A common clue is that a noisy valve lash adjuster can be detected during the periods when the engine is idle by using a mechanic's stethoscope or a piece of hose to listen close to each of the valve locations. However, the valve cover can be removed and by holding each of the valve spring retainers while the engine is running, one can easily discover defects by the shock that is felt at each retainer. Some of the causes of noisy valve lash adjusters are dirt in valve lash adjusters, and inadequate oil flow, viscosity, or pressure; hence one should first check the oil for contamination with fuel, its level, condition and viscosity before coming to any conclusion. Lash adjusters are removed by first removing the intake manifold and the valve cover(s) and then the
Rocker Arms, the
Pushrods and finally the heads of the cylinder from the engine block. Bolts are used through the retaining plate to secure it, to reach the lash adjusters, the alignment yoke should be lifted off. The lash adjusters can be pulled out with a special tool, a small magnet or by hand, if the varnish is not thick, but should not be removed with pliers unless they are planned to be replaced, as this might harm them. Pack the lash adjusters in a box that has labels for the lash adjusters so that they would be replaced in their respective place. For examination, first, clean the lash adjusters having a solvent, and then look for scuffing, score marks or uneven wear on the lash adjuster walls or pushrod seats, lash adjuster bores in the block. Each lash adjuster's roller should be rolled and rocking action looked for; the lash adjuster's roller should be free and not flat or pitted; rollers on cam journals should also be examined for any irregular wear. Old lash adjusters that have been used should be reinserted to the initial bore which they were removed from; new lash adjusters should be dipped in oil to eliminate trapped air; all of the lash adjusters should be covered with moly-base grease or engine assembly lube. As with removal the installation procedure is reversed and the bolts of the retaining plate tightened to the correct torque the engine is then run to check for signs of oil leaking.