Q. We have a 2005 Class C motorhome on a Ford E-450 chassis with a V-10
gas engine and about 6,000 miles on it. Recently, we have started to get a smell like
rotten eggs or sulfur from the exhaust. You can’t smell it inside when driving, but when
standing outside when the engine is running the smell is strong. What could be the source
and what can I do about it?
A. Almost all gasoline contains some sulfur,
and some brands and batches have more than others. The “rotten eggs” odor is from that
sulfur. You may eliminate the problem by changing to a different brand of gas. If the odor
persists, your fuel mixture may be too rich or the catalytic converter isn’t working right;
however, these malfunctions should set a “check engine” light. Therefore, first switch fuel
brands.
