Generator noise mitigation?

**TerryH** · 01-22-2021, 08:34 PM

Wondering if anyone ahs successfully lowered the noise level of the Cummins/Onan 4k genet? It's under the bed slide in our 31G and is much to noisy for my taste. Considering something like Dynamat sound insulation inside the compartment. Perhaps an axillary muffler? Anyone done anything they'd care to share?

**AZCamper** · 01-22-2021, 08:38 PM

Originally Posted by TerryH

Wondering if anyone ahs successfully lowered the noise level of the Cummins/Onan 4k genet? It's under the bed slide in our 31G and is much to noisy for my taste. Considering something like Dynamat sound insulation inside the compartment. Perhaps an axillary muffler? Anyone done anything they'd care to share?

The funny thing is I think it’s quieter under load. Hopefully there are some tips to quiet it.

‘21 Momentum 31G

**TerryH** · 01-22-2021, 08:47 PM

Originally Posted by AZCamper

The funny thing is I think it’s quieter under load. Hopefully there are some tips to quiet it.

‘21 Momentum 31G

I'm going to investigate further tomorrow. Perhaps I'm just spoiled by my Predator 3500 but the Onan just seems terribly loud and has a lot of vibration. It rattles the carousel plate in the microwave so much I had to take it out to preserve my sanity.

**AZCamper** · 01-22-2021, 08:53 PM

Originally Posted by TerryH

I'm going to investigate further tomorrow. Perhaps I'm just spoiled by my Predator 3500 but the Onan just seems terribly loud and has a lot of vibration. It rattles the carousel plate in the microwave so much I had to take it out to preserve my sanity.

We went from a Yamaha 2K for years, so yeah it’s a transition lol. I am a sound sleeper so I can fall asleep with it on. We haven’t had it shake the trailer that bad, but it’s too loud to be in the bedroom and do conference calls. Luckily the BB batteries and inverter last all day while we work.

‘21 Momentum 31G

**el Rojo** · 01-23-2021, 07:27 AM

A couple of things. This Gen turi pipe will move your exhaust port above your roof line. Most of us use them because of fumes but it also moves some of the sound. https://www.campingworld.com/camco-g...tem-14041.html

Also check your altitude adjustment by the carburetor. Check your mounts on the unit. Spark plug tight? Ours doesn't vibrate bad at all, but we are further from it in our 5th wheel.

Now the washing machine is a different story, the whole camper shakes. It used too embarrass me, now as I get older it's like a feather in my cap, LOL.

**1HDRIDER00** · 01-23-2021, 07:48 AM

I have a 2018 376TH. I use a pipe that takes the exhaust above the roof. Also, the engine fan makes more noise than the engine exhaust. When new, the tail pipe was installed incorrectly which caused the muffler to viberate against the generator housing. It made a bit of noise but the vibration was excessive. Once I readjusted everything it made a world of difference.

**Txfivver** · 01-23-2021, 08:33 AM

I think I would get the generator checked out first, It should not noticeably vibrate the trailer nor be that loud inside. My 5500 is mounted right under the front bedroom and when running is just a white noise type sound, even more so when the front a/c clicks on. It can not be felt in the floor of the bedroom at all. You may have a bad mount, they are mounted on springs and you should be able to rock it around pretty well by hand. Just a thought... I'm sorry but I could not bear the sight of that ugly exhaust pipe running up the street side of my trailer lol!

**TerryH** · 01-23-2021, 09:31 AM

Originally Posted by Txfivver

I think I would get the generator checked out first, It should not noticeably vibrate the trailer nor be that loud inside. My 5500 is mounted right under the front bedroom and when running is just a white noise type sound, even more so when the front a/c clicks on. It can not be felt in the floor of the bedroom at all. You may have a bad mount, they are mounted on springs and you should be able to rock it around pretty well by hand. Just a thought... I'm sorry but I could not bear the sight of that ugly exhaust pipe running up the street side of my trailer lol!

Thanks. The trailer is headed back into the dealer for some warranty work in 3 weeks. I'll have them take a look at it then. I'm still going to check it over myself first. I don't see too many complaints on the 5.5k but seems like most everyone with the travel trailer style toy haulers have complaints about the Onan 4k. This one does seem particularly obnoxious. It is a concern for the exhaust to be directly under the bed slide. That is not a good idea.

**el Rojo** · 01-23-2021, 09:41 AM

One more thing on your genset. Look at the identification plate and see how many amps it will deliver. The 5.5 that we have only puts out 46 amps and the EMS inside our camper gets squirrely at 44 amps, so I watch the amps I'm pulling and try to stop at 39 amp draw. I originally thought a 5.5 would pull the whole camper coming from diesel pusher but that's not the case here. Once I learned what it would all my problems stopped...just another learning curve of the camper.

Red