1970 GTO Lifter Issues
I was hoping someone could assist with advice on my issue. My 400 motor started knocking from the lifter some weeks ago, i thought i would pull the cover to investigate, i took out the push rod and inspected and also adjusted the tension on the rocker which seemed to quieten it down, all else looked ok. I took the car for a short drive and it seemed to lack power and knocking appeared again. I tried adjusting again but rocker is as tight as allows, i noticed that I dont seem to getting the same length of stroke compared to the other rockers. I have taken out the push rod again and it all looks in good order, latest is that the rocker isnt working at all now. When i push on the rod now i think i can feel the lifter compressing which i couldnt do previously.
Does this sound like a collapsed lifter? Would i have damaged the cam? Is it possible to inspect and replace lifters and cam without removing the heads?
Motor was rebuilt approx. 6 years ago by previous owner, car is only driven from time to time and not driven hard, it had been sitting idle for a few months when the issue first appeared.
Any advice would be appreciated, im keen to replace myself if i can.