280z knock problem - please help with input!

[KenSR20]

I have a 1976 280z and when I crank it up it has a light knock

it sounds like the valves are loose but has been adjusted 3 times.. was told it could be timing chain hitting the chain guide.. with valve cover off it seems to be comming from a valve.

Anyone have any ideas it would be great!

Thanks

[profotoiam2]

i had a knock as something similiar spend the 115 bucks from local auto supply store and put new valves in i screwed up i put mine in to late

[evildky]

youight want to have someone more experienced look at it, a "knock" makes a sort of "clack" noise, a bent or stuck valve makes a "tick" noise and of course having the head reworked is less involved and less expensive

[KenSR20]

Thanks for input will do !!