Onan 5.5 stress test

**huntindog** · 08-31-2022, 02:10 PM

I did a hot weather stress test of my 5.5 onan's ability to run all 3 Colman 15K ACs.
It was 100 degrees outside, the mostly black Momentum was in full sun, and the interior was heat soaked to 109 Degrees. All ACs started without incident with the voltage sagging to 120V for an instant, on #3 then stabilizing at 122V
I ran it for 30 minutes and the inside temps dropped to 96 degrees, with outside temp climbing to 102 degrees, and it was actually quite comfortable with the cold air blowing out the vents. I went outside to check on the Onan, and it smelled hot. I shut every thing down and remembered a member here having an overheat problem. It was solved with an Onan vent/baffle that directs the hot exhaust air away from the cold air intake, to prevent it from recirculating. The part is now on order, and I am sure that will fix it.

This was actually a pretty hard test, as I would never let the coach get that hot if I was using it.
So far I have only had to run the ACs when under tow (so air recirculating on the highway would not be an issue) to keep the interior temps reaonable when close to home, in Phoenix. Camp is generally in the high country with cooler temps

**Brother_Bluto** · 09-01-2022, 08:48 PM

Do you have a picture of this baffle? Part Number?

**huntindog** · 09-02-2022, 06:13 PM

Originally Posted by Brother_Bluto

Do you have a picture of this baffle? Part Number?

I can't do pics here.
It is Onan part# 026-00495.
Google that and pics are easy to find. Best price I found was at Advanced service and parts LLC.
66.68 shipped to me. Most places are around 90.00 plus shipping.

**el Rojo** · 09-03-2022, 07:47 AM

Do you think one of these would have helped instead. I have one and when the wind is blowing the exhaust back in the rig they're worth twice that much.

**huntindog** · 09-03-2022, 10:37 AM

Originally Posted by el Rojo

Do you think one of these would have helped instead. I have one and when the wind is blowing the exhaust back in the rig they're worth twice that much.

I do not see what one of these is.
But I think we are talking about two different things.
The exhaust air I am talking about is the cooling air. Not the combustion air.
This is an air cooled motor, with an intake hole for cool air and an exhaust hole for where the now hot air exits. In some cases the heated air has been looping around and entering the cold air side. The Onan side baffle prevents this by directing thr hot air in the other direction.

**el Rojo** · 09-04-2022, 06:53 AM

Originally Posted by huntindog

I do not see what one of these is.
But I think we are talking about two different things.
The exhaust air I am talking about is the cooling air. Not the combustion air.
This is an air cooled motor, with an intake hole for cool air and an exhaust hole for where the now hot air exits. In some cases the heated air has been looping around and entering the cold air side. The Onan side baffle prevents this by directing thr hot air in the other direction.

This is an extension of your exhaust pipe that takes the exhaust above the roof line of your camper. Sorry, I looked it up but forgot to post the link.
https://www.campingworld.com/camco-g...tem-14041.html

**el Rojo** · 09-04-2022, 06:55 AM

Can you post a link to your baffle? I think I found it.

https://www.rockymountaingeneratorsu...arge-Vane-Side

**huntindog** · 09-04-2022, 02:29 PM

Originally Posted by el Rojo

This is an extension of your exhaust pipe that takes the exhaust above the roof line of your camper. Sorry, I looked it up but forgot to post the link.
https://www.campingworld.com/camco-g...tem-14041.html

I have seen those. I have never had the issue though.

**huntindog** · 09-04-2022, 02:33 PM

Originally Posted by el Rojo

Can you post a link to your baffle? I think I found it.

https://www.rockymountaingeneratorsu...arge-Vane-Side

That is it. A little pricier that what I paid..... But I do not have it yet. and no shipping info either. When I went back to their website and searched the part number just now, it says item not found.

I will give it some time, but it is not looking good so far.

**Brother_Bluto** · 09-05-2022, 12:49 PM

Originally Posted by huntindog

I can't do pics here.
It is Onan part# 026-00495.
Google that and pics are easy to find. Best price I found was at Advanced service and parts LLC.
66.68 shipped to me. Most places are around 90.00 plus shipping.

Thanks. I was going to ask if you drill the holes for mounting... but found this NHTSA document from 2017 and see to use self-tapping screws. https://static.nhtsa.gov/odi/tsbs/20...54771-9999.pdf