Generator runs for 30 minutes to an hour and then shuts off and cannot be restarted

[andybree]

We had our generator on our 2014.5 serviced at 36 hours, and have turned it on and run it periodically since then, with no apparent problems. Prior to having it serviced, most of the time the generator was running, it was being used to run the AC (pulling 17 amps), with no problem. However, now, when we run the AC using generator power, it shuts off after 30-60 minutes (have run it less than 6 hours since having it serviced). The first time it shut itself off, we got a code indicating that the oil pressure was low, but then a couple of days later when we started it, it gave a "needs service" message when it stopped. Any ideas about what could be causing the problem?


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[Protagonist]

Originally Posted by andybree

Prior to having it serviced, most of the time the generator was running, it was being used to run the AC (pulling 17 amps), with no problem. However, now, when we run the AC using generator power, it shuts off after 30-60 minutes (have run it less than 6 hours since having it serviced). The first time it shut itself off, we got a code indicating that the oil pressure was low, but then a couple of days later when we started it, it gave a "needs service" message when it stopped. Any ideas about what could be causing the problem?

If it was serviced six engine-hours ago it shouldn't be low on oil, but since you got a "low oil pressure" indicator followed by a "needs service" indicator, being low on oil— and getting even lower— is the easiest possible answer to check. If you can reach the dipstick (probably have to drop the spare tire first) and check the oil level you'll know for sure. Don't try to run it again until you confirm that the oil level is okay.

If the oil level is okay, then the problem would be with the oil pump, which isn't really a user-serviceable item unless you can drop the whole generator and work on it at a bench.

[Titus]

Could be with the oil pump as Protagonist suggests, but I would not make that my next step in trying to fix the problem. Seems unlikely to me that the oil pressure would be OK for 30-60 minuutes then suddenly go low. More likely I would think (if it really is an oil pressure issue) is that the oil pressure sending unit is bad. After 30-60 minutes it could get hot and and encounter an electrical failure (short or open circuit) that then heals itself when it cools off. I don't know what is involved in replacing the sending unit (still may have to remove the generator), but certainly easier than replacing the oil pump.

[PSchw]

Mine did this 2 years in the row. Both times service at Airstream in Jackson Center OH. Both times the screw for oil removal was not tight and it tripped very little so if the oil was cold it worked ok if it got worm it would first start hesitating an later stop.
Added oil (what a job) and tightened the screw with a new seal washer which was obviously not done by Airstream.

[Nomad518]

It's unlikely you would get those indicators for the problem with this idea, and I'm not familiar with the generator in your rig, but does the gas cap for your generator have a vent that needs to be opened prior to running? If you forget to open that vent, a vacuum will be formed in the fuel line causing the generator to stop running after a short time.

[Protagonist]

Originally Posted by Nomad518

I'm not familiar with the generator in your rig, but does the gas cap for your generator have a vent that needs to be opened prior to running? If you forget to open that vent, a vacuum will be formed in the fuel line causing the generator to stop running after a short time.

You have no way of knowing this, but the Onan generator on an Interstate runs on propane and doesn't have a gas cap.

[Nomad518]

Thanks Protagonist! Like I said, I'm not familiar with the generator in these rigs.

I've had similar problems with my generators and outboard boat engines using external fuel tanks in the past. I found that I forgot to open that little valve on the fuel tank cap. Obviously not the cause of the problem here. I'll sit back and read the posts from those such as you who are better informed.

[andybree]

Thanks to all for your helpful replies and suggestions. When it stops raining here in this semi-arid and very thankful part of Texas, we'll (meaning my husband) get busy checking the oil and work from there.


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[73shark]

It's possible to check the oil level w/o dropping spare. I gained some space by backing to end of driveway and letting the rear hang over the street which gained me about 6" of space. Plenty to crawl under (chunked the tires first) and remove the inspection panel to get to the dipstick.

[Ron_CA]

Originally Posted by 73shark

It's possible to check the oil level w/o dropping spare. I gained some space by backing to end of driveway and letting the rear hang over the street which gained me about 6" of space. Plenty to crawl under (chunked the tires first) and remove the inspection panel to get to the dipstick.

Once you get under, probably not room enough to remove the dipstick without at least lowering the spare some. That was the case with my 2015 so maybe just on the latest chassis models? I got under just fine and unscrewed the dipstick but could not pull it out of the generator because it hit the tire.

[73shark]

Originally Posted by Ron_CA

Once you get under, probably not room enough to remove the dipstick without at least lowering the spare some. That was the case with my 2015 so maybe just on the latest chassis models? I got under just fine and unscrewed the dipstick but could not pull it out of the generator because it hit the tire.

Maybe AS changed the generator location slightly.

[73shark]

Or maybe Onan changed the location of the dipstick from my model.

[Ron_CA]

I think maybe they changed the location of the spare tire just slightly, thus not allowing enough clearance.

It looked as if there was room to have moved mine toward the rear up to about 2 inches which would have left plenty of room. It wouldn't have taken much.

[Boxster1971]

I just changed the oil in my generator. Getting the dip stick out was possible without removing the spare, but just barely. I had to wiggle it a bit to get it in and out. The worse problem on mine was that the drain plug was not centered in the shroud opening. That prevented me from being able to get a socket on the plug. I had to do a little body work with a hammer to get cleanse for a socket on the drain plug. Side benefit was all that pounding on the shroud loosened all the dried mud from my Alaska trip. Even the dip stick was covered with mud that I had to brush off before removing it the first time.

Removing the spare would have made serving the generator easier - I'll do that next time.


- - Mike
2013 Lounge EXT on 2012 Sprinter

[andybree]

After reading all the additional posts, we are ready to get out and do some exploring on the nether regions of our AI! However, it continues to, blessedly, rain! Looking forward to testing all your suggestions, and will get back to you with the results. Thank you all for your time and words of advice!

Jim and Cyn