Diesel Exhaust Fumes In Coach

[BOBODELL56]

I recently purchased a 2015 Fleetwood Discovery 37R.

On approximately four occasions, my wife and I have smelled what seems like diesel exhaust fumes inside the coach. The strange part about this is that it is while we are traveling down the interstate. It usually lasts between 10 and 20 minutes.

Could it be happening during the regeneration process that the newer motors with DEF go through periodically?

By the way, it does not matter if the generator is on or off.

Any ideas out there?

[wolfe10]

Bob,

Welcome to the FMCA Forum.

Any correlation between the smell and inside venting (i.e. anything that creates a vacuum inside). So, dash HVAC on recirculate, any roof vent open, any window open?

[blakeloke]

Bob,

I'd also check your exhaust system to see if you detect evidence of a leak. If you have a leak, it'll be noticeable in the form of black soot. I know your coach is new but the possibility exists that there may a small leak around a flange or hose clamp. if so, exhaust could be venting inside your coach from the rear.

You also might check for soot around any floor access panels to the engine compartment.

Blake

[BOBODELL56]

Thank you all for your posts. As to the recirculation possibility, I am reasonably sure that the HVAC was on recirculate, because that is how I set in in my other vehicles. I will check for a leak as well. It does seem very strange that it only happens occasionally. It is not a constant problem. Thanks again for your ideas.

[five]

We had a similar issue on a past MH...a slide was not sealing tightly.

[campcop]

You don't mention what chassis or engine you have but if it's a Freightliner with a Cummins 8.9, chances are you are getting the fumes when the engine goes into regen mode. When that happens, a large amount of fuel is dumped and exhaust temps and pressure rise to clean out the DPF.

We have experienced the same thing and so have many Phaeton owners. Some have been lucky to find a leak in the exhaust. I had Freightliner check my exhaust and all the fittings were tightened but I still get the exhaust smell on occasion.

I just found an open wire chase under the MH, right next to the engine compartment that leads to the electrical panel in our back closet, I will be attempting to seal this in the next few weeks.

[BOBODELL56]

To Campcop:

Your post seems to me to be the most likely culprit. That the smell happens during region also seemed to me to be the most likely reason. I will have Freightliner check this out when I take it in for replacement of a defective DEF gauge (on the tank). Thanks to everyone for your informative posts.

[FreightLinerFever]

You are getting air from outside. I had a 2008 FLEETWOOD, SAME ISSUE, FOUND THE TRAP DOOR IN THE CLOSET WAS NOT PROPERLY SEATED AND I WAS GETTING EXHAUST IN THROUGH THERE.

[campcop]

You are getting air from outside. I had a 2008 FLEETWOOD, SAME ISSUE, FOUND THE TRAP DOOR IN THE CLOSET WAS NOT PROPERLY SEATED AND I WAS GETTING EXHAUST IN THROUGH THERE.

On the newer diesels, between the DEF and PDF, there is virtually no diesel exhaust smell from the tailpipe. Any fumes come before the DPF, usually during regen...some have found loose clamps or a cracked flex pipe.

[manholt]

I get it on regen, about 5 min and then the smell goes away even though the clean out lasts another 10 min. Nice part is, I know what it is and I don't have to pull off the road and stop...I still drive down the highway. Some units you must stop and wait. Exhaust pipes go over 1400 degrees during process!

As campcop said, DEF engines don't have that issue!

Carl