i have a 72' malibu with its original 350. everything is stock. the engine ran ok but i could hear a few loose rockers and i wanted to tighten them down. i've never adjusted valve lash but thought i could do it and i felt the engine needed it, by how it ran and the fact that no one had kept up with the basics in years. first try i did the entire engine no probs, it started right up and sounded great. later i could hear one come loose and ticking away and annoying the hell out of me when driving.

i redid the exhaust/intake for that cylinder. lost my touch and couldnt get it right.so i redid the whole drivers side for practice. finally got it.

engine sounds like crap though and i hear some hard ticking or tapping noise deep in the engine. i hear it best at the front of the intake manifold. the #7 rocker arm keeps loosening up immediatly after running. ???

when i was adjusting the valve lash and spinning the push rods some would spin fine but others would spin half way then feel stuck and if i used a little force it would spin the rest of the way. are they bent or is thst normal???

sorry this was soooooooooo long

You need to take all of them out and roll them on a piece of plate glass to really tell!

And I have done just this too.................

pdq67

You need to take all of them out and roll them on a piece of plate glass to really tell!

And I have done just this too.................

pdq67

Do this and also check for worn out rocker nuts.

If the lash keeps loosening after you have adjusted it, you probably have one or more cam lobes going away. Sorry.

You mentioned you had never adjusted the push rods before, so it is possible you got some too tight. If the push rods dont spin freely, there likely is a problem with bending. Like one of the others replys said, pull them out and roll them on a flat surface. If they are bent it will be very apparent.

If you adjust the valves with the engine warm and idling, back off the nut until the rocker arm starts to click, then tighten 1/2 turn.

If you have one that seems to back off, notice how much torque it takes to tighten or loosen the nut. They are self locking, and should have resistance to turning in both directions. If this one doesnt have resistance, change it out. It could be backing off.
Good Luck,
TXCR13
66 300 Sedan

Or just maybe a stud is pulling out??

If it is, tap it back down to the same height as the rest and pin them w/ 1/8" x 1" long roll pins.

pdq67