Are you getting "engine fumes" or Gasoline fumes? The original post says engine so fooling with the gas tank venting isn't going do much to help this if it's engine fumes
It has been hard to nail down- thought it was exhaust- and it was at first, fixed the leak on the exhaust, and now we get just an occasional wiff- which tells me the fuel vent actually may be the culprit. It's worse with the front windows down, better with the rear windows down. some gas fumes smelled, some oil leak smell as well. Very small sign of an oil leak around the valve cover I am fixing this weekend.
