Free 7 Day Trial RV GPS App RV Trip Planner Campground Reviews RV Maintenance Free 7 Day Trial ×
RV Trip Planning Discussions

Go Back   iRV2 Forums > MOTORHOME FORUMS > Class A Motorhome Discussions
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
Thread Tools Search this Thread Display Modes
Old 06-23-2021, 03:00 AM   #1
Junior Member
Join Date: Nov 2019
Posts: 1
Diesel Dust

I just made my 3rd trip in my 2021 Tiffin 38 RED 340 Cummins. It was 150 mi to the dealer for a couple of simple warranty issues. When I got there and got ready to unhook the toad I couldnít believe it.
The backside of the coach had diesel soot all over it and my white Buick was just covered in soot. I literally had to wash the window before I could drive it and the front end was totally gray/black..

Has anyone seen this issue on a brand new coach(2700mi) and do you think itís safe to drive it to my freight liner shop which is another 150 miles?
Of course the dealership said they had no idea....
Twhitak is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free! RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 06-23-2021, 04:04 AM   #2
Senior Member
Dunrollin's Avatar

Damon Owners Club
Join Date: Sep 2020
Location: FL
Posts: 176
As you already know that is not usual. Soot is from unburned or not completely burned fuel, so you may have a code stored. Can you read the engine's codes? It sounds to me like one injector is over fueling.

Hope you get it solved. Frieghtliner is the place to start.
2002 Damon Escaper 3126E Caterpillar, Allison 6 speed.
Dunrollin is online now   Reply With Quote
Old 06-23-2021, 05:29 AM   #3
Senior Member
Mr.Mark's Avatar
Join Date: Jun 2010
Location: CA and TN
Posts: 2,670
What I'm perplexed about is that you have a particulate filter along with the DEF system. There should be no soot whatsoever come from your exhaust.

I'm wondering if it is just heavy road dusk. I've never had the dust to the extent that you describe but I always get 'road dust' every time I drive my regular cars, etc. Since I have several white cars, I can run my finger along the back fender/trunk/bumper and have black dust on my finger.

Roads have this dust from tire rubber etc. I just don't think its from your diesel although it does seem excessive as 'road dust' from my experience. If it was your diesel engine, you should have RED lights all over the dash indicating a problem (I would think).

Do you think it might be oil?

Looking forward to seeing what you find out.

Safe travels,
2021.5 Pleasure Way Plateau FL Class-B Sprinter
2017 Lincoln MKX, AWD, 2.7 V6 335 hp twin turbo
(Sold)2015 Prevost Liberty Coach,(Sold)2008 Monaco Dynasty
Mr.Mark is offline   Reply With Quote
Old 06-23-2021, 06:34 AM   #4
Senior Member
153stars's Avatar
Join Date: Mar 2019
Location: Braidwood Il.
Posts: 3,788
I agree with road grime. How's the tail pipe if flaking off an 1/8 thick maybe an issue. Reminds me of when my 2yr grandson found my tail pipe... had soot all over his face like a chimney sweep and I kept finding things in there, bug spray , pop cans, sippy cup, sunscreen ect.
95 Monaco Crown Royale
M11 400hp, 4060 trans.
Aquahot, Generac Guardian7.5k
153stars is offline   Reply With Quote
Old 06-23-2021, 06:36 AM   #5
Senior Member
Join Date: Mar 2017
Posts: 223
I had a similar problem with my pre emission 330 Cat. But i noticed I also had low turbo boost psi. I replaced the leaky CAC and turbo boost is up to specs and the dust is all but gone now.
desertdd is offline   Reply With Quote
Old 06-23-2021, 08:31 AM   #6
Senior Member
MN_Traveler's Avatar
Join Date: Apr 2012
Location: Minneapolis, MN
Posts: 830
Agreed that with a def system there just should be no dust. Try to verify heather it is just road grime (my toad definitely gets dusty/dirty). If you still think it is from your engine, have freightliner take a look.
- 2017 Newmar London Aire -
MN_Traveler is offline   Reply With Quote
Old 06-23-2021, 08:31 AM   #7
Senior Member
Join Date: Dec 2013
Location: Lake Havasu City, AZ & Plover, WI
Posts: 4,737
Check the exhaust pipe. If the dust is coming from the engine, the inside of the tail pipe will be black and powdery. It should also be more pronounced on the exhaust side. If it is uniform all over the toad and back of the coach, I would suspect road dust. After 77,000 miles, my tail pipe is still clean to the touch.
2013 43 QGP Allegro Bus
2013 Avalanche
CJ7 Rock Crawler
Crasher is online now   Reply With Quote
Old 06-23-2021, 11:34 AM   #8
"Formerly Diplomat Don"
Dutch Star Don's Avatar
Newmar Owners Club
Join Date: Apr 2005
Location: Moorpark, Ca.
Posts: 18,514
Crasher has it right, your tailpipe should be clean enough to eat off of.....obviously easy to check. If it's black, you have an issue.

Keep in mind that the rear of your coach is a BIG vacuum cleaner. It sucks up air and dirt, from under the coach and blows it out the back through the radiator. If you've ever stood back there with the engine running, it can part your hair.

That's why it's so important to flush/rinse the radiator and charge air cooler once a year.
Don & Mary
2019 Newmar Dutch Star 4018 (Freightliner)
2019 Ford Raptor
Dutch Star Don is offline   Reply With Quote
Old 06-23-2021, 02:17 PM   #9
Senior Member
Join Date: Mar 2019
Location: Lansing MI
Posts: 1,930
Gray black could be road dust, I'm thinking that exhaust soot would be pure black and oily. I do agree with checking the exhaust pipe. It could also be an oil leak, they make a mess out of the back of any vehicle and whatever it's towing. Without looking at it or a picture all we can do here is guess. Good luck.
An Old Fisherman
2017 Nexus Ghost 36DS, 2004 Ford F150 Long Bed
2007 Harley-Davidson Ultra Classic
arcaguy is offline   Reply With Quote
Old 06-23-2021, 06:12 PM   #10
Senior Member
Join Date: May 2020
Posts: 438
Agree with the above poster that it could be an oil leak if you have ruled out road grime. It doesn't take much oil to make a real mess.

Saw it once from the pumpkin on a Chevy Suburban. The gear oil leaked out and all over an old Land Cruiser I was towing. You would be amazed how much of that gear oil made its way onto the Cruiser. I mean there isn't all that much gear oil in a pumpkin.
2007 Newmar Kountry Star 8.9 liter cummins
2019 F250 Toad
Blue OX
Keith55 is offline   Reply With Quote


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Determination of Dust Ingestion on Diesel Engines spike45 Cummins Engines 19 05-12-2014 09:05 AM
Dust wahlfamily Full-Timers 2 01-24-2009 03:54 PM
The first dust storm for 07 WaveMaker Southwest Region 4 07-19-2007 01:17 PM
Dust collection on rear cap jimandsue60 Winnebago Industries Owner's Forum 12 07-06-2006 05:25 AM
Another WW Stock Item Bites The Dust 56Nomad Toy Haulers Discussion 23 03-13-2006 06:22 PM

» Featured Campgrounds

Reviews provided by

All times are GMT -6. The time now is 06:37 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.