Hey, I'm looking into buying an 89 camaro. 500 bucks, pretty good looking car, but it makes a loud knocking noise from the left side of the block, but the engine was swapped from a 1986 camaro, and it was supposedly new, or rebuilt. Any Ideas, the knocking is semi random and loud.

 

Is it more of a hard knocking sound like a hammer, or a lighter metallic tapping sound?

Could be a rod bearing or main bearing (although those two not likely if it is actually coming from the left side of the block); wrist pin, or valve train. In the valve train area, it could be a broken/bent pushrod, bad lifter, somehow damaged rocker arm, broken valve spring, or rocker arm stud pulling out. Have also seen valve spring keepers come out.

May be other causes, but most of them require some level of engine disassembly or removal.

 

Hmmm, somehow I read "86 V8". Not sure whether the V6's had press-in or screw-in rocker studs.

 

should have screw in studs ( now watch me be wrong )