my engine is ticking/knocking? not sure.

[crazys13hatch]

i just put a new head on the block. i put brand new rod and main bearings (acl race bearings) about 150-200 miles ago. one thing i did though was put an old spark plug i had in the trunk cuz i broke one from my old head.

the car sounds perfect at idle like theres nothing wrong with it. after 2500 rpms it makes a ticking/knocking noise. could it be the old spark plug that i put on? could that cause a ticking/knocking noise? i also checked if a rocker arm fell off and it was totally fine.

correct me if im wrong but should a car be knocking at idle when the bearings are bad?

oh yeah, the ticking started on tuesday and it does not get worst and today is saturday. i hope i gave you guys enough info, thanks.

[carmo]

Is it a lower end knock or is it more like a valve train tick? Can you adjust valve lash?

[gnr_70]

zerothread?id=377089

any ideas is appreciated.