Oil in coolant or… Coolant in oil???

pretty sure not the same thing?

I have OIL in my expansion tank with the fluid level in the tank low.

 

When the engine is running, oil pressure is higher than the pressure in the cooling system, so oil tends to go to into the cooling system. If your coolant level is low and you have oil in the expansion tank, I'm afraid that might be a failed head gasket. The reason is your engine may be consuming the coolant through the combustion chamber.

Any overheating issues?

 

not yet. Once I found the oil in coolant I took the car off the road until I can do a thorough diagnostic. Thanks for the heads up on head gasket.