Whenever you're dealing with a car, there is always a chance for something to go wrong. Oil leaks are inevitable in any car, especially as you get more miles on your engine. But It depends on the car and the severity of the leak. The average cost to fix an oil leak includes: - A small oil leak may cost $300-$500. - A medium-sized leak may cost $1,000-$1,500. - A severe leak may cost $2,000-$3,000. Here's my affordable small leak fix hack.