by chance, are you talking about a dodge or Jeep product with a Magnum engine from the mid 90's? I have two trucks (a 95 Jeep GC 5.2 and a 95 Dakota 3.9 ) that both have approx 1/2" of what looks like black paint on the very end of the dipstick. I'm not the original owner, but I have to believe that, in my case, this is done at the factory and not a stain.