Onan 4000 Question

[Jopopsy]

I notice that on many other MH manufacturer’s Onan 4000 installs, they included a baggage door that is vented; there have been many posts from various makes over the years regarding the Onan 4000 (and others) overheating; apparently the vent in the door allows it to breathe better.

Any Spirit/Minnie Winnie owners out there w/ stalling Onan generators when its hot out? I can’t imagine Winnie did something different that saves them from this problem, though perhaps I’m mistaken. Maybe they offset the genny off the door a little more to allow more breathing room?

I was surprised to see the solid door on a 2022. Wondering if I’m heading for issues down the road.

Thanks !

[creativepart]

Back in 2015 I had a Class C with the Onan 4000. I did not have a vented door - Onan says they designed their enclosure to efficiently provide air cooling when all closed up. Even have signs to not leave the genset's door off as it will cause over heating.

But, that genset would die when running it while I drove any time the temps topped 95.

I took it to Cummins. They started it in the parking lot and let it run 8 hours and did that 2-days in a row (in over 90 degree heat) and it never died. They used up 1/2 a tank of gas with that little "test." They pronounced it not a real problem.

I don't think mine ever stalled when using it at a campsite, but then we don't camp in 95 degree weather without having shore power.

I feel certain it was a vapor lock issue but I don't think it had anything to do with the unvented door.

[Jopopsy]

I’d imagine its more of an issue when underway since you have the asphalt, engine heat, and other conditions making things worse. At the campsite, I wonder if running w/ the baggage door open would end up w/ the baggage door too close to the genny exhaust …. Hrm something to consider when pick ours up.

I suppose a benefit to a shorter coach - the chassis AC should be able to keep things comfortable while underway. Especially if you pop a vent cover to help move the air through.

[creativepart]

Unless your Operator's Manual tells you to do something specific I would not freelance on anticipating a problem that other folks are not reporting. In other words, don't over think it.

[powercat_ras]

Onan 4000 is air cooled and the hot air exits thru the bottom from around where the exhaust pipe exits. In some RVs where the sidewall and back wall extends well below the bottom of the generator, like on my Vista, on days with no wind the hot exhaust air can rise right back up and get drawn in as intake air and it will overheat on hot days due to this.

Opening the un-vented sidewall door on my Vista can reduce this but it greatly increase the noise level. As was said you can not remove the Green door on the side of the generator for any length of time or you will get an overheat shutdown as the air won't be forced thru the generator to cool the engine and generator sections of the Onan.

I bought a 4" x 12" rectangular to round furnace duct adapter and installed it onto the bottom of the generator (some trimming required). This directs the hot air farther away from the generator hot air intake. No overtemp shutdowns since.

[Twpinaz]

I have run my onan 4000 on the road throughout Arizona in the 100+ temps traveling from home to campgrounds up north to cool off for a couple of years. Running the genie to power roof top AC for 5-6 hrs on the road is common and have never had it overheat. I do make sure I perform all recommended maintenance on it.

[Jopopsy]

Originally Posted by powercat_ras

I bought a 4" x 12" rectangular to round furnace duct adapter and installed it onto the bottom of the generator (some trimming required). This directs the hot air farther away from the generator hot air intake. No overtemp shutdowns since.

How did you connect this to the gennie? In the event mine shuts down from the heat I’ll have the solution in my back pocket.