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SouthernLoCo's avatar
SouthernLoCo
Explorer
Apr 04, 2015

Onan QG 5500 EVAP fault code 58

I just purchased a Jayco Seismic TH from camping world in Dec. of 2014. The trailers has a factory installed Onan 5500 (model # 5.5HGJAB-6755K. When trying to start it for a maintenance run, I somehow flooded it. Proabably over primed it. I was finally able to get the thing started and it sputtered and blew black gunk out of the tail pipe.

Once it was cleared itself, it began running just fine. Maintains constant throttle, no loud noises....nothing. Howeever, it will run for about 10 to 15 minutes on the initial start-up, then stops itself. Throws error code of 58 which is high exhaust gas temp. Looked in service manual, and it says to take to dealer.

Not wanting to down my trailer at the dealership for a month, I called Camping World for tech support. They were nice and courteous, but could not answer my question. Said he would have to call Cummins. I tried calling Cummins too, but was told they will absolutely not give tech support over the phone. Go figure! A customer wants to troubleshoot before bringing item in for warranty issue, and no help! No customer appreciation now days!!

I've looked at other forums and finding no help. Seen everything from bad magneto, to varnishing of carb, etc. My unit runs great before the exhaust heating up and throwing code 58.....every time. Under load and not under load. Engine is clean as a whistle and brand new (2015 trailer). Has 22 hours on it. Gas is clean.

I've taken the spark arrestor out and ran the unit as per service requirements. It still cuts off. Did not blow much of anything out of the spark arrestor hole.

I'm at a loss. Any idea would be appreciated.

Thank you
  • First of all, sorry about the typos on the OP. Took out the exhaust gas sensor and the probe seemed clean. Put back in, started, and put load on generator. Made it 10 minutes, shut down with code 58. Just keeping y'all advised. Thanks
    • Tennist's avatar
      Tennist
      Explorer

      Did you ever figure out the issue that was causing this?  My geny is doing the same thing.  Runs great but shuts off after about 10min with code 58.  Doesn’t surge starts right up.  I can’t figure out the issue.

      • way2roll's avatar
        way2roll
        Navigator II

        You are responding to a post that's almost 10 years old. You may have better luck asking your question in a new post. 

  • I'm thinking the fuel pump is your culprit. Install a new one, should fix issue. 

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