Subject: valve tap
Question: My car has a valve tap and i was wondering if i could save money by fixing it myself. i want to know how involved this project could get and or how much it would cost to take it somewhere to replace a valve.
Answer: Anthony,
Not knowing what kind of car (year, make, model) you have, its hard to give you an idea how involved the job is.

If you have a relatively simple engine (1.8L, SOHC), you could perform the job yourself if you have some mechanical knowledge and a good service manual; Chiltons or Haynes.

If you have a more complex engine (2.0L, DOHC, Turbo), you should have very good knowledge of car repair, a lot of time, and a genuine factory service manual for your exact car.

Taking your car to a service garage can be costly if you have a complex engine as mentioned above. It's a very time consuming job and the parts are not cheap either. You'll want a qualified technician that has experience with your type of engine. Odds are, if one valve is bad, the others are either bad or going bad.
Hope this was helpful. Good luck!