I just bought a car and when checking the fluids took off the radiator cap it was full of oil and no coolant I need to know if a new radiator and flush will save the motor?

It all depends on why there is oil in the radiator. If there is a crack in the block or the head, flushing won't do anything for you.

Have you checked the oil? What did it look like? How was the level?

I bought a car with the same problem and installed new radiator and coolant and oil came back in. Had a mechanic check it and he said it was most likely a cracked block and it would be approx $2000 to fix. I resold the car within 2 weeks.

No one here without complete check of your car can tell you. How the oil got into the water is the issue.