Table of Contents
What is sticking valve?
Sticking valves are caused by excessive deposits of lead or contaminants in the valve guide or by valve seat wear which allows the fatter bottom part of the stem to travel farther than it is supposed to up into the bottom of the guide when the valve is closing—the latter is especially true on the small Continentals.
How do you free up a sticking valve?
Let the penetrating oil soak for several minutes. Gently tap on the top of the valve springs with a small hammer. Tapping the tops of the valve springs with the hammer will sometimes free up the valve stem shaft so that it can move properly. Replace the valve covers and listen for any clicking or clacking noises.
What causes engine valves to stick?
Sticking valves are almost always caused by resin deposits left by oil caught in between the valve guide and valve. These deposits are the result of impurities in the oil overheating in the space between the valves and guides.
How do you inspect an engine valve?
Visually inspect each valve for signs of burning, warping, and excessive wear on the face, stem, and tip. If found, replace the valves with new ones. Visually inspect each valve seat for signs of burning, leaks, or excessive wear. If found, the seat must be machined or replaced.
Will a stuck valve cause low compression?
There could be a stuck, burnt or leaking valve. If the compression is low or zero on two adjacent cylinders; it would indicate a leaking gasket. There is a weak sealing surface at the head to block mounting area; which basically means a bad head gasket.
How do you inspect and measure valves and valve stems?
Lightly oil the valve stem and insert it into the cylinder head. Position the dial indicator against the valve stem near the tip and zero the gauge. Grasp the valve stem and wiggle towards and away from the dial indicator and observe the readings.