... that's all they know..

......................................

So, it is not the engine but it sounds like a machine gun, a $4 tool could pinpoint the problem.

The spread of technologies is big these days, Onan with an oil scoop for splash lubrication and Mazda with spark - compression ignition in gasoline engine potentially killing diesel.

[Roadtrek Adventuous RS1]

Originally Posted by GeorgeRa

So, it is not the engine but it sounds like a machine gun, a $4 tool could pinpoint the problem.

The spread of technologies is big these days, Onan with an oil scoop for splash lubrication and Mazda with spark - compression ignition in gasoline engine potentially killing diesel.

Hmm, $4 tool?

I really don't know.... and don't you think that the dealership hasn't exhausted all possibilities so far? If it were that simple they would have solved it by now.

As for the other suggestion that "they did wrong valve adjustments....or that their service is NOT GOOD, I would expect that this would come up in their standard warranty on the work they do? If something were to happen, you could return to their shop and they will stand behind their work.

I personally don't believe that all Cummins Onan dealerships are inefficient, poorly trained and mismanaged... that is ridiculous. I walked in their shop with the service advisor...... you could practically eat off the floor.... the place was extremely clean and well organized.

All of these suggestions are just drivel.

I'm picking up my RV on Monday with a brand new generator and I'll have a 3 years warranty on it... should be fine.

[GeorgeRa]

Originally Posted by Roadtrek Adventuous RS1

Hmm, $4 tool?

...........................

A stethoscope is a common tool for mechanics to pinpoint a problem just like your doctor does. It can pinpoint a bad bearing, a valve, a connecting rod, a piston slap anything which can generate a problematic sound. New wireless electronic stethoscopes can detect wheel bearings or suspension issues from the driver seat.

A single piston generator with fixed RPM is the 20 Century level simplicity device, not being able to diagnose a problem speaks a ton about shop capabilities or more precisely lack of them.

I had the LPG powered Onan generator in my previous RV for 5 years with no problems. It was loud but reliable. The total noise of the AC with the generator was too high for even an evening use.