I have a 2003 Honda Civic Coupe. Last time I went for an oil change at the dealership, they said they have no history about me doing any valve adjustment and that I should do it and quoted $198 for it. I called around and regular auto shops don't seem to offer this service. My question is do I really need this service done and if I don't do it, what happens?

 

Depends. On mine, for some reason it says to get a valve adjustment done once at like 20,000mi, and then it never needs to be adjusted thereafter.

It couldn't hurt if you trust the shop because it's easy to mess up. If you run with the valves out of spec for too long you could get a burnt valve, but liklihood probably isn't that big. Usually out of spec valve gap will make the engine tick a lot when the gap is too large.

 

If the engine makes excessive tapping / rattling noise especially when cold, it's probably the valve adjustment. The problem is deciding how much noise is "excessive", you won't know that until after adjusting the valves.