My 1999 Ford Mustang V6 3.8L has oil in the radiator and is missing and jerking when driving.

If you do not have serious pressure build up in the coolant system and just oil it is most likely a crack in the head or blown gasket between the water jacket and the engine oil. Usually this will result in more water or coolant in the oil than oil in the coolant, just depends on where the actual problem is located in the engine. With the bad miss associated with this problem I would start with a compression check on all cylinders, I would say that you are looking at a head gasket problem at best and a crack in the engine block at worst.

I think inspector is got the idea. Is it a automatic? Some times the rad. goes bad, you get automatic fluid in the rad. Is it black like engine oil? If dark the insp. might have it.

In case anyone missed it, this question is over a year old.

If it is the engine that is missing, it is doubtful that the radiator is leaching ATF into the coolant.

It is more likely a breach of the head gasket from the oil pump side of the system, which can pump a small amount of oil into the coolant.

In addition, the missing is likely caused by coolant entering the combustion chamber.

This answer was edited by the_mekanic 159 days ago.

Reason: add

Yes i think the inspector i to think its a crack in the head or blown gasket between the water jacket and the engine oil. i mean thats what it sonds like to me that would be y you are getting oil in the water as well as the other way around to check it out

Either way, The car had a recall for heads. Should be a free fix.
I put this in for future, Incase it is found in a search.