Author Topic: ONAN 11.5 DNAD  (Read 9253 times)

mauicole

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ONAN 11.5 DNAD
« on: July 03, 2012, 07:04:38 AM »
Hi all, I just got this Onan/Cummings genset. It has not been run for at least a year.The previous owner was not mechanically inclined and I suspect never had a proper load on her. I haven't found much useful info on the internet yet. Does anyone know about these? I paid $150 for the whole shebang. 













1972 Lister SR1
DES 8/1 w/iron piston & 6/1 cam
1983 Ford F250 6.9L Diesel

dieselgman

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Re: ONAN 11.5 DNAD
« Reply #1 on: July 03, 2012, 12:12:36 PM »
Lister LPW3, and what a steal!!! We have full parts and information for that machine. Notorious for valve-train issues, hydraulic tappets. Carbon build-up can cause catastrophic damage in these so be careful with it!

Always replace water-pump and thermostat around 6,000 hours. Re-torque cylinder head and make sure your ports are clear and clean.

dieselgman
Ford Powerstroke, Caterpillar 3304, Cummins M11, Too many Listers to count...

mauicole

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Re: ONAN 11.5 DNAD
« Reply #2 on: July 03, 2012, 06:15:34 PM »
That's great Gary. It turns over and belches grey smoke but does not start. (That's why it was cheap) Could that be tappet related? I removed an injector and the tip looked pretty good (the tip is pretty small and there was some carbon, but it didn't look excessive) I guess I would have to remove the head to see if there is excessive carbon build-up.  I hope the catastrophic damage hasn't already happened.  :embarassed: What is the life expectancy of these engines?
1972 Lister SR1
DES 8/1 w/iron piston & 6/1 cam
1983 Ford F250 6.9L Diesel

mauicole

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Re: ONAN 11.5 DNAD
« Reply #3 on: July 03, 2012, 11:34:57 PM »
I re-torqued the head - all bolts were less than a half turn loose. :o Intake ports were clean and the exhaust ports looked good too. Still didn't start. There is a intake air heater that has no wire going to it - I don't see why that would make a difference since it's 70F outside today. Is there a simple way to test the compression on an LPW3?
1972 Lister SR1
DES 8/1 w/iron piston & 6/1 cam
1983 Ford F250 6.9L Diesel

carlb23

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Re: ONAN 11.5 DNAD
« Reply #4 on: July 03, 2012, 11:52:45 PM »
are you sure there isn't air in the fuel line.  Sounds like you may need to bleed the high pressure injector lines.

mauicole

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Re: ONAN 11.5 DNAD
« Reply #5 on: July 04, 2012, 01:04:05 AM »
I bled the bleed screw on the fuel filter and cracked all the high pressure lines at each injector. Fuel is flowing and burning(lots of grey smoke puffing out the exhaust) It fires on it's own several times once I stop the starter while holding the rack open (it has a fuel shut off solenoid). I want it to be something simple but I'm running out of ideas. :-\
1972 Lister SR1
DES 8/1 w/iron piston & 6/1 cam
1983 Ford F250 6.9L Diesel

dieselgman

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Re: ONAN 11.5 DNAD
« Reply #6 on: July 04, 2012, 01:43:24 AM »
Turn over with valve covers off and observe proper valve lift on each and every valve... pay close attention to pushrods, they often are bent on a unit that will not start and run.

dieselgman
Ford Powerstroke, Caterpillar 3304, Cummins M11, Too many Listers to count...

dieselgman

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Re: ONAN 11.5 DNAD
« Reply #7 on: July 04, 2012, 01:46:08 AM »
This is not one of the longer-lived Listers... some may disagree, but our estimate is about 10,000 hours engine life on the average for this one.

dieselgman
Ford Powerstroke, Caterpillar 3304, Cummins M11, Too many Listers to count...

mauicole

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Re: ONAN 11.5 DNAD
« Reply #8 on: July 04, 2012, 02:58:03 AM »
Thanks for the help guys. I had this crazy idea that if I took my wife's hair dryer and blew hot air into the intake it might do something. It started up and billowed huge plumes of white/grey smoke out the exhaust. I let it run until my neighbor scowled at me. ;D (about 5 minutes) It's a good thing my wife wasn't around!
1972 Lister SR1
DES 8/1 w/iron piston & 6/1 cam
1983 Ford F250 6.9L Diesel

Tom

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Re: ONAN 11.5 DNAD
« Reply #9 on: July 05, 2012, 04:13:14 PM »
Sounds like you may need a set of injectors. That is usually what white/grey smoke means.
Tom
2004 Ashwamegh 6/1 #217 - ST5 just over 2k hours.

mauicole

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Re: ONAN 11.5 DNAD (LPW3)
« Reply #10 on: July 05, 2012, 09:19:02 PM »
Thanks for that Tom. I really hope it's not the injectors :-[

I started it with no load. The grey/white smoke was extreme for the first minute and then decreased a bit but did not go away. I found a PDF manual online:
http://www.set-zeise.de/UserFiles/File/LP%20Workshop%20Manual%20part%20I.pdf
The trouble shooting section says:

Light Blue Exhaust Smoke
Generally as a result of light load. Investigate the load management programme. (pretty sure the previous owner had no such programme)
Heavy Blue Exhaust Smoke
Lubricating oil passing the piston rings. Check the crankcase vacuum. Check for wear.
Stuck, worn or broken piston rings. Check for damage, decarbonise, replace the rings.
Worn cylinder bore. Replace the piston and piston rings.
Overfull oil sump. Correct the level.

For some reason the dipstick is really loose and seems to show too much oil. I had to borrow the battery from my truck to start the beast the other day, but my wife has the truck today. I'll give it another go tomorrow after I get the oil level right. I was also thinking of feeding it some propane for 5 minutes after starting to clear out some carbon.

I don't understand why the hairdryer helped it start. It's not cold here.

-Cole
1972 Lister SR1
DES 8/1 w/iron piston & 6/1 cam
1983 Ford F250 6.9L Diesel

dieselgman

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Re: ONAN 11.5 DNAD
« Reply #11 on: July 05, 2012, 10:13:49 PM »
Probably light on compression (or improper fuel atomization), this is why a preheat will help start. Remember, the air must compress and heat to the point of fuel combustion... otherwise it will just crank and crank and never fire up.

The smoke does indicate a fuel problem... you can have your injectors checked and if needed nozzles replaced easily.

dieselgman
Ford Powerstroke, Caterpillar 3304, Cummins M11, Too many Listers to count...

ronmar

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Re: ONAN 11.5 DNAD
« Reply #12 on: July 05, 2012, 11:17:43 PM »
I have always interpreted grey smoke as a fuel starved condition.  Do you have fresh fuel in it?  Moisture in the fuel can also cause grey smoke(less actual fuel in the fuel that is being injected)...  Also check your start/run solenoid and the associated linkage and the wiring to it.  If it is hanging up, that could also cause a fuel starved condition.  What type governor does this rig have?  Electric or mechanical?
PS 6/1 - ST-5.

dieselgman

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Re: ONAN 11.5 DNAD
« Reply #13 on: July 05, 2012, 11:43:37 PM »
Cole,

New Standyne injectors for that model are $69 each and readily available if needed.

If you can get it to run well enough, maybe some strong fuel system cleaner can help. Howe's or SeaFoam are common varieties, or if available to you, some good biodiesel will also clean things up pretty quickly.

dieselgman
Ford Powerstroke, Caterpillar 3304, Cummins M11, Too many Listers to count...

mauicole

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Re: ONAN 11.5 DNAD
« Reply #14 on: July 06, 2012, 07:17:40 PM »
ronmar, There is a water separator on the fuel filter, but I better try some fresh fuel. The exhaust smells really rich, is that how it would be if there was water present? The solenoid looks like it's working properly and it has a mechanical gov.

The previous owner had no service records and claimed about a year ago he spent $2000 in repairs that repaired nothing.

I noticed there are new seals on the push rod tubes. But from what I can see of the head gasket, it looks old. Not sure if reusing and old head gasket on these is a good idea. Could this explain low compression and possibly water in the combustion chamber?

Also, the injectors were very hard to remove, nearly rusted in place.

Gary, I have yet to find anyone on island that can test my injectors. (Ahhh, the price of paradise) I suspect it's been some time since they were last serviced-if ever.

From the Alpha Series manual:

Every 6000 Hours
The previous items and give the engine a major
overhaul, if necessary.

:o
1972 Lister SR1
DES 8/1 w/iron piston & 6/1 cam
1983 Ford F250 6.9L Diesel