Cost to have vaqlve cover gasket replaced on 1999 Toyota Avalon

A gas station mechanic mentioned that the Avalon 1999 valve cover gaskets are leaking. He estimated 4 hours of time. Is this reasonable. I have known him to take short cuts. He wants me to leave the car with him and he does not want me to be around while he does repair work. Is that reasonable.

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1 answer
That engine has two valve cover gaskets, the front one is easy to replace the rear one is more difficult. It usually takes about a little over three hours at a lot of repair shops to replace but he may be adding time to check the valve clearances which is advisable one the valve cover is off. If the valves do need to be adjusted they are shim adjusted.