Bad lifter?
I had a small rattling noise under my valve cover (driver side by the firewall). I though the exhaust or intake rocker arm could probably stand some adjustment. After I had gotten the intake valve up all the way, I was able to move the push rod slightly up and down so that it clicked. I adjusted the rocker arm for zero lash, tightened the locking screw. Just after doing that, found that I could still move the the push rod up and down the same as before. I adjusted again and tightened. Same thing again. I could move the the push rod slightly. I ended up doing that 5 or 6 times. Then moved on to the exhaust rocker arm. That had less play but I tightened up anyway. Checked some of the others but none had any play like that one. I buttoned up the valve cover and replaced the intake etc.... Started the car and it idled much rougher than before. I can still here the small rattling noise just has it had been before I adjusted it.
Do you think the lifter is bad and I just tightened the rocker arm too much causing the valve to stay open or something? The car has 160K on it and I never changed out the original lifters although the rest of the valve train has only 30K on it. I did notice that when I twisted the push rod around (like they tell you to do when adjusting the lash), it would get stiff and then easy -- possibly slightly bent? The push rods are relatively new and the hardened type. I'm kicking myself for not changing out the lifters when I had it all apart installing the heads! Anyone have any experience with this?