Loud Onan 4K Genny

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

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.

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.

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

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

" 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.

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.

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.

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

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.