2 hours for the rear valve cover gasket. if the tech.is the correct one it may ask you too replace the spark plug wire also and since is on the area perform a tune up cause tou be dessapointed after he does tha work you come back.few days later with a missfire, front gasket 1hour. there are wrong if they were working on the car they suppost to advise you. on any other problem and let you deside.if you want the repair or not but that is in the first visit. the 172 dollar bill is question????? they could create that condition.?????? it was like that before' ?? but againg if the engine have high miles or toomany years old well you know what i mean evrything closed to were is repair brakes and some time ind the other side back the engine some people lifted to ease repair they have no choise .and many other things brake. them againg they suppost to warn you on the first repair best answer is from the dealer that you bough the car warranty ??