I have gas fumes in the trunk. There are no leaks to my knowledge. Tank appears to be under pressure based on gas cap removal. A mechanic told me if could be a rollover vent valve that is stuck?? I just went on atrip to the mountains (4000FT) and the mechanic said that the altitude could effect the operation the valve due to it's age. I have a 89 420SEL. Any comments--the fumes are killing me.
1989 420 SEL