My 1994 3.4L has started knocking like crazy under any kind of load. How can I diagnosis this problem? Thanks!

 

Knocking as in imminent bearing failure or knocking as in preignition or pinging?

Hopefully it's the latter. Tried a higher octane gas? My 3.4 had lots of carbon buildup on top of the pistons which caused it to ping on anything less than premium fuel.