Author Topic: Possible overheated Onan 7.5 KW  (Read 2300 times)

Tom Chace

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Possible overheated Onan 7.5 KW
« on: October 07, 2017, 06:46:14 PM »
I Everyone,
I swapped the rotor/stator - this was the original reason to tear it down
After finishing that job I reinstalled the gen started and was OK
It shut down with a 3 light (service needed)
tap once to get the 2 flash - low oil
Cleared the code
Started again and no problem
An hour of running and it shut down again

I think I overheated my generator.
It will not start now.
It does kick over and run for 10 seconds then quits.

To date I have:

New fuel filter
New temp sensor and thermostat
Cycled through a few gallons of fuel to the injectors
Changed out the rotor/Stator
Changed coolant
Changed oil



I have an oil sensor coming to replace the old one (might be the ultimate problem)
If no - I can core the radiator or flush - probably core it though

Does anyone have suggestions???

Thank You

Tom Chace

99 Beaver Montrey
7.5 diesel QD Generator


Bryan Beamon

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Re: Possible overheated Onan 7.5 KW
« Reply #1 on: October 07, 2017, 07:43:09 PM »
Tom, new fuel lines or new mother board based upond what we went through with our 10k generator.
C & Bryan Beamon
2006  to present
2007 Contessa 42ft Cat C-9 400hp
1996 to 2006 97 Beaver Patriot Camden

David T. Richelderfer

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Re: Possible overheated Onan 7.5 KW
« Reply #2 on: October 08, 2017, 03:37:04 AM »
New radiator fan belt?  These seem to be a common cause for overheating on generators that are long in the tooth.
2004 Beaver Marquis Sapphire

I had a dream... then I lived it!

Jerry Emert

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Re: Possible overheated Onan 7.5 KW
« Reply #3 on: October 08, 2017, 01:58:14 PM »
My 10K had the same symptom last year.  It started fine, ran for a few seconds and quit.  Onan in Grand Junction found a loose pin connection in the harness going to the control board.  Maybe go over all your connections.
Jerry, Chief USN Retired
2003 Patriot Thunder Lexington 40' 3 Slides
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Tom Chace

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Re: Possible overheated Onan 7.5 KW
« Reply #4 on: October 18, 2017, 07:48:24 PM »
Thank You all

As always, I appreciate the help!

Gen is running again with a knock. I am in the process of running that issue down and then back into the RV.

Happy travels

Tom