Generators and Motors
[Home] - [HELP] - [Forums] - [Library] - [Photo Gallery] - [Groups] - [Classified Ads] - [Subscribe] - [Links] - [Books] - [Sponsors] -

Go Back   SmokStak > SmokStak® Vintage Electrical Equipment > Generators & Electric Motors General Discussion > Onan Generators
Forgot Password? Join Us!

Notices

Onan Generators Restoring, operating and maintaining vintage Onan generators.

Onan Generators

Onan 5500 Generator Error Code 58


this thread has 48 replies and has been viewed 11779 times

Reply
 
Thread Tools Display Modes
  #21  
Old 11-27-2015, 04:20:50 PM
Motorhead's Avatar
Motorhead Motorhead is offline
Subscriber
 
Join Date: May 2007
Location: Central Coast, California
Posts: 3,982
Thanks: 1,898
Thanked 2,762 Times in 1,438 Posts
Default Re: Onan 5500 generator error code 58

I would not see overheating a cat by too lean as the engine would be hunting if it was too lean. The cat can get too hot by excess fuel as you said you might have flooded it. Carburetors and catalytic converters don't "Play Well" together.
If the unit sat for a time, the carb dried out and maybe the float stuck down. so when you primed it, it flooded and excess gasoline went into the cat. Some of the experts might be able to tell you how to "Clear" the codes. I would try to clear the codes by unhooking the battery to the set so it is COMPLETELY de-powered. Leave it for an hour or so and reconnect the battery. See if it clears the codes or better yet, google the web to see if you can find the "UN-Dealer" way to clear the codes. Let us know what the fix is.

Last edited by Motorhead; 11-27-2015 at 09:40:17 PM.
Reply With Quote
Sponsored Links
  #22  
Old 11-27-2015, 04:41:13 PM
sleepingdog sleepingdog is offline
Registered
 
Join Date: Nov 2015
Location: Almonte, Ontario, Canada
Posts: 7
Thanks: 2
Thanked 5 Times in 1 Post
Default Re: Onan 5500 generator error code 58

Yes, meant rich, not lean.
Reply With Quote
  #23  
Old 12-05-2015, 03:29:09 PM
sleepingdog sleepingdog is offline
Registered
 
Join Date: Nov 2015
Location: Almonte, Ontario, Canada
Posts: 7
Thanks: 2
Thanked 5 Times in 1 Post
Default Re: Onan 5500 generator error code 58

I thought I would post an update regarding where I'm at with this problem, and what I've done so far. My apologies for the lengthy post.

Today I confirmed that when the engine is running, the choke does open fully after a few minutes. A few minutes later the engine shut down with the code 58.

I then removed the P1 connector and measured the resistance between the two lines leading to the EGT sensor. I saw reasonable resistance values and they were changing in the right direction as the exhaust system cooled.

I then cut those two wires and soldered in a 4.7k resistor between the pair to "fool" the computer into thinking the temperature was stable at around 350C or so. I also connected my ohm meter leads to the lines running to the EGT sensor so that I could monitor that as the engine ran. I started the engine and it ran ok. I watched the resistance change and shut the engine down once it got to 275 ohms, which according to the table in the manual, would be a temperature of about 650C. This is the temperature at which the computer would throw the code 58.

I got on the ground and looked up at the muffler as soon as I shut it down and it was glowing red hot in one section.

I also noticed that, while the engine sounds like it's running fine when I'm right in front of it, if I listen to the exhaust it almost sounds like it's misfiring a bit. I have a recording of the exhaust sound.

So my conclusion so far is that a) the sensor is probably fine and I do really have an EGT problem, and b) it might be because of one of the cylinders not firing properly.

Not sure what I should try next. Any suggestions?
Reply With Quote
  #24  
Old 12-05-2015, 03:41:26 PM
nothingbutdarts nothingbutdarts is offline
Sponsor
 
Join Date: Apr 2014
Location: Bailey, Colorado, USA
Posts: 2,678
Thanks: 6,107
Thanked 1,319 Times in 852 Posts
Default Re: Onan 5500 generator error code 58

Is the engine timing way off????
Reply With Quote
  #25  
Old 12-05-2015, 04:23:45 PM
len k len k is offline
Registered-III
 
Join Date: Jun 2012
Location: Manchester, New Hampshire
Posts: 16,448
Thanks: 453
Thanked 5,956 Times in 4,337 Posts
Default Re: Onan 5500 generator error code 58

I had a 5hp briggs and starton engine with a red hot muffler and low power as it got hot. Aluminum key in flywheel sheared because flywheel bolt was only 1/2 tight .Timing was very late at ~ 25 degs AFTER TDC. I believe yours has magnetoe spark coil, just like my 5hp.
Reply With Quote
  #26  
Old 12-05-2015, 04:37:51 PM
sleepingdog sleepingdog is offline
Registered
 
Join Date: Nov 2015
Location: Almonte, Ontario, Canada
Posts: 7
Thanks: 2
Thanked 5 Times in 1 Post
Default Re: Onan 5500 generator error code 58

Quote:
Originally Posted by nothingbutdarts View Post
Is the engine timing way off????
The service manual specification for ignition timing says "20 deg BTDC, non-adjustable magneto" so it doesn't sound like that's something I can do anything with.
Reply With Quote
  #27  
Old 12-05-2015, 04:44:42 PM
BigBlockChev's Avatar
BigBlockChev BigBlockChev is offline
Subscriber
 
Join Date: Jan 2007
Location: Coquitlam, BC, Canada
Posts: 2,039
Thanks: 366
Thanked 1,550 Times in 911 Posts
Default Re: Onan 5500 generator error code 58

Have you checked the compression, a leaking exhaust valve can cause the exhaust system to overheat. Basicly like lighting a blowtorch into the exhaust system. Cheers Dan
__________________
It's always something simple.
One test is worth a thousand guesses.
If some is good and more is better then too much is just enough
Reply With Quote
  #28  
Old 12-05-2015, 07:55:23 PM
len k len k is offline
Registered-III
 
Join Date: Jun 2012
Location: Manchester, New Hampshire
Posts: 16,448
Thanks: 453
Thanked 5,956 Times in 4,337 Posts
Default Re: Onan 5500 generator error code 58

Quote:
Originally Posted by sleepingdog View Post
The service manual specification for ignition timing says "20 deg BTDC, non-adjustable magneto" so it doesn't sound like that's something I can do anything with.
If key between flywheel and crankshaft is sheared or missing, then flywheel that has magnetoe magnet can rotate relative to crankshaft and change the timing. If you can get a timing light in there you can check timing. If it doesn't have timing marks you can make your own timing mark at TDC on flywheel. That's how I discovered flywheel moved on my 5hp B&S, it also had a non-adjustable magneto design .
Reply With Quote
The Following User Says Thank You to len k For This Post:
  #29  
Old 12-05-2015, 08:27:47 PM
Motorhead's Avatar
Motorhead Motorhead is offline
Subscriber
 
Join Date: May 2007
Location: Central Coast, California
Posts: 3,982
Thanks: 1,898
Thanked 2,762 Times in 1,438 Posts
Default Re: Onan 5500 generator error code 58

I second what len k is questioning. There has to be timing marks on it and it would be worth checking if nothing else to say that is or not the problem. With no load, the muffler shouldn't be red hot. Loaded??? Maybe. Running that hot, I would strongly suggest checking the valve clearance and do a compression check before and after the valve adjust.
Reply With Quote
The Following User Says Thank You to Motorhead For This Post:
  #30  
Old 12-05-2015, 08:39:17 PM
len k len k is offline
Registered-III
 
Join Date: Jun 2012
Location: Manchester, New Hampshire
Posts: 16,448
Thanks: 453
Thanked 5,956 Times in 4,337 Posts
Default Re: Onan 5500 generator error code 58

Think I'ld check compression first as Motorhead recommends, it's easier , and one stuck valve is more likely than timing. Especially if gen been sitting for few years. Other cylinder can keep it running.

For what it's worth, I did notice on my 5 hp B&S that the key did fall out a couple times as I reinstalled flywheel on the crank shaft. So if previous owner had it apart.....

With ~ 25 deg after TDC my muffler was noticeable glowing red at dusk with moderate load, basically the exhaust valve was opening while fuel mix was still burning. Got a 1 ft long blue flame out the short muffler. Muffler = 3 inch dia x ~ 8inch long.

If you use the timing light I'ld use one then the other spark wire as a trigger. Just to make sure both are firing and not intermittent. Most Onans will run fine and make almost full power on one cylinder. If one cylinder is not firing , that's a lot of fuel being burned in catalytic converter (if it has one), red hot.

Last edited by len k; 12-05-2015 at 09:03:22 PM.
Reply With Quote
The Following User Says Thank You to len k For This Post:
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

F o r u m Jump

Similar Threads Chosen at Random
Thread Thread Starter F o r u m Replies Last Post
Onan Microquiet 4000 Error code 32 Brett021 Onan Generators 16 07-30-2018 09:01:30 PM
Onan 7MDKBL-5871F error code 2 Spiv Onan Generators 3 11-14-2016 04:28:31 AM
Onan 12.5 HD CAB Spec A - Code 12 Error Louie Montana Onan Generators 0 08-16-2016 04:31:45 PM
Onan in RV shows error code 11 Kingfish Onan Generators 5 07-29-2016 11:33:43 AM
Onan 7HGJAE type B, error 3 code 15 sdetweil Onan Generators 0 09-03-2013 06:07:16 PM


Use "Ctrl" mouse wheel to change screen size.
All times are GMT -4. The time now is 02:18:41 AM.

Smokstak and Enginads site search!


All use is subject to our TERMS OF SERVICE
SMOKSTAK® is a Registered Trade Mark - A Community of Antique Engine Enthusiasts
Copyright © 2000 - 2016 by Harry Matthews P.O. Box 5612 - Sarasota, FL 34277