Good morning everyone. Here is some information about how easy motorhomes can catch fire while driving down the road. A party recently limped in to Quartzsite, AZ with a Monaco motorhome, stating that something was wrong with engine. Note: they had been at service shop about 300 miles away but the mechanic could not find anything wrong.
I started troubleshooting the problem and could not see anything out of place except that there was a smell like burnt rubber or plastic. Note that as we get older for some reason we just cannot fit under a motorhome. So I decided to move Motorhome on our oil changing pit to get a better idea what problem could be.
The engine is an ISC Cummins and equipped with exhaust brake. The bracket supporting the exhaust pipe had broken at the clamp along with the special clamp that connects the exhaust pipe to the Pac brake. This allowed the exhaust pipe to drop down about 4 inches, resulting in the hot exhaust from engine applying heat to the underside material including wires and lines, etc. (see photos). The extreme heat melted the bottom of the floor under a storage compartment allowing the gas to enter the storage compartment itself. The size of melted opening was about 18 inches long and 12 inches wide. The only thing we can figure out is the storage compartment with its seals on doors and packed tightly did not supply enough oxygen to allow the extreme heat to break out in flames.
Look closely the pictures.
This is the third motorhome where fire damage occurred but went unchecked or unnoticed other than smell. I posted the info about the fire danger in Roy and Vicky Warren’s coach in October, due to CAC cooler piping.
We all need to understand age can cause problem with our coaches (and us). The many miles can cause problems that never happened back in the early days of owning a motorhome but are starting to stand out. Inspection in the engine compartment is extremely important at this point!
Dave Atherton Retired Cat Mechanic
