The average cost of a valve job is highly dependent on how many valves the car's engine has and what type of engine it is. A valve job for a 4-cylinder engine costs approximately $85 per valve repaired.
The purpose of a valve job is to resurface the poppet valves and their seats, which control the flow of air and fuel to move the pistons. On newer engines (V6 or V8), a valve job can cost up to $125 per valve that needs repairing, with the cost increasing for engines with over 12 valves. Therefore, a total valve job can cost upward of $1000.