I have loud valve noise, all the time. What's the problem? Check your oil level!
If your oil level is OK, you probably have one or two broken oil pressure valves. There is one oil pressure valve in each head that
can be accessed by removing the valve cover. These valves keep oil going to the hydraulic lifters at a constant pressure. In the event
of a failure of one of these valves, all of the lifters on that side of the engine may have low or no oil pressure. This is a
Bad Thing which should be taken care of quickly. If one of these valves has suffered a catastrophic failure, you should probably pick
up new hydraulic lifters when replacing the valves -- the lifters are cheap and you will probably have six bad ones.