Generator noise/vibration question

[mrchiefe7]

We have a 2020 Gulf Stream BT Cruiser 5240 with an Onan QG4000, Model 4KY-26100R generator. This model has a pull down murphy-bed located in the front. The generator is located directly under the bed. When we are camping without electric hookup and need to run the A/C or heater, the generator needs to be running and between the noise and vibration from the generator it is pretty hard to sleep. Has anyone been bothered by this same thing and were you able to come up with a solution to help lower the noise/vibration?

 

[Boat Bum]

I personally won't run my generator while sleeping. You can buy sound shielding and see what can be done with that.

 

[Rene T]

If you use sheilding make sure you don’t block any flow of the cooling air.

 

[Primerump]

We have a 2020 Gulf Stream BT Cruiser 5240 with an Onan QG4000, Model 4KY-26100R generator. This model has a pull down murphy-bed located in the front. The generator is located directly under the bed. When we are camping without electric hookup and need to run the A/C or heater, the generator needs to be running and between the noise and vibration from the generator it is pretty hard to sleep. Has anyone been bothered by this same thing and were you able to come up with a solution to help lower the noise/vibration?

only thing I can think of is to check the engine mountings, perhaps they are worn ?
my AF 25R has the generator at the rear, I don't run it overnight, only during the day.. so it's never an issue..

 

[old RV guy]

We have a 2020 Gulf Stream BT Cruiser 5240 with an Onan QG4000, Model 4KY-26100R generator. This model has a pull down murphy-bed located in the front. The generator is located directly under the bed. When we are camping without electric hookup and need to run the A/C or heater, the generator needs to be running and between the noise and vibration from the generator it is pretty hard to sleep. Has anyone been bothered by this same thing and were you able to come up with a solution to help lower the noise/vibration?

My guess is a 5 year old generator in a 5 yr old MH is doing exactly as it's intended. You might be able to fit some soundproofing to the underside of the floor above the unit, but it would be a chore and likely of negligible benefit. I'd be interested in comparison to another BT Cruiser to see if the noise and vibration is the same. Sometimes it just is what it is.

 

[Mark_K5LXP]

Identifying the primary path of the noise is step one - is it conducted vibration or exhaust noise? Likely both but you'd focus on the major one first.

The engine is on rubber mounts. They're quite compliant, if you start and watch the thing run with the cover off you can see the engine moving about independent of the enclosure.

If those are shot the engine can move against the housing, so that's something to check. Mine are 20 years old and still holding up OK though. Can't tell from the photos if the unit's support frame is rigid or if it's a drawer. Putting isolation mounts on that would help with some conducted noise.

Sound insulation added within the compartment can only help. Sound reflection from the ground underneath the generator will be a contributor. Putting a mat or some carpet underneath would help that. Redirecting the exhaust might make an incremental difference.

There's probably no one thing you could do that would make a huge difference, it would be several things done in aggregate that will net some improvement. You start with the easy stuff and work your way up until it's either quiet enough or it exceeds your attention span.

Mark B.
Albuquerque, NM

 

[gwinger]

It looks like the generator is hanging above the floor.
Having the generator hanging like that could contribute to the noise. Any of the mounting brackets and even the top supporting members being loose, would amplify any vibration.

 

[RV_Lee122]

A few years ago I was looking at RVs with a friend, he really liked that Winnebago class A
"National parks edition", but like yours it had the generator right under the bed. I pointed that out to him, he said "they haven't figured that out yet?"

I said, "no."

If you are running the furnace for heat you can fix that with a simple lithium battery set up but for AC I dont know what to tell you besides adding some dynamat where you can or ear plugs

 

[Kirk]

Putting isolation mounts on that would help with some conducted noise.

Since sound is actually is a vibration that propagates as an acoustic wave through a transmission medium such as a gas, liquid or solid, I would look for places where that vibration is conducted to the RV frame, first. It will probably be far more effective that any sort of insulation and adding insulation could easily create ventilation problems for the operation.

Have you owned the RV for a time, and this only recently started happening? If so, that would make me think that something has changed to transmit the vibration such as a rubber mount failure or something touching metal that should not. Even if you only recently bought it and the noise was already there, I'd still look for the same issue first.

 

[mrchiefe7]

Thanks for all of the replies. We got the unit last year and only been able to go on one long trip so fare. The generator only had about 34 hours run time on it when we got it. We are thinking about trying to install some sound insulation. But the generator is not installed an enclosed compartment just an angle iron frame, so there are not walls to install the sound insulation too. We can add additional battery for the heat is needed. When it is hot outside, and we want/need the A/C to sleep. We like to boondock/dry camp when every we can because of the cost at campground has gotten too high.

 

[No cats]

Maybe time for a portable quiet inverter generator big enough to run the AC the few time you may need it.

 

[John From Detroit]

I had an Onan Emerald series and frankly I could tell the generator was running but not a problem

How about just adding noise.. Specifically White noise. to your bedroom... Several devices on the market for that Some add specific sounds many have options. White noise your mind swiftly blocks and it in turn blocks other sounds.

Oh what is White noise v/s say Pink or blue?
White is 20-2000 hz a noise that contains all frequencies across the spectrum of audible sound in equal measure
a noise that contains all frequencies across the spectrum of audible sound in equal measure (pink and blue have more sound as you move towards one end or the other)

It is also the name of a movie Google is your friend.

 

[Kirk]

We like to boondock/dry camp when every we can because of the cost at campground has gotten too high.

When you watch it run, is there any sound of it vibrating against the metal support or some other metal? I would expect that the noise would be the same as when inside, but louder, unless the problem is that it bumps against the door when it is closed. We have had 2 class A RVs that had Onan generators, and both were mounted similarly to yours with the bottom open as that was the source of cooling air. In fact, both manuals said not to operate them under load with the door open. The Onan's do make some noise but it was never a problem for us to sleep inside and the first one was actually under the head of our bed. Of course how loud something can be a rather subjective thing so its difficult to share what the usual noise would be.

 

[Primerump]

A few years ago I was looking at RVs with a friend, he really liked that Winnebago class A
"National parks edition", but like yours it had the generator right under the bed. I pointed that out to him, he said "they haven't figured that out yet?"

I said, "no."

If you are running the furnace for heat you can fix that with a simple lithium battery set up but for AC I dont know what to tell you besides adding some dynamat where you can or ear plugs

Agree, it would be common sense to put the generator as far away as possible from sleeping quarters.. however, this IS the RV industry we are talking about..

 

[Mark_K5LXP]

I always thought the Cummins/Onan 4K was antithetical to it's name - it's neither 'micro' nor 'quiet'. A portable generator big enough to run A/C wouldn't be terribly convenient to store or schlep around. Then there's the notion of carrying around 2 equally capable generators. Sometimes I'll take my inverter set along though, when I know I'll be off grid for longer than the batteries will hold out. I'll set it up as far as my 50' cord can go and let it putter in eco mode to bring the batteries back up as needed. You can barely hear it run outside and not at all inside.

Mark B.
Albuquerque, NM

 

[No cats]

Portable generators have come a long way. Here is a good viable choice. Weight is 51.8 Lbs plus fuel. That is about the same weight as one of my old 6V GC batteries.

 

[RV_Lee122]

I always thought the Cummins/Onan 4K was antithetical to it's name - it's neither 'micro' nor 'quiet'. A portable generator big enough to run A/C wouldn't be terribly convenient to store or schlep around. Then there's the notion of carrying around 2 equally capable generators. Sometimes I'll take my inverter set along though, when I know I'll be off grid for longer than the batteries will hold out. I'll set it up as far as my 50' cord can go and let it putter in eco mode to bring the batteries back up as needed. You can barely hear it run outside and not at all inside.

Mark B.
Albuquerque, NM

Exactly. Its quite remarkable that a one cylinder engine, in such a large package can make that much noise. The fact they call it quiet is just laughable. Ive seen cheap portable generators that you can barely hear running, for contrast