Questions and Answers
Rotten Egg Smell
Q. Hi Vincent, I would like to know if you can tell me what would cause my exhaust to sometimes smell like rotten eggs? It doesn't do it all of the time just occasionally. My vehicle is a 1993 Mercury Villager.
Thanks for any answers you can give me,
WilliamA. That "rotten egg" smell is sulphur dioxide. Sulphur dioxide is formed when the sulphur in the fuel is burned and combines with oxygen. You might remember the smell from high school when you passed the chemistry labs.
The smell usually occurs if you are using fuel with a high sulphur content, the fuel mixture is too rich or if you have driven the car hard for a while.
If it happens occasionally, then it's nothing to worry about. If it is a constant thing, however, it might be an indication of an engine problem of poor quality fuel. You can try changing brands of gas to see if it goes away.
Additional Information provided courtesy of ALLDATA
