when I start my 22re it sometimes makes a "clank" noise at first. this doesnt happen every time and it doesnt depend whether its a cold start or warm. it only happens for about a second then stops. i was thinking this could be knock or possibly slack in the timing chain (bad tensioner). is this really bad or should i just let it be.

its probably clanking until the oil gets pumped up to the valves. my 87 4runner did that, but i didnt really worry about it

thanks that saves me a lot of heartache

I would suggest pulling the valve cover and check the timing chain guides they may be broken