Author Topic: 10kw Onan generator "huge oil leak...  (Read 11904 times)

Lyle Johnson

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10kw Onan generator "huge oil leak...
« on: May 24, 2016, 12:20:52 AM »
2000 Beaver Marquis
10kw quiet diesel
1100 hrs.

Recently out camping dry...turned on generator...ran about an hour until I smelled smoke and about same time the generator came to a screeching halt ...😩
She froze up...found out no oil...waited...cooled down and replaced oil and luckeee...started up again but not good....ran for another 15 or twenty minutes and she was starting to do the same...shut it off in time to see massive oil leak under coach...

At home checked oil plug...good...filter good...poured in another four qts. and tried again while looking for a problem...2 minutes ok...then inside panel between lower generator and lower part of engine noticed massive oil coming out from bottom part of engine...shut it off...loose about four qts.
of oil in about five minutes...what the heck!
Any ideas?  Looks to me like I will have to pull it out but thought I would try the forum first...
My experience here has been exceptional ...Lyle

Kathy Pylar

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Re: 10kw Onan generator "huge oil leak...
« Reply #1 on: May 24, 2016, 01:30:56 AM »
We just attended the Hoilday Rambler maintenance seminar in Goshen Indiana. This gentleman did a seminar on the Onan Generators. He gave us his phone number and said call anytime. If he doesn't know he will direct you to someone at Onan that can help. His name is Kent 574-262-4611. He was very knowledgable and works for Cummins Onan.  Hope he can help you.

Edward Buker

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Re: 10kw Onan generator "huge oil leak...
« Reply #2 on: May 24, 2016, 09:28:26 PM »
Lyle,

I do not believe that there is any external oil cooler or oil lines so you are possibly looking at a broken oil pan, or a front or rear seal that would have to be really literally gone, or an oil sensor that is totally shot, perhaps there are bolts that if they vibrated out could leak. The sensor would be on a pressure line so although it is small, if it came out for instance (which I have never heard of) it would have oil pressure driving the leak.

There are a number of lighted fiber optic camera arrangements on a metal flexible gooseneck. I have a Bosch version. You may be able to rent one to visually search around a bit to diagnose this. I would also call a main service center of Cummins/Onan and see what they suspect.

Later Ed

Lawrence Tarnoff

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Re: 10kw Onan generator "huge oil leak...
« Reply #3 on: May 24, 2016, 11:39:46 PM »
Ebay has a lot of inspection cameras for under $20.  They connect via USB to your computer.  Search "borescope" on ebay.

Larry

Lyle Johnson

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Re: 10kw Onan generator "huge oil leak...
« Reply #4 on: May 25, 2016, 05:45:17 PM »
Thank you all for your input on this crazy leak...I am still visually looking for the problem...
I will keep you posted on this adventure... At least I can say the engine seems to work "ok" with some residual smoke...but first the problem...

Thanks,
Lyle

Lyle Johnson

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Re: 10kw Onan generator "huge oil leak...
« Reply #5 on: July 07, 2016, 05:02:08 PM »
Update on my massive oil leak on 10kw...
I removed the generator with the help of my bobcat and placed in the shop.  Removed all of the "can", removed the generator, removed engine and placed on engine stand.  Noticed engine had been rebuilt at some time in the past by previous owners.  Pulled Pistons ...50% of rings were frozen solid.  With tech. help from some friends near by concluded the massive oil leak was due to excessive air pressure into the pan due to low compression up top...also noticed no oil pan gasket.
Rebuilt engine, new rings, saved the Pistons, all new gaskets, new alt., alt. belt, rear seal, gen. checked out good, radiator good, new thermostat, hoses when needed. Placed generator back into the coach.

When I purchased this coach used in Bend six years ago I had a generator shut down problem after approximately 4 minutes...then I could restart and it would run continually ...I could never find the solution ...also the generator cabinet was drenched with oil.

The solution to the oil on the cabinet was the hydraulic ram for the slide had a leaky hose...it was a tight connection, but the hose connector needed to be taken apart, hose cut and then refitted.  Fixed.

Massive oil leak problem fixed with rebuild.

Found three problems possibly related to the "shut down" problem:  radiator reservoir drain had no "hole" to enter or release hot or cold water...replaced plastic "useless" piece with brass fitting.  It works...maybe for the first time since new.
Second, when filling or replacing radiator fluids, the radiator hose has to come out of it's compartment with some help then pushed back into the compartment when done servicing...the problem I found was the hose was way to long causing a crimp in the hose which in turn resulted in making the radiator cap useless entirely for it's intended purpose.  I cut nearly 4 inches of tube off resulting in "no" crimp.  Problem solved.
Third...fan belt was not only very loose but almost shot.

I don't know if any or all of this stuff is of help to anyone but I know I have gained a lot of insight from this forum and I appreciate all the help.

Next...pulling the "belly" air.

Lyle
The following users thanked this post: Joel Ashley

Edward Buker

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Re: 10kw Onan generator "huge oil leak...
« Reply #6 on: July 07, 2016, 11:37:10 PM »
Lyle,

Excellent summary and you did yourself proud with all that work. You will know that generator like the back of your hand after this rebuild.

This link has some info in it about belt problems from myself and other sources. A quick summary is the narrow belt configuration has some durability issues, the narrow belt with the alternator option is more problematic. The Bando belts sold by Cummins are poor quality and I upgrading to a Napa 7320XL which yields a longer life if that is one that fits your configuration. If you have the alternator option, which I think came on later gensets then yours, it is not necessary to leave it functional with another charging option available. I had a Cummins lead generator tech tell me to pull the wires on the alternator and tape and tie wrap them off if you had an alternate battery charging source. The load on the belt from the alternator, fan, and water pump causes early belt failure vs those gensets with the wider belt or an idler pulley. More info in this link.

http://beaveramb.org/forum/index.php?topic=4511.0

Later Ed


Lee Welbanks

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Re: 10kw Onan generator "huge oil leak...
« Reply #7 on: July 08, 2016, 12:04:50 AM »
Lyle,

Great job with the Onan and finding the hydraulic leak.

Lyle Johnson

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Re: 10kw Onan generator "huge oil leak...
« Reply #8 on: July 08, 2016, 02:41:02 AM »
Ed & Lee,

Thanks for the kuddos...
The belt I purchased because Napa was out is a "optibelt RBK 36320" . I hope I can get more than 50 hrs. out of it...don't know it it is good or not but bought two and gave one to the local Onan guy to use in another 10kw sitting on his floor with belt problems...that particular 10kw had only 245 hrs. on it.  Interesting.

As stated in my last post, I am now researching the air condition unit to take it out.  I purchased the coach with a new rebuilt unit installed but it never did work so here I go...

Thanks again,
Lyle

Doug Allman

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Re: 10kw Onan generator "huge oil leak...
« Reply #9 on: July 08, 2016, 01:00:07 PM »
Lyle, when you say belly air are you talking about the Cab air or the rooftop air? I am in process of recharging my Cab air on my 2004 Marquis and it has been fun so far. I have ordered the accumulator 3 times and hopefully they send me the correct one this time.

Lyle Johnson

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Re: 10kw Onan generator "huge oil leak...
« Reply #10 on: July 08, 2016, 04:50:11 PM »
I guess I should have said "basement" air...although my "dash air is not working either...seems to be a major problem with most coaches from what I read.   I have been reading whatever I can about all of this before I get started.   Although we prefer not to use so much air conditioning, it is handy in some areas of travel; not to mention the fact that if it is included in a vehicle ...then it should "work" to some extent.  Just my opinion.

Doug Allman

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Re: 10kw Onan generator "huge oil leak...
« Reply #11 on: July 08, 2016, 05:56:15 PM »
I think Gerald is your best on the basement air. I do not have that feature.

Gerald Farris

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Re: 10kw Onan generator "huge oil leak...
« Reply #12 on: July 08, 2016, 06:45:53 PM »
Lyle,
I have some fairly extensive experiences with the basement air on a 2000 Marquis, and if I can be of any help to you in diagnostics or repair, please email or call, and I will try to help in any way that I can. The diagnostic, removal, and replacement instructions are to involved to post on the forum because of the limited interest here.

There is a good chance that your problem could be a circuit board issue, and that is a 10 minute repair plus the $85 charge to rebuild the circuit board (https://www.flightsystems.com/rv-generator-controls-repairs/scs-victory-climate-control-repair-service.html).

Gerald