Just Jim Posted January 27 Share Posted January 27 I have a "quiet diesel" 10k Onan that actually is not really all that quiet. While camping I've noticed other generators that are very quiet and I'm just curious if anyone has replaced the muffler in order to get a quieter experience? This is a low priority modification as I've got much bigger "fish to fry" as the saying goes, but again was just curious if this was a project I could at least put on the agenda. 1 Link to comment Share on other sites More sharing options...
Chargerman Posted January 27 Share Posted January 27 I would suggest that the noise you are hearing is the generator itself and not the exhaust? Link to comment Share on other sites More sharing options...
Just Jim Posted January 27 Author Share Posted January 27 I'm sure some of the noise is the inherent diesel sounds, but there is considerable noise from the exhaust pipe as well. Again just curious if anyone has ever tried to quiet it down with a different muffler. Next time I'm camping and find a really quiet one, I'm going to ask the owner what kind of generator it is... 1 Link to comment Share on other sites More sharing options...
Bill R Posted January 27 Share Posted January 27 (edited) 5 hours ago, Just Jim said: I'm sure some of the noise is the inherent diesel sounds, but there is considerable noise from the exhaust pipe as well. Again just curious if anyone has ever tried to quiet it down with a different muffler. Next time I'm camping and find a really quiet one, I'm going to ask the owner what kind of generator it is... I purchased one of these if I am staying somewhere and using the generator for more than a day. It does quiet the exhaust, plus it exhausts above the RV so you do not have fumes at ground level. https://www.amazon.com/FDSNH-Generator-Exhaust-Venting-Systems/dp/B09FG4G8PL/ref=sr_1_2_sspa?crid=48ZD1R2YOM3T&keywords=rv+generator+exhaust+stack&qid=1706377340&sprefix=rv+generator+stack%2Caps%2C121&sr=8-2-spons&ufe=app_do%3Aamzn1.fos.f5122f16-c3e8-4386-bf32-63e904010ad0&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&psc=1 Edited January 27 by Bill R 1 Link to comment Share on other sites More sharing options...
Just Jim Posted January 27 Author Share Posted January 27 Yes. I use one too Link to comment Share on other sites More sharing options...
96 EVO Posted January 27 Share Posted January 27 7 hours ago, Just Jim said: I have a "quiet diesel" 10k Onan that actually is not really all that quiet. While camping I've noticed other generators that are very quiet and I'm just curious if anyone has replaced the muffler in order to get a quieter experience? This is a low priority modification as I've got much bigger "fish to fry" as the saying goes, but again was just curious if this was a project I could at least put on the agenda. I 'think' the quieter diesel gen's your comparing yours to are smaller units that run at variable speeds depending on load. The 10 & 12.5K units run 1800RPM, from no load to full load! 2 Link to comment Share on other sites More sharing options...
Venturer Posted January 27 Share Posted January 27 FWIW I don't know why, but our 12.5KW Onan in our 06 Executive seems quieter inside and outside than our 10 KW was in our '13 Allegro Bus. The inside level is probably due to coach construction. Not sure with the outside noise level. 1 Link to comment Share on other sites More sharing options...
Georgia Mike Posted January 27 Share Posted January 27 I had a 7.5 Onan in my old motorhome and now the 10K and they both are about the same noise to me. they are both pretty quiet. Link to comment Share on other sites More sharing options...
Bobkat11208 Posted January 27 Share Posted January 27 4 hours ago, Bill R said: I purchased one of these if I am staying somewhere and using the generator for more than a day. It does quiet the exhaust, plus it exhausts above the RV so you do not have fumes at ground level. https://www.amazon.com/FDSNH-Generator-Exhaust-Venting-Systems/dp/B09FG4G8PL/ref=sr_1_2_sspa?crid=48ZD1R2YOM3T&keywords=rv+generator+exhaust+stack&qid=1706377340&sprefix=rv+generator+stack%2Caps%2C121&sr=8-2-spons&ufe=app_do%3Aamzn1.fos.f5122f16-c3e8-4386-bf32-63e904010ad0&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&psc=1 Gen-Turi’s (or equivalent) are the best! We’ve turned so many newbies onto them while boondocking at races. And they do raise the “noise” above and away from the coach. Link to comment Share on other sites More sharing options...
Mike Barrett Posted January 28 Share Posted January 28 Was standing next to a 10k onan that clearly had some sort of aftermarket 'hush box' installed. Exhause looked standard but really, rally quite. I am thinking they installed some sound insulation boards 'in' the cage that houses the generator. I recently had to replace my generator (went w/ a durawatt out of leesburgh) and they have a pretty quite unit (13.5k), the version 2.0 was much quiter and it was based more on the mounting that the muffler. Link to comment Share on other sites More sharing options...
Just Jim Posted January 28 Author Share Posted January 28 1 hour ago, Mike Barrett said: Was standing next to a 10k onan that clearly had some sort of aftermarket 'hush box' installed. Exhause looked standard but really, rally quite. I am thinking they installed some sound insulation boards 'in' the cage that houses the generator. I recently had to replace my generator (went w/ a durawatt out of leesburgh) and they have a pretty quite unit (13.5k), the version 2.0 was much quiter and it was based more on the mounting that the muffler. Thanks Mike, I'll have to do a search for a "hush box"... no telling what kind of info I'll get. LOL Link to comment Share on other sites More sharing options...
Mike Barrett Posted January 28 Share Posted January 28 Hush box is an sound insulated box that the prevost etc put around their generators. They build it in as part of the engineering etc etc. I am toying with a diy attempt for the cage around the gennie slide Link to comment Share on other sites More sharing options...
LakeBob Posted January 29 Share Posted January 29 I have a 10K Onan and when I purchased the coach it was quite loud, wasnt sure, thought it was more of a mechanical noise than exhaust. The generator is powered by a 3 cylinder ISUSU diesel engine. The engine is supported by 3 motor mounts. The generator box is mounted to the steel movable frame with 4 rubber bushings. I asked my local truck repair shop to check the generator during a major fluid and filter change. The exhaust was in good condition. What they did find was a small piece of 2 x 6 lumber jammed in between a broken motor mount and the engine! I had them replace all the mounts and the rubber bushings. It's like a new unit, much quieter, sounds similar to an outside central air unit. I would suggest you check all the motor mounts and generator mount bushings. I've also seen some older coaches, American Coach, Country Coach, that have a thick, 1/4"?, rubber mat attached to the forward upper generator mounting frame and laying over about 3/4 of the top of generator box. This looks like a simple solution to help dampen some of the mechanical vibration. This is on my list of repairs and updates when we return home in the spring. Link to comment Share on other sites More sharing options...
Mike Barrett Posted January 29 Share Posted January 29 Onan has used Kubota engines for a long long time - DuraWatt uses Isuzu. 3 point mounts are oddly much quieter than 4 point mounts (I am not an engineer, just observant) the hyper expensive coaches actually have small airbags as mounts, not ready to go to that level. clearance, etc wasn't built for that. 1 Link to comment Share on other sites More sharing options...
LakeBob Posted January 29 Share Posted January 29 Hmm, not sure where I got the Isusu info, think maybe the truck shop, perhaps I do have a Kabota. Yes, I've seen the small airbag mounts on my friends older Prevost. His generator is mounted mid coach in a well insulated box as described above. Very quiet installation. Thought about a retrofit as well, it would be a major project with the limited space in the box. 1 Link to comment Share on other sites More sharing options...
RedSectorA Posted January 29 Share Posted January 29 14 minutes ago, Mike Barrett said: Onan has used Kubota engines for a long long time - DuraWatt uses Isuzu. 3 point mounts are oddly much quieter than 4 point mounts (I am not an engineer, just observant) the hyper expensive coaches actually have small airbags as mounts, not ready to go to that level. clearance, etc wasn't built for that. I have an Onan 10kw HDCAA that uses a Isuzu engine. Even in the Onan service manual page 3 for that unit you can clearly see the Isuzu marking on the picture of the engine. Link to comment Share on other sites More sharing options...
96 EVO Posted January 29 Share Posted January 29 Your '09 model year coach likely has the Kubota engine. Link to comment Share on other sites More sharing options...
Mike Barrett Posted January 29 Share Posted January 29 it was - prior owner cratered it, and tried some sort of frankenstien rebuilt that was cratered when I bought it. Replaced w Durawatt 13.5k which as the Isuzu engine. Which works pretty darn well I might add. Link to comment Share on other sites More sharing options...
96 EVO Posted January 29 Share Posted January 29 1 minute ago, Mike Barrett said: it was - prior owner cratered it, and tried some sort of frankenstien rebuilt that was cratered when I bought it. Replaced w Durawatt 13.5k which as the Isuzu engine. Which works pretty darn well I might add. Yeah, my comment was for LakeBob. Link to comment Share on other sites More sharing options...
Gweedo Posted January 30 Share Posted January 30 Gen-turi much quieter and no fumes if your windows are open. how many hours on the gen Link to comment Share on other sites More sharing options...
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