Onan 7.5 diesel generator has a mind of it's own.

[herman pahls]

Seven months ago I purchased a low milage 2005 Winnebago 36' Journey.
It came with a Onan 7.5 diesel generator.
This is my first Diesel powered MH and noticed the diesel generator takes 30-45 seconds longer than a gas generator on the first start of the day, probably due to glow plugs.
It starts every time but the issue is that it may run for several minutes or sometimes an hour and then shuts itself off.
It always  re starts immediately and it does not seem to care if it has a load or if the outside temperature is cold or hot.
The fluid levels are in the normal range.
I live 3 hours from the nearest Onan service center and would like to see if this forum has any ideas before I make an appointment.
Thanks
Herman

 

[markbarendt]

It could be something as simple as a loose wire. Kind of poke around in there and see if you can find anything that's loose or looks like it's worn through because of laying on the  Sharp edge or  something similar.

There's  probably also sensors or overtemperature  and other faults.

Sometimes it's also easy to Google the problem you're having. With a little bit elect somebody else has had the same problem and put up an answer.  I try to use as few words as possible when I'm doing this type of search.

 

[Gary RV_Wizard]

The Onan gives a trouble code if its shuts down, so that's the first thing to check. Obtaining the code and interpreting it are covered in the owner manual.

Have the genset fuel & air filters been changed?  Fuel & air are primary things to check on any engine, but especially on a diesel, where there is no ignition system to fail.

While glow plugs do have to heat up, it should not take 35+ seconds to start the Onan except in very cold weather. More like 5-10 seconds.

 

[oldwasichu]

Spark arrestor plug may be full of soot. That will cause a premature shutdown if it is packed and hasn't been cleaned out in some time. Easy DIY procedure as long you have a long socket extension because it's way up in there.

 

[herman pahls]

Thanks for the replys.
I will check out the owners manual.
I had no idea they set off codes.
I will also check the filters, spark arrestor and possible chafed loose wires.
Thanks
Herman