The repair of oil on a car’s spark plug threads is an important task that should not be taken lightly. The cost of fixing this issue can differ greatly depending on the location, the skill of the mechanic, and the parts used in the repair. Generally speaking, it will cost around $215 to $261 to complete the job. This includes the parts, which will typically be between $54 and $57, and labor, estimated at around $161 to $203. Investing this money in the repair is a wise decision as it can save you from further problems down the line.