Exhaust Residue ??

Don't know what caused it but I have seen a few motor homes where this area and especially areas around the bedroom access to the engine was coated with what I was sure was soot from diesel exhaust. Need to make sure to identify what is going on. No matter what it ain't good.

In the rear engine motorhomes we have had/have there is a lot of caulking where the rear of the inner body butts against the outer shell. You might want to look around the rear radiator and see if perhaps there is a gap there letting in some exhaust gas. Just a thought.

Ed Headington

And not all black mold is dangerous

Make sure you do not have an exhaust manifold leak or crack. This will allow soot into the engine compartmant where it can then come into the rear of the coach

Not all black spots are mold. Mold is a fungus like mushrooms, although smaller and because of that it will have a texture and generally feel slimy to touch. It will generally have a musty odor.

Yes... Rear Bedroom Back Wall in Rear Bedroom Closet..One of three
Closets... Rear Driver Side is Padded Vinyl where black soot or mold is evident,
Middle is Cedar Lined..No Residue there.. Rear passenger Side has TV Slideout and what
I could see with a flashlight was all good.. Going back on Monday and see what I can wipe out with a cloth to get a better idea what it is. ? It is more concentrated at the corners but it does have a lot dusting on the walls. ? Or first DP so would the residue be obvious if it was
D EXHAST

Not an expert, but believe mold grows in colonies and generally appears as round "dots" and might look a little "furry"?

Id the closet above the exhaust system?

Well that is a thought.... This DP had been taken real good care, 21000 miles which seemed like low miles for a 2005... Dealer owner and salesman are good friends so trust is solid but it was missed on prep by a lazy cleaner I suppose... The odd part was that it was hard to get of my finger after I rubbed on it to see what it was so, ASSuming lol it was exhaust, Mold had never even came into my head but I bet you are correct sir.... Anyway to check that it is mold from being parked for a while and not DExhast?? Or maybe as well the proper cleaner to use on the liner? ? Thanks for the help and hope you are right. I was worried it may be an exhaust leak

Sounds more like it could be black mold instead of exhaust.