1982 240D has smelled quite strongly of diesel /oil for about 2 years. I have had 3 mechanics (2 dealer 1 independent ) check out the fuel system including pulling the, plastic!, fuel tank. No leaks of any kind
have been found. I have washed out the trunk and spare compartment, the spare lid, carpets and all. After 2 days ---it's baaack.. I did not refill the tank during this time.