Valve spring failure and valve stem seals can be repaired by replacing them without the removal of the
Cylinder Head; it normally requires two special tools and compressed air. Start with the elimination of a proper valve cover, the rocker arm assemblies then spark plugs from that certain head. Place the car's piston of the malfunctioning cylinder at the topmost position of the compression stroke; begin with cylinder number one and crank on one cylinder to the other, following the firing order sequence of the engine. Insert an adapter into the spark plug hole and attach an air hose to compressed air supply. Use compressed air to blow out debris within the cylinder and use clean shop rags to plug the cylinder head holes over the valves and under them with a view of avoiding loss of small parts and tools inside the engine. This is done using a valve spring compressor tool to compress the spring then quickly remove the keepers applying the use of small needle-nose pliers or a magnet to pick the retainers and the valve spring. Take off the valve guide seal and the spring seat lifting because if air pressure is not strong enough to keep the valve closed the valve face and or seat can be damaged and requires the removal of the cylinder head for further repair works. Tightly coil a rubber band or metallic tape around the top of the valve stem so that it doesn't drop in the combustion chamber then minimize air pressure and assess the condition of the valve stem. Turn the valve in the guide and try to move it along an elliptical race; if it sticks the head will have to be pulled out and re-machined. Raise the valve stem upward in order to shut the valve, use air pressure to maintain the latter state, and then take off the tape/rubber band. Put the valve spring seat and lubricate the valve stem with clean engine oil, and then put the new valve guide seal and drove it into place with a deep socket. Place the spring over the valve, put the valve spring retainer in position, compress the spring and put the keepers into the groove and if they do not sit into the groove securely apply small amount of grease. Take the pressure off the spring tool, make sure the keepers are in place, shut off the air hose and quickly, but carefully, unscrew the adapter from the spark plug hole. Do the same for any other defective valves, set in the rocker arm assemblies, spark plug, and connect the wire(s) and then put back the valve cover. Last of all turn on the ignition and the engine to look at the oil streaks and odd noises from the valve cover engine area.