Genuine 1991 Pontiac Firebird Lash Adjuster

1991 Pontiac Firebird Parts Questions & Experts Answers

• Q: How can a noisy valve lash adjuster be isolated and what steps should be taken for inspection and reinstallation in four cylinder engine on 1991 Pontiac Firebird?

  A: A noisy valve lash adjuster can only be felt when the engines are idle, by putting a length of hose or tubing near each position valve while you listen at the other end of the tube. A noisy valve lash adjuster is most likely to be caused by wear at the adjuster foot and camshaft lobe, wear, or contamination of the internal parts of the Valvetail. Start by unplugging the rocker arm cover then the intake manifold, as well as the pushrod cover. Relax the nut of the rocker arm and twist the rocker arm from the pushrod to take it out and should in a case whereby many pushrods are removed, they should be placed in an orderly manner so that can be replaced in a rightful manner as they were used. Much like previous models, for later models that have roller adjusters, the pushrod cover studs, the adjuster guide retainer, and the adjuster guide must be removed. If the adjuster cannot be removed easily use a special lash adjuster removal tool, do not use pliers or any other object on outside of adjuster body can damage the adjuster. However, if the adjusters are to be reused a mechanism has to be designed to store them systematically to facilitate reassembly in their precise locations. Every adjuster should be cleaned and dried and should further be checked for any flat spots; if there is any adjuster that is worn concave, scratched or galled the entire set of the adjusters and the camshaft should be replaced. If the adjusters are still serviceable they can be reinstalled in their original locations and coated with moly based grease or engine assembly lube. The remaining installation steps are done in the reverse sequence as used during uninstallation.