Acura 12211-PZ1-004 Valve Stem Seal B (Nok)

Broken valve springs and defective valve stem seals can be replaced without removing the cylinder heads, typically requiring two special tools and a compressed air source. Begin by removing the valve cover and the spark plug from the affected cylinder, or all spark plugs if replacing all valve stem seals. Turn the crankshaft until the piston in the affected cylinder is at top dead center on the compression stroke, starting with cylinder number one and following the firing order sequence. Remove the rocker arms and shafts, then thread an adapter into the spark plug hole and connect an air hose from a compressed air source. Apply compressed air to the cylinder, ensuring the piston does not move unexpectedly, which could cause damage or injury. The air pressure will hold the valves in place, allowing you to stuff shop rags into the cylinder head holes around the valves to prevent parts from falling into the engine. Use a valve spring compressor to compress the spring, then remove the keepers with small needle-nose pliers or a magnet, followed by the spring retainer, shield, valve spring, and valve guide seal. If air pressure fails to hold the valve closed, the valve face or seat may be damaged, necessitating removal of the cylinder head for further repairs. Wrap a rubber band or tape around the top of the valve stem to prevent it from falling into the combustion chamber, then release the air pressure and inspect the valve stem for damage. Rotate the valve in the guide to check for eccentric movement, and ensure it moves freely without binding. Reapply air pressure to retain the valve in the closed position, then remove the tape or rubber band. Lubricate the valve stem with clean engine oil and install a new guide seal, noting that the springs on the valve stem seals are color-coded. Install the spring over the valve with the closely wound coils toward the cylinder head, then position the valve spring retainer and carefully place the keepers in the groove, applying a small dab of grease to hold them in place. Remove the pressure from the spring tool and ensure the keepers are seated, then disconnect the air hose and remove the adapter from the spark plug hole. Finally, reinstall the rocker arm assembly, valve cover, and spark plug(s), reconnecting the wire(s) before starting the engine and checking for oil leaks and unusual sounds from the valve cover area.

Yes, on non-VTEC models, these components can be replaced without removing the cylinder head.