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.

[KJINTF]

Guess everyone's experience is a bit different
For me the newer Onan/Cummings gensets are pretty much junk
Suggest you purchase a Yamaha or Honda inverter style
The old 1987 two cylinder pressurized oil system with a spin on oil filter was wonderful and far better than today's Onan/Cummings single cylinder splash oiling systems which are JUNK - IMHO

[pnichols]

coolbreeze01,

Regarding the installation of improved isolation mounts for an Onan RV generator:

Make sure you check the Onan installation manual for your model to see the specifications for what vertical and horizontal G's a mount must be able to withstand. Then pick the best isolation mount you can afford that's both the right size for installation convenience, and vertical/horizontal G-rated accordingly.

[coolbreeze01]

pnichols wrote:

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

Thank you!

[dougrainer]

As to the OP and his noise concern. I will bet the install is the problem. The microlite is a popular model on Class B and Class C motorhomes, and they are installed slightly different than a 5th wheel and I get no noise complaints on Motorhome customers. Doug

[gandude]

Wow, camp on Onan day!

Ours is quiet. I think installation has a lot to do with noise along with tuning as a previous poster mentioned. The microwave is louder when running inside the trailer than the generator. Our Onan was there for us when I remodeled the house kitchen and during power failures. Guess I'm lazy as toting portables around is not our cup of tea, along with refilling gas and gas cans. The Onan has its quirks, but we have adjusted for them. It probably could be better, but we are happy the way it is.

My big noise complaint is the damn blower for the heater. That thing is loud!

[TEXAS]

At least you won't run out of quarters.

[gotsmart]

My Onan MQ 4K was built in Fridley, MN in April 2004.

Model: 4KYFA26100K

Kilowatts: 4 = 4000 (4000 Watts)
Product Family: KY
Starting method: F (remote startable)
Voltage & Frequency code: A (120 volt, 60-Hz)
Specification number: 26100 (code for options & special features)
Specification letter: K (Used to identify major design or manufacturing changes)

-------
It has 1,070 hours on the clock and there's nothing small or quiet about it. It starts up every time. I wouldn't have it any other way. Why go to a cheap motel and feed the machine quarters to vibrate the bed when all I have to do is turn on the genset? :B :W

[TEXAS]

Those are just a few that I have worked on.True there are many that have had no problems. But it is hard to tell a customer. That his new generator with only 55 hours on it. Is destroyed and out of warranty.

Or have Onan refuse warranty. On an air filter assembly. On a generator with only 51 hours. Because they claim he broke it. You could clearly see where the welds broke.

Or that the ten minute starter swap out. Is going to take two hours. Because you have to pull the unit to get to anything.

[pnichols]

Billy (TEXAS),

That data above came from how many tens of thousands of (late model) 4K MicroQuiet Onans out in the field?? :h

[TEXAS]

The new Onans will never come close to the hours of service. That the old Onans hold. Some of the problems I have seen.

55 hours KY broken valve destroyed engine.
51 hours air filter assembly fell apart.
160 hours Stator shorted out.
175 hours starter gear jammed up. Destroyed starter
KV unit
89 hours starter shorted out.
200 hours control module stopped working.
181 hours Magnets fell off of flywheel. Ripped out ignition module

[Wayne_Dohnal]

Here's a thread about the Onan valve spring problem Onan broken valve spring

And a link to the service bulletin http://www.irv2.com/forums/attachment.php?attachmentid=3548&d=1269626081

[pnichols]

64thunderbolt wrote:
previous 5er had a solid compartment door with the floor open for air.

That's exactly how Winnebago installed the Onan 4K MicroQuiet in our Class C.

I notice very little noise coming out of the exhaust ... 80% of the noise is from cooling airflow.

[64thunderbolt]

90% of the noise is in the installation. Fan noise. previous 5er had a solid compartment door with the floor open for air. It was 50% quieter than the one I own now with solid floor & vented compartment door. Put your ear close to the exhaust and you will see. Thinking of removing the gen and opening the floor and closing off the vent in the door.

[pnichols]

Wayne Dohnal wrote:
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.

Huuuuh??

That's sure not evident reading here in the RV forums. Those MicroQuiets are talked about everywhere and often with respect to the high hours one can put on them. I'm counting on high hours from ours!

I do use Mobil 1 EP oil in ours even though it's not an inexpensive oil, but who cares since you only have to use 1.6 quarts to change it? I also exercise ours every month.

Maybe we need a new thread on how short-lived some 4Ks are. :h