2001 4-cyl; that would be an F23 just like I have. Valve clearance = valve lash; same thing but I don't know where the word 'lash' comes from.

- Do this with the engine completely cold.

- Remove the valve cover.

- Spin the engine (only forwards) until each cylinder comes to TDC on it's compression stroke. This is when both valves for that cylinder are completely closed.

- The adjuster is a small threaded "bolt"-like thing on each rocker arm. You check the clearance with a feeler gauge between the valve stem & this adjuster. If it needs adjusting, there's a jam nut to release so you can turn the adjuster.

- I don't know what the clearances should be. Probably listed on the emmissions sticker under the hood, but you ought to get yourself a repair manual.

- Turn the engine (forward only) to do the next cylinder.

- Age & heat can make the valve-cover gasket hard; it may not re-seal. Get a new gasket if you want.

- Don't over-tighten the valve-cover bolts. They can break...