DO NOT CRANK OR TURN THE ENGINE OVER ANYMORE, until you change the oil and filter.
99% of engines that have been run on "chocholate milk" "cafe latte", "milkshake" etc, which is a mix of oil and coolant do not last much longer. Of course you will hear of people who will say its perfectly fine to just change the oil and drive it but I respectfully say "nay" to that.
Change the engine oil and filter, and when you change the filter see if the big center bolt on the filter housing spin-on part is loose. Also, if you can pressurize the cooling system with the engine off, look in the oil cooler and see if its leaking in there.
Then, don't drive the car, but you can now safely crank it over a few times for diagnostic purposes.
Leak down, compression test, pressurize the coolant and look/listen for leaks.