Forum Discussion

johnnieraymcdan's avatar
Mar 17, 2015

8KW Diesel generator

Inside the coach When i push the start button on my 8KW diesel generator I get no clicking as the generator is I guess suppose to be preheating the glow plugs. After 2 to 3 minutes of holding down the start button the generator will finally crank and run perfect. Still haven't herd the clicking I normally hear. Is there a heater that i need to replace or would you have any suggestions

8 Replies

  • Go to the start button right on the generator and compare your results. The remote wiring sometimes needs to be exercised at the connectors.
  • Ivylog's avatar
    Ivylog
    Explorer III
    Doubt it will make any difference but try starting it with the switch on the unit. I would check for 12V at the glow plug before replacing anything.
  • Scott thanks much. i am in South Texas so the temperature should not be the problem. I have a feeling its the heater for the glow plugs which may be a major problem for me to change???
  • johnnieraymcdaniel wrote:
    No it clicked for about 10 to 15 seconds and started immediately


    Iam thinking the clicking is the fuel system coming up to pressure
    as in priming.that's what I was told?

    turns out the Stop/Down button is the prime and the clicking indeed is the glow plugs cycling
    SO if no clicking no preheat very hard starting
    it looks like to me?
    as even in warm weather(hot) my gen start clicks for a set period before it will enter the crank mode and start
  • johnnieraymcdaniel wrote:
    Inside the coach When i push the start button on my 8KW diesel generator I get no clicking as the generator is I guess suppose to be preheating the glow plugs. After 2 to 3 minutes of holding down the start button the generator will finally crank and run perfect. Still haven't herd the clicking I normally hear. Is there a heater that i need to replace or would you have any suggestions


    john,
    The 8K has the same operating characteristics as the 7.5K. First off, the procedure for starting, as you know, is to hold down the start switch for a given amount of time, to allow the glow plugs to heat, prior to cranking. Well, the amount of time that is used for pre-heating those glow plugs, is directly dependent on the outside ambient temp.

    Onan puts out a small chart that describes "pre-heat time" vs outside temps.

    There is a temp sensor that regulates all of it, including shutting down in the event of an over heat condition. But, suffice to say, the colder the outside temps, the longer the time frame is, from pushing the start button, to the time the little engine ECM will allow for the starter to crank varies.

    But, in that chart, it's not "MINUTES" for holding that switch for pre-heat time, it's only seconds. Generally, the chart reads as such:

    > 120 degrees, no pre heat time needed, immediate cranking allowed
    50 degrees, 5 seconds of pre-heat time is needed, prior to crank
    23 degrees, 10 seconds or pre-heat time is needed, prior to crank
    < 4 degrees, 15 seconds of pre-heat time is needed, prior to crank

    Now, if yours is taking as long as you say, and again, it depends on the outside temps, then yes, it sounds as if you may have a problem with either the heater for the glow plugs or, the coolant temp sensor is not allowing the system to work properly. Changing that coolant temp sensor can either be fairly easy or, it can be one serious pain in the a$$. Anyway, hope this info helps some.
    Scott
  • msmith1199 wrote:
    I haven't heard this issue before, but back when you did hear the clicking did it take 2 to 3 minutes for it to start? Mine starts up in probably 5 to 10 seconds and I hear the clicking during that 5 to 10 seconds.



    No before it clicked for about 10-15 seconds and then immediately started
  • I haven't heard this issue before, but back when you did hear the clicking did it take 2 to 3 minutes for it to start? Mine starts up in probably 5 to 10 seconds and I hear the clicking during that 5 to 10 seconds.