Onan 7.5Kw Quiet Diesel Generator Turns Off

[barmcd]

It was running fine. I ran it four hours in March and April with the AC running to give it some exercise. Then at the end of April, I noticed the number of hours on the meter was higher than it should be and Katherine told me she'd heard it running in the middle of the day. I turned the auto-start feature off on the inverter and the generator stopped starting by itself.

I needed to do a complete service on the unit--change coolant, oil, filter, fuel filter, and air filter. I started by draining and replacing the coolant, then moved on to the oil and filter. I started the generator to warm up the oil and it quit after about two minutes. It started and ran at fast idle, then idled down for a few seconds and then quit.

I started it several times with the same results. The longer I waited between attempts, the longer it would run.

I completed the service and started the generator and it ran for about 5 minutes, then stopped.

First, is there anything I could have done at the inverter remote that could cause this behavior?

[slemnah]

Did you start it from the switch on the dash or or at the generator or did you start it from the generator panel? Try starting it from the generator panel and it may stay running. The inverter shuts it off if started from the dash switch unless you reprogram the panel.
Steve

[jacwjames]

Have you checked for blink codes to see why it is shutting down. Press the stop button down 3 times within 5 seconds. If there was a fault it will provide a blink code, note the number of blinks. Check your operating manual troubleshooting section and it explains the blink codes.

Hold the prime button down on the generator for ~1 minute, it may have some air in the system.

If mine sits for a long time it seems to want to do the same thing unless I prime for a long time.

[barmcd]

I'll purge it and check to see if there are any codes.

[barmcd]

I get 33 when I push the stop generator button so I'm assuming I have a bad temp sensor. Can anyone point me to where it's at on the unit?

[YC1]

It may have an air bubble. Watch this video for information. It is towards the end where it talks about overheating due to air.

https://www.youtube.com/watch?v=0LB5ZhvhXas

[barmcd]

Thanks Myron, the overflow tank had the right level in it so I didn't think to actually look in the radiator. It took nearly a full quart of antifreeze and has been running for 15 minutes now so I think that did it.

[jacwjames]

How much coolant did you drain out??

It takes more then 1 quart for the entire system.

When you filled the coolant did you pull the radiator fill cap completely out of the front cover???? It pulls out ~1 foot.

I know this because I made a huge mistake, I thought I had pulled it out enough but didn't and the hose was kinked. It would not take anymore coolant, when I started it did the same thing. I kept forcing it (I removed the heat sensor plug, BIG Mistake) and I actually got it hot and failed the engine. Had to replace generator with a used one $5K.

The temperature sensor is on top of the engine, passenger side, you have to remove the top cover to get to it. Located next to the thermostat.

[Coma]

Make sure the auto shut down is selected to manual.

[barmcd]

Originally Posted by jacwjames

How much coolant did you drain out??

It takes more then 1 quart for the entire system.

When you filled the coolant did you pull the radiator fill cap completely out of the front cover???? It pulls out ~1 foot.

I know this because I made a huge mistake, I thought I had pulled it out enough but didn't and the hose was kinked. It would not take anymore coolant, when I started it did the same thing. I kept forcing it (I removed the heat sensor plug, BIG Mistake) and I actually got it hot and failed the engine. Had to replace generator with a used one $5K.

The temperature sensor is on top of the engine, passenger side, you have to remove the top cover to get to it. Located next to the thermostat.

I drained out most of a gallon and thought I put in about the same. I bought a gallon container of coolant and couldn't get all of it into the generator so I put the old coolant in an empty 1 gallon bleach bottle. Normally I'd know exactly how much I took out and how much I put in, but since I didn't reuse the same container I didn't know exactly. In retrospect I probably took out almost a gallon and put in a little over three quarts.

I did pull the radiator cap and hoses all the way out. The large hose does tend to kink where it comes out of the frame and stop you from putting more coolant in the radiator.

I ended up running it a full two hours under load for it's monthly exercise. I like having a generator, but I don't know if we'll really ever use it since we don't boondock at all right now.

I'm glad it has an overheat shutoff because I sure would have burned it up if it didn't.

[barmcd]

Originally Posted by Coma

Make sure the auto shut down is selected to manual.

I have it on manual start and stop now.