Onan Generator Won't Turn Over

[Dwight Wilson]

Just a thought but that blast of white smoke typically indicates unburned fuel in a cold start, Has anyone checked to see if the glow plug is functioning?
Dwight

[Brent Hohlweg]

So I'm going to throw this out there, as I dismissed the idea after the technician said he had never seen a glo plug fail...(see pics).

Plug #1 area is covered in oil. Could there be oil getting all over the glo plug somehow and gumming it up so that essentially all I'm getting is two good plugs to work? Maybe the plug just needs to be replaced.

Also here is a video of the gen failing to fully starting and the white smoke. Just click to download (link valid for 30days): https://www.dropbox.com/s/883c504tqrhd8v8/Video%2012-14-2013%2C%2011%2059%2030%20AM.mov

Cheers Brent

[Steve Huber Co-Admin]

Brent,
White smoke is usually an indication of unburned fuel. Check the air filter and housing to be sure both are clean. Also, try starting the geni with the load disconnected (should be a circuit breaker on the geni). If it starts, let it run for 10-15 minutes to get rid of the unburned fuel in the exhaust system. The apply the load. If it continues to run, let it run for at least 15 minutes. As other have noted above, if it cranks with 12+ volts you don't have a battery problem.
Steve

[Edward Buker]

Brent,

To get the terminology right, when you say it will not turn over, to us that means that the starter will not turn the crankshaft when the starter is engaged. Your case is that the starter engages and the genset turns over but it will not start. If it cranks over at good speed then low voltage at the starter and poor connections are not your problem. So as a symptom what you have is the genset cranks but will not start. So the first thing to have them check is that the system that powers on the glowplugs is working, the duration of glow plug on time is correct, and that the resistance of each glow plug is as it should be. If that is correct then the next system is fuel supply.

Later Ed

[Brent Hohlweg]

Ed, Gerald, Steve, Dwight, Dave and everyone who has posted on page 1...major thanks for all the extra info!

I started this process knowing nothing about my generator. As of now with this forum, tons of YouTube videos, Googling, and going to the Cummins shop I'll be able to do all my regular maintenance myself :-)

I'm returning to Cummins again on Monday and will post here the update.

Brent

[Brent Hohlweg]

UPDATE:

At this point after 2 days of testing and stumping the technicians...Cummins has pulled the generator and it looks like it might be an electronic fuel pump. I'll post the final diagnosis. Thanks again everyone.

Cheers Brent

[Brent Hohlweg]

UPDATE (SAGA Cont):

These we're the items repaired - generator worked for 2 days and has now stopped working again and I'm reading Code 45 (four flashes - five flashes) coming up. We have no gen power on Christmas Day so the better half is less than impress :-(

Here is what Cummins diagnosed so far:

1. A sticking 'speed actuator' and replaced.
2. One defective glo plug and we replaced all three.
3. A 1-2mm crack in a hose (see above pics) that lead to area by glo plug #1.

We have left El Paso now, so we will have to hit another Cummins on the 27th in Lake Charles, LA.

I'll continue to keep posting in hopes that is helps others in the future.

PS: For all others having their generators pulled out... I just read another BAC post on generators and now see that Cummins should have replaced due to age "Replacing the temperature sender unit, belt, and thermostat..." http://forum.bacrallies.com/m-1387907037/s-new/#num2 (hope that also helps others).

Merry Christmas everyone,

Cheers Brent

[Edward Buker]

Brent,

The thermostats rarely fail. The temp sensor can fail but not very often so that one is personal choice. If you are at a point in repairs where the belt is accessible and it is over 3 year old or shows any signs of wear or drying out then by all means change that out and save a future headache. This is my own opinion created from trouble shooting an overheat problem with my own genset. I had access to how many of each of these parts were sold each year from a Cummins/Onan parts manager (including water pumps which were almost never). He could do a national look from his computer terminal and from that you could see the real culprits by the number of part sales....

Later Ed

[David T. Richelderfer]

Just a note:  While I was in the Challenger Automotive shop in Lake Havasu City late on Friday, December 20, 2013, discussing my Onan generator problem, Bill McVicker received another call from another motorhome/Onan owner with exactly the same error condition, e.g., temperature sensor fault.  The other owner was told the identical story as I had just received - come in Monday and we'll order the parts.  When the parts arrive, then we'll make a firm appointment to bring in the coach for a one-day in-and-out repair.

I remember Bill pointing out that the temperature sensor's and thermostat's longevity depends in large part on how often the engine's coolant is changed.  I have no idea when or if at all the thermostat and belt had been changed since the generator was manufactured.  My generator's S/N starts with J02....  That's a 2002 manufacture date - over ten years old.  So I elected to get 'er all done.

Except for the expense, this has been yet another great learning experience.  And $500 to $600 is relatively cheap after hearing about tow-jobs, alternator problems, leveling issues.  I just can't wait to change my eight tires... lots of zeros in that bill.

[Robert Mathis]

David, I had to replace all 8 of my tires this spring, go with the Monaco International program if you can, it saved us a ton of money, like $200/tire. I'm like you, if my genset needed to have serious parts replaced, I'd go ahead and replace the belt, thermostat and coolant. I figure it's cheap insurance

[Brent Hohlweg]

FINAL REPAIR UPDATE:

So we arrived at Cummins Mid South, New Orleans. The repair was covered under warranty for the work of El Paso Cummins shop - so no payment. They had a Onan generator specialist with over 15 years experience (Ronnie O.). Took him 30 minutes to diagnosis and work in reverse to find the problem of the Code 45 Speed Sense fault:

1. A loose and broken wire on the relay. Replaced and generator has been working great since.

Thanks again everyone. Hope this post and thread helps others in the future.

Cheers Brent