How do I adjust the valves on a 96 Blazer, 4.3 V6? When we tighten them to torque specs there is no compression, then when we loosen them and get compression, they loosen up to loose after its been running...any help!, THanks!
first you need the specs on it. then get a feeler guage to adjust the correct clearance from the rocker arm to the valve stem. then tighten the jam nut to torque. a service manual will give you the right info you need and sequence of adjustment
i think the older chevys, you could adjust the valves, but i think now they are self adjustment. what you do is take no:1 rocker and turn the crank, until its all the way down on the low cam and then torque the bolt to specs, do the rest the same way. but if they are adjustable, start your blazer and loosen the rocker until you hear the lifter, then tighten it until it stops, then give it another 1/4 to 1/2 turn more. do the rest of them the same way.
There really is no setting for them, they are hydraulic lifters, tighten the lock nut down til zero lash, then tighten 3/4 turn more. if they are still noisy or loose they probably need to be replaced, if that is the case be sure to check and see if the cam needs to be replaced as well, chances are if the lifters need to be replaced so does the cam...you can run new lifters on an old cam...but Never run used lifters on a new cam. You can go to the Library and look this up in a chiltons or haines manual ... it will tell you the same thing.
THEY AREN'T ADJUSTABLE!!! The problem is the lifters are filled with oil and they won't compress to the point where the valves close all the way. You have to torque them to the proper setting, then turn the engine by hand untill the valves (lifters) have all had time to bleed down in the open position. It's a pain but you have to turn the engine till a few valves are open, then wait a few hours, mark those valves or write them down on a piece of paper, then turn it till some other ones are open, etc etc.. When you put lifters in new there's always some air in them, but when you take the pressure off a used one the spring pushes the plunger inside the lifter up, and it sucks in oil and becomes overprimed. By letting then sit for a while in the open position, the valve spring will push some of the oil out of the lifter, and allow it to reset to the proper adjustment next time the valve closes. Hence the term Hydraulic valve lash adjuster (lifter for short) DON'T WORRY YOU DON'T NEED A CAM OR NEW LIFTERS. THAT HAS HAPPENED TO ME DOZENS OF TIMES.
