answer:Talk to a mechanic (have him look at the car) to give you a realistic estimate of what is wrong and what needs to be repaired. I thought that $600 sounded like a lot of money for an oil pump replacement, but apparently that’s not such a bad estimate. So that would cover the cost of the oil pump replacement, but as you have already guessed, if it went out and people continued to drive the vehicle, then there may be significant engine damage, too. But no one can determine that without seeing the vehicle.