Q: How to service valves, valve seats, and valve guides?
A: Valve job is a task that must be left to professionals because of its intricate nature and specific tools and equipment required in handling the valves, valve seats and valve guides. The head can be removed by a home mechanic who can then disassemble it, clean and inspect it before reassembling it for delivery either to a dealer service department or an automotive machine shop where it will get its actual service work done. This inspection will help the mechanic to understand the condition of the head and valvetrain components so they know what work and new parts are needed when dealing with an automotive machine shop. Then, the dealer service department or automotive machine shop will remove the valves and springs, recondition or replace the valves and valve seats, recondition the valve guides, check and replace the valve springs, rotators, spring retainers and keepers as necessary, replace the valve seals with new ones, reassemble all these components including checking that installed spring height is correct. In case it is warped, cylinder head gasket surface is resurfaced too. After having Valve Job from a professional one would notice that Head comes out like New. On its return to the engine however, it should be cleaned again to remove any metal particles or abrasive grit that may still be remaining from either of two instances; from valve service or head resurfacing operations not yet rinsed off. All oil holes and passages should have compressed air blown through them if available.