1996 Mustang GT Oil in cooling system
I have a 96 Mustang GT 4.6 stock with 143,000 miles. I noticed lately there's oil in my cooling system inside the overflow tank. It shows as a dark color in the coolant and beige thick substance on the cap. However, the vehicle doesn't overheat as of yet and the motor oil in the block is fine- color is normal with no sign of coolant. It appears the oil in the coolant may be the sign of a blown head gasket but I would like to make sure before I do a head job. Are there other factors that could cause this?
Additionally, if any of you have any tips or advice on how easy is it to pull off the heads and replace the head gaskets off this particular engine, please let me know. Hopefully, the heads aren't damaged. I've never changed heads before on an engine so any help would be greatly appreciated. The only work I did myself on this car is replace the intake manifold.