Loud Onan 4K Genny

[N-Trouble]

So I recently purchased an new 5er that has a built in Onan 4K generator and am disappointed at how loud it is. Onan really should drop the term "MicroQuiet" from this unit because there is nothing quiet about it IMO. My biggest complaint is it runs at a constant high RPM regardless of load. Why is it that this high dollar generator doesn't have a "SMART" mode like many of the lower cost portable units that adjust RPM based on load?

Even though I don't need the extra wattage, I'm seriously considering selling it and replacing with an Onan 5500 which is MUCH quieter.

[pnichols]

coolbreeze01 wrote:
Thanks for the idea, now to find the materials.

Here's one source for sound proofing material from the marine world (there are plenty more sources):

http://www.soundrite-acoustics.com/engine-room-boat-soundproofing-vinyl-foam_2.aspx

Here's one source for better isolation mounts than what usually come with Cummins ("Onan") generators as mounted by the RV manufacturers (there are other sources):

http://www.avproductsinc.com/index.html

[coolbreeze01]

" marine grade sound absorbing material all around the inside walls of their generator cabinets and high-quality vibration dampeners where they screw it down."

Thanks for the idea, now to find the materials.

[Wayne_Dohnal]

Never mind how today's Cummins's "Onan wannabe" generators are cooled, or oiled, or filtered, or how many cylinders they have ... how RELIABLE are they?

Mine broke both valve springs at about 20 hours. There were hundreds, perhaps thousands of KY series generators that suffered the same fate at various Hobbs readings. I was lucky that my damage was limited to the springs. A lot of them sucked a valve and required total replacement.

[pnichols]

Never mind how today's Cummins's "Onan wannabe" generators are cooled, or oiled, or filtered, or how many cylinders they have ... how RELIABLE are they?

From everything I read, they can be good for thousands and thousands of hours. I believe that's the main thing I care about and what I think I mainly spent my generator dollars for when I bought the motorhome.

The problem with Cummins "MicroQuiet" noise and/or interior vibration is installation corner-cutting by the RV manufacturer. It's the usual story -> for a few dollars more manufacturers could use marine grade sound absorbing material all around the inside walls of their generator cabinets and high-quality vibration dampeners where they screw it down.

Honda's attempt at offering a built-in RV generator turned out being loud and not an inverter generator ... they essentially only made a half-hearted attempt at entering and staying in the RV market, IMHO.

[KJINTF]

My Honda EX5500 is water cooled and a very nice machine as compared the Onan junk of today

[TEXAS]

Best I recall Honda RV units. Were water cooled with an electric cooling fan. That had a high failure rate. Made a low droning sound that would get on your nerves. Plus the price was not cheap.

You are correct Cummins bought a good company and put it in the ground. Destroyed a company that had been around since 1925. A company that backed up their product. Where the customer came first. Today it is all about the money. Screw the customer.

[KJINTF]

It's not Onan - Today it's Cummings - they destroyed the Onan brand

I had a wonderful 2 cylinder 4 stroke 4Kw genset, pressurized oil system with spin on filter in the late 80's

My new 4Kw micro quiet. is a POS, a single cylinder splash oil system, no oil filter no pressure aka JUNK!!!!!!

My belief is Cummings destroyed the Onan brand

[N-Trouble]

olygene wrote:
I kinda wish Honda would start building generators for RVs. Then maybe Onan would start putting more money into planning and engineering gens for RVs.

I think that is the main problem. Onan pretty much has a monopoly on built-in gennies with no real competition so they continue to use 20yr old (non-inverter)technology and charge us a pretty penny for it.

Would love to see someone come out with an inverter type 4K to compete with Onan's so called "Micro Quiet" genny.

[MrWizard]

Honda did.. and they quit..didn't sell enough of them to RV MFG

[olygene]

I kinda wish Honda would start building generators for RVs. Then maybe Onan would start putting more money into planning and engineering gens for RVs.

[pnichols]

RJsfishin wrote:
If its 90+ degs, who cares about noise, its the stayin alive that matters.
If its cookin my tv dinner, who cares about noise, its only a few minutes.
If its charging batteries, DON"T,.....get a Honda,....or solar.

That just about matches how we think of our built-in generator. I might add that it's also an excellent emergency backup for a failed or out-of-fuel propane system.

For sun-or-no-sun charging of our batteries we bring along a very quiet Honda EX650 and the main engine's alternator.

[RJsfishin]

If its 90+ degs, who cares about noise, its the stayin alive that matters.
If its cookin my tv dinner, who cares about noise, its only a few minutes.
If its charging batteries, DON"T,.....get a Honda,....or solar.

[pnichols]

N-Trouble wrote:
I still feel most of the noise is coming from the motor (not exhaust).

The noise from the 4K Onan in our Itasca is the opposite. Most of it's noise is the swooshing sound of it's cooling air. Engine noise seems very low considering it maintains on tap an instant 4000 watts of output.

I don't think all RV 4K Onans are installed the same. The one in our Class C is well up inside it's cabinet with none of the bottom of the Onan showing below the RV's sidewall. Our traveling companions have a 4K in their Class C that has the bottom 3-4 inches of it showing below the RV's sidewall - and it is MUCH louder than ours both inside and outside their Class C RV.

We have even been able to sleep with our Onan running most of the night powering the air conditioner in the extreme heat and humidity of the Southern U.S. in August.

Inside the RV, the Onan noise from ours of course can be heard but we can easily tolerate it for hours-long runs of the air conditioner. The RV floor above where the Onan hangs also deadens it's sound well using a thick carpet and pad to keep interior noise and vibration low. However, our Onan did quiet down and smooth out just a bit more after I installed a special spark plug in it and switched it's oil to a high-$$$ synthetic several years ago.

One poster in these forums has mentioned getting his built-in Onan sound down to 56dB (some Honda portables are 53dB at low power output) using sound deadening material inside it's cabinet and upgrading the engine mounts for it.

But I agree .... a 4KW variable speed inverter generator of Onan quality would be a good improvement.

[N-Trouble]

I found this which may help https://www.youtube.com/watch?v=gQboSPqKtfE

Anyone have any luck with one of these?

I still feel most of the noise is coming from the motor (not exhaust). I may also look at adding some sound deadening material inside the genny compartment.

[Wayne_Dohnal]

I say exactly the same thing about my factory installed micro"quiet". Others say they are really quiet and the difference is the installation. When I'm boondocking I carry an eu2000i to charge the battery. For short times like running the microwave I just put up with the noise. It is pathetic IMO that the current built-ins haven't caught up to 10+ year old consumer technology.