GM S-Series Pick-ups and SUV's 1994-1999 Repair Guide

Valve Lash

Print

ADJUSTMENT



2.2L (VIN 4) Engine

This engine utilizes hydraulic valve lifters which means that a valve adjustment is NOT a regular maintenance item.

4.3L Engine

The 4.3L engines may be equipped with either of 2 rocker arm retaining systems. If your engine utilizes screw-in type rocker arm studs with positive stop shoulders, no valve lash adjustment is necessary or possible. If however, you engine utilizes the pressed-in rocker arm studs, use the following procedure to tighten the rocker arm nuts and properly center the pushrod on the hydraulic lifter:

  1. To prepare the engine for valve adjustment, rotate the crankshaft until the mark on the damper pulley aligns with the 0º mark on the timing plate and the No. 1 cylinder is on the compression stroke. You will know when the No. 1 piston is on it's compression stroke because both the intake and exhaust valves will remain closed as the crankshaft damper mark approaches the timing scale.
  2.  

Another method to tell when the piston is coming up on the compression stroke is by removing the spark plug and placing your thumb over the hole, you will feel the air being forced out of the spark plug hole. Stop turning the crankshaft when the TDC timing mark on the crankshaft pulley is directly aligned with the timing mark pointer or the zero mark on the scale.

The valve arrangement is as follows:



E-I-I-E-I-E (right bank-front-to-rear)
 
E-I-E-I-I-E (left bank-front-to-rear)
 

  1. With the engine on the compression stroke, adjust the exhaust valves of cylinders No. 1, 5 & 6 and the intake valves of cylinders No. 1, 2 & 3 by performing the following procedures:
    1. Back out the adjusting nut until lash can be felt at the pushrod.
    2.  
    3. While rotating the pushrod, turn the adjusting nut inward until all of the lash is removed.
    4.  
    5. When the play has disappeared, turn the adjusting nut inward 1 3 / 4 additional turns.
    6.  

  2.  
  3. Rotate the crankshaft one complete revolution and align the mark on the damper pulley with the 0º mark on the timing plate; the engine is now positioned on the No. 4 firing position. This time the No. 4 cylinder valves remain closed as the timing mark approaches the scale. Adjust the exhaust valves of cylinders No. 2, 3 & 4 and the intake valves of cylinders No. 4, 5 & 6, by performing the following procedures:
    1. Back out the adjusting nut until lash can be felt at the pushrod.
    2.  
    3. While rotating the pushrod, turn the adjusting nut inward until all of the lash is removed.
    4.  
    5. When the play has disappeared, turn the adjusting nut inward 1 3 / 4 additional turn.
    6.  

  4.  
  5. Install the remaining components, then start the engine and check for oil leaks.
  6.  

 
label.common.footer.alt.autozoneLogo