Community Forums

4tfamily · 02-13-2013, 08:16 PM

I've seen numerous posts on here and other forums about a burning rubber smell after towing.

Well, we aren't towing but we had a strong burning rubber smell from our engine (really noticeable in the bedroom, but could even smell it up front) to the point where we pulled over and called CoachNet. They sent out a service guy and he checked it out thoroughly (well, he didn't take apart the bed, to see the engine but got underneath the coach) and guessed that it was just leaving on the exhaust brake too long heated up the exhaust which created the smell.

The exhaust high temp light did come on a few times, so does that sound right?

Anyway, we went along our way, turned off the exhaust brake and haven't smelled it since, but only drove about 30 miles since. Hoping that's the end of it since we're a long way from home.

Oh yeah, we're driving a 2008 Fleetwood Excursion -freightliner chassis cummins engine.

Thanks!

BobGed · 02-13-2013, 08:23 PM

I think what most of us are talking about regarding a burning smell after towing is in the towed vehicle, and not the motor home. If you're getting a burning smell in the motor home, I think it would be important to find the source.

MJFZ · 02-13-2013, 08:44 PM

Could it have been the diesel particulate filter doing a regen? That would heat the surrounding area up and possibly burn off either rubber dust kicked up, or overspray of undercoating.

Mike

Gorlininc · 02-13-2013, 08:45 PM

If your exhaust brake is causing the smell, then there's a problem with your exhaust manifold, I would say.
All your exhaust brake does is restrict your exhaust to cause back pressure in your engine. If your exhaust manifold had a leak, then the hot air is escaping the manifold and heating something up.
This is where I would start. I certainly wouldn't take a trip without my exhaust brake fully working.
Rick

Mike Canter · 02-13-2013, 08:58 PM

Surely the exhaust high temp warning light has a significant meaning especially when it is accompanied by a burning smell. What does your owners manual say about the high temp warning? Leaving the exhaust brake on while driving at a steady speed normally doesn't do anything because it is not activating.

My guess is the guy that Coach Net sent out to you is just a tow truck driver and not a qualified RV mechanic. My recommendation is to take it to a Freightliner service center and have it checked out why you are getting the exhaust high temp light with the burning smell.

4tfamily · 02-14-2013, 05:23 AM

Quote:

Originally Posted by Mike Canter

What does your owners manual say about the high temp warning?

From the owner's manual:
The high exhaust system temperature lamp indicates, when illuminated, that exhaust temps are high due to regeneration of the after treatment diesel particulate filter. The lamp could illuminate during normal engine operation or during stationary regeneration.
NOTE: The OEM determines whether or not the High Exhaust System Temp is installed on the vehicle. The OEM also specifies the temperatures, vehicle speeds, and other conditions at which the lamp illumnates. Refer to the OEM manual for additional info. regarding this lamp.

When the lamp is illuminated, the exhaust gas temp could reach 1500*F, which is enough to ignite or melt common materials, and to burn people.

NOTE: The HEST lamp does not signify the need for any kind of vehicle or engine service; it merely alerts the vehicle operator to high exhaust temperatures. It will be common for the HEST lamp to illuminate on and off during normal vehicle operation as the engine completes regeneration.

Obviously, we checked to see if there was anything that could be burning near the exhaust...nothing. Not sure if the two things are related. I will say that some city driving was done with the exhaust brake on, newbie driver error....but what was heating up so much to cause the smell? The service guy said it could possibly be the sleeve that surrounds the exhaust outlet. Does that sound reasonable?

Thanks!

WesinRockies · 02-14-2013, 05:31 AM

Quote:

Originally Posted by MJFZ

Could it have been the diesel particulate filter doing a regen? That would heat the surrounding area up and possibly burn off either rubber dust kicked up, or overspray of undercoating.

Mike

Mine did just that, rubber dust burned off

4tfamily · 02-14-2013, 05:43 AM

Quote:

Originally Posted by WesinRockies

Mine did just that, rubber dust burned off

So did you smell that smell?

Tony Lee · 02-14-2013, 07:54 AM

Regardless of the cause within the engine compartment, there should never be a smell inside the living space.

I would be taking the bed apart (no hinged lid???) to make sure exhaust gases aren't being directed up at the bed structure and overheating something

4tfamily · 02-14-2013, 04:50 PM

Well, we drove 500 miles today and no smell what-so-ever. Of course we were sniffing constantly. I'm hoping that it was in fact the diesel particulate doing a regen and there was some rubber dust on there.
Anyone know how often the regen happens?
And the bed is hinged but he said he'd have to take off the frame as it was blocking the hatch.

Mike Canter · 02-14-2013, 04:57 PM

Kevin, in that 500 miles did you have an exhaust hot warning light? It could be you will only get this smell when you get the exhaust hot warning light. You need to go to a Freightliner dealer and have it checked as to why you had the warning and why you had the smell associated with it.

WesinRockies · 02-15-2013, 06:56 AM

Quote:

Originally Posted by 4tfamily

So did you smell that smell?

Yes I did, more so outside but some inside, I have a rear bath and I believe it came in though the window as it was not latched, I have now almost 39000 miles and when I got the coach it had 32000 miles, it regen at around 36000 or so. First and only time it has. I called a shop the day that it happened and he thought maybe it was rubber dust as it has been so dry up until snow happened.

Mike Canter · 02-15-2013, 07:01 AM

Not sure I buy the rubber dust. Everyone with that type system would be smelling it and complaining. If so Freightliner would have a Technical Bullitin on the subject.

So why are you smelling it now??????

WesinRockies · 02-15-2013, 07:45 AM

When mine regens again and if I smell it again, I am going to take it in to a shop for peace of mind. I looked all around the exhaust and engine compartment for something melting or rubber that got hot, couldn't find anything, I used a flashlight and mirror to inspect it, and found nothing.