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1989 F350 V8-446 7.3 disel engine

frist question; is the oil on this type of truck suppose to be black and second question is where is the antifreeze coming from if it not coming from the radiator or hoses that is leaking underneath the truck

Diesel engines turn oil black in a very short time. The coolant leak could be from where the injector pump mounts to the engine.


  1. It is OK. It doesn’t take long for diesel engines to turn fresh oil black; that is normal.
  2. On a truck this old, you need to take a look and see what is leaking. Could be freeze plugs or other items.

I cant go there. too vague a question ,a smart a#2 would say look up from where it hit the ground.(but not ME)

yes the oil soots up fast.NORMAL.


Yes, black oil means the oil is clean out dirt from the engine’s interior. For the antifreeze, how much are you losing? Could be a head gasket,but that’s not real likely with a diesel. Could be a pinhole leak, that only manifests itself when the hoses get good and warm. Also the 7.3L is 444 cubic inches in displacement.