Valve taps often occur as a result of a misalignment in the fitting they are in, or a worn out valve seat. In many cases, a new valve spring and cam adjustment will fix the problem, but if it the result of a worn out valve seat, it will have to be machined.
Stop Valve Key
An engine "knock" will become more pronounced when engine is labored (climbing a hill) Valve noise will remain the same under stress
An "engine knock" will be more noticable when engine is labored (climbing a hill etc.) Valve noise will remain constant
Spray wd40 or equal and tap valve "gently" with a hammer while "gently" appling turn pressure on valve.
you probably have a sticking valve lifter.
Reseal or replace the valve.
Sure, an engine is not a motor but its a common term for engine. That diagnosis is correct! I've found... The Mega Power Valve Treatment is a different way to end that dreadful tap tap tapping. Different because you get a free engine motor tune up with it! Online about it.
There is a shutoff valve on the cold pipe going into the H/W tank, if you close it no water will come out of the tank. There should also be a shutoff valve on the wall below each faucet/tap.
The "curb stop" is the valve that is on the service from the main into your house. i.e. The 8" main in the street has a saddle tap with your 3/4" service line on it. Within 8 ft of the connection between your service and the main is your curb stop. The curb stop is a valve buried underground. In order to open/close the valve a curb box is placed over the valve. It is essentially a metal tube that lets you open and close the curb stop.
tap valve
Check the egr valve.
1998.5, or any 24 valve engine.