can someone help on how to tighten valves on a 1987 s10 blazer its a 2.5L 4cyl.... plz

 

Because the rocker arm fasteners are secured and torqued, valve lash is NOT adjustable on the 2.5L engine. If a valve train problem is suspected, check that the rocker arm bolts are tightened to 22 ft. lbs. (30 Nm). Be sure to only tighten the rocker arm bolts when the hydraulic lifter for that rocker arm is on the base circle of the camshaft and NOT when it is held upward on the lobe. When valve lash falls out of specification (valve tap is heard), replace the rocker arm, pushrod and hydraulic lifter on the offending cylinder.