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Hello again Vette-strs :D
After adjusting my valves a couple of dozen ways.. I still have a very distinct clacking noise comming from somewhere in the valve train. The clack is at steady volume, and does not increase or decrease upon acceleration. Engine doesn't run smooth either. I've tried the mechanics stethescope (sp?) and can't pinpoint the cylinder. I did notice the ease of valve adjustment on #1 intake valve, like there was no resistance from the lifter plunger. Could this be the culprit, or should I be looking for something else????? One more question...... Lifters are new, so should I replace them all...or just the one?????????????????
if you have no resistance on the valve adjustment check the rocker arm lock nut. it may have lost its self locking characteristics. If there is no increase or decrease in the noise with rpm changes, look for something else since valve train noise should be increasing or decreasing with rpm. wcj
Checking for a collapsed valve lifter is not that hard to do. Although hydraulic lifters/valves are self-adjusting on most of the valve trains, I've seen people collapse a whole set of lifters by tightening them all the way down and cranking up the motor. In my view, if the valves do not clatter after installing a new cam & lifters you are looking for damage. The good old way of finding free pushrod spin and tightening down a half turn is the best way to start. Crank the engine up and one by one tighten them down slowly(working your way around the engine) until they are all tight.
As far as a collapsed lifter... it's the same concept. Hydraulic lifters should have some spring to them. Pull the valve covers and bump the motor over little by little until you can find some way of turning the pushrod with your fingers. Then simply compress your palm into the pushrod/lifter to see if you can feel any spring action. If you can't find any spring action at all on one you probably collapsed a lifter and are floating that valve when it attempts to open/close. If you find one that is suspect and are still not sure, crank the car up and again press your palm against that rocker arm on the pushrod side to see if you feel knocking. If the nut that holds that rocker arm is tight and there is a knocking I would say you have a collapsed lifter.