Diesel Generator Fumes

[Gadget Man]

My Onan 7500 genset emits a great deal of strong diesel exhaust fumes, especially compared to a newer diesel genset or that of my RV's engine. Is there anything I can do to help cut down on the fumes?

Craig

[Bumps]

Great question. I have the same genny and same observation... \ken

[dvmweb]

Even after a good warm up? Sooty exhaust?

[Gary RVRoamer]

Diesel exhaust is smelly, especially the non-turbo engine used in a generator. Most of the problem is that the exhaust is right along side and drifts in via windows and slide seals. Assuming it is running correctly (air & fuel filters clean, etc) there proably isn't much to do except to add a Genturi-style exhaust pipe to take it up above the roof line.

[Bumps]

Not so much soot as fumes. Did full genny service before storing it for the winter, and it starts right up (after holding switch for 5 secs, or so); by "all appearances" it is working properly. It's just smelly. \ken

[Gadget Man]

Originally Posted by Gary RVRoamer

Diesel exhaust is smelly, especially the non-turbo engine used in a generator. Most of the problem is that the exhaust is right along side and drifts in via windows and slide seals. Assuming it is running correctly (air & fuel filters clean, etc) there proably isn't much to do except to add a Genturi-style exhaust pipe to take it up above the roof line.

I do all of my own maintenance, so everything is up to date. You are correct, the Gen-Turi is about the only thing that seems to help, but I only take the time to put it together when we are boondocking, which is rare. I'm just wondering why the newer diesel gensets don't have the same heavy fume. Do they have cat converters? Case in point, I installed an Aero muffler on my RV engine two years ago. I instantly noticed a change in the engine's exhaust odor. It smelled the same as the genset. The factory muffler had an internal cat converter, which I can only assume helped with the emission odor. The newer gensets being built have a lighter odor much like an engine with a cat converter, so I’m wondering if they do in fact have them. (FWIW, I plan to remove the Aero muffler as the heavy exhaust fumes fill up the cab of our toad. My wife said it is also impossible to drive behind the RV since I installed the Aero, as the exhaust fumes choke her out. Since I’ve seen no performance gains, I plan on re-installing the factory engine muffler very soon)

Craig

[R2Home]

When boon docking, I attempt to position the MH so that the gen exhaust is down wind. The other thing I have done is to carry a section exhaust hose that will fit over the outlet on the generator an run it away from the MH. Otherwise we have the same issue at times.

[doc]

Why don't you give Cummins a call and talk with a tech about this? Friend of mine turned down a deal on a coach with a strong (heavy) smelling exhaust. We took it to a local mechanic with the owner's permission and the mechanic seemed to think there was at least one injector going bad. He could not say for sure without some teardown and we did not have permission from the owner to do that.

[Gadget Man]

Originally Posted by doc

Why don't you give Cummins a call and talk with a tech about this?

I have. I have spoken to two different people at Cummins-Onan, and I have received two very different answers. I explained to an Onan tech support rep that my friend’s 2010 diesel generator’s exhaust is much different that my 2005. The exhaust fumes from his genny are not near as strong. The tech told me that newer gensets have a catalyst. When I asked him if an older Onan can be retrofitted with a catalyst, he said he didn’t know and transferred me to an Onan engineer. The engineer told me that newer Onan diesel’s do not have a catalyst. He told me his tech support guy was wrong. He said he knows of no catalyst available for older Onan diesel’s, so I’m back to square one. I for one strongly believe that the newer Onan’s do in fact have a catalyst, based on their exhaust fumes compared to older Onan’s like mine, but I’ve hit a block wall.

Craig

[1ciderdog]

[QUOTEMy wife said it is also impossible to drive behind the RV since I installed the Aero, as the exhaust fumes choke her out. Since I’ve seen no performance gains, I plan on re-installing the factory engine muffler very soon)
Craig[/QUOTE]

Interesting: How close is she driving behind your RV?

[ahicks]

You've installed a new air cleaner recently? I rarely notice the smell of our '97 QD 7500 running, for whatever that's worth.

[Cooperhawk]

Diesel technology has improved a great deal in the last few years.

We had a VW Jedda Diesel that we purchased in 2005. When my wife started it and backed out of the garage it left a heavy smell in the garage for quite some time. In 2012 we purchased a new VW Passat Diesel and this one hardly leaves any smell at all.

The difference is quite dramatic.

[mmorgan]

My 7500 quiet diesel generator barely makes any smell. It's a 2007 model with 1600 hours.


Sent from my iPad using iRV2 - RV Forum

[Gadget Man]

Originally Posted by 1ciderdog

Interesting: How close is she driving behind your RV?

Many car lengths....she followed me to the RV dealer for a slide out repair.

Originally Posted by ahicks

You've installed a new air cleaner recently?

Last November...once a year as the manual calls for.

Craig