GM 17120090
Valve Lifters

Lift off the lower Intake Manifold, then take off the valve rocker arms and valve push rods to replace the valve lifters. Next, remove the valve lifters and clean any varnish out of valve lifter bores with a cleaning solvent and ship towel. Check on the valve lifter bores for serious wear and scoring. In case it is found, the engine block needs to be changed. Also, inspect the Camshaft for wear or damage, and in case the wear is in question, take off the Camshaft to fully inspect it. Inspect and clean the valve lifters and the valve Pushrod guide before install. It should be noted that there should be a slight ticking noise after starting the engine for new lifters; this however can be done away with by say an increase in revs of the engine so as to raise the pressure of the oil. Finally, install valves lifters, then rock arms and push rods, and then the lower Intake Manifold.

Begin Lash Adjuster replacement by removing the lower Intake Manifold. Start by removing the valve rocker arms alongside the valve pushrods after which you can proceed with the lash adjusters. Using cleaning solvent and shop towels to remove varnish from Lash Adjuster bores leads to bore inspection for excessive wear or scoring and possibly resulting in engine block replacement. Inspect the Camshaft for wear and damage while checking for any damage. Before any judgment on the Camshaft wear's ambiguity remove that component for investigation. Check and clean both the lash adjusters and valve Pushrod guide after inspection. The new adjusters will produce a minimal ticking noise during your vehicle's first startup. Noise should disappear when you increase engine rpms just enough to boost oil pressure. After installing the lash adjusters you should put in the valve rocker arms and pushrods then reinstall the lower Intake Manifold.

In order to replace the lash adjusters, remove the lower Intake Manifold. Next, you will need to remove the valve rocker arms, valve pushrods and of course, the lash adjusters. Use a cleaning solvent and a shop towel to remove any varnish from the Lash Adjuster bores, and check the bores to determine if they are excessively worn or scored and change the engine block if necessary. Examine the Camshaft for wear or damage. If the wear is questionable, remove the Camshaft for inspection. Check and clean the lash adjusters together with the valve Pushrod guide. During the installation of the new adjusters, please note that it might make some minor ticking noise when the engine starts for the very first time, which should fade out as the engine rpms are juiced a little as this causes oil pressure to rise. Go ahead and install the lash adjusters, then the valve rocker arms and pushrods respectively, and reinstall the lower Intake Manifold.

Align the flat area on the top of the lifter with the flat area in the lifter guide bore, and push the lifter completely into the guide bore.

Use the Valve Lifter Remover (J 3049-A) to extract them.

Apply lubricant GM P/N 12345501 or equivalent to the valve lifter rollers.

Use the Valve Lifter Remover (J 3049-A) to assist in their removal.

The engine block must be replaced.

Remove the valve lifter guide bolts.

Remove the intake manifold and the valve push rods, ensuring that the valve lifters and guides are installed in their original locations.

Check for excessive wear, cracks, or damage.

Remove the valve push rods, ensuring that the valve lifters and guides are installed in their original locations.

Ensure they are installed in their original locations.

Increasing the engine RPM slightly to raise oil pressure should eliminate the noise.