Tick, Tick Tick, I think it is a rod bearing.

[Hammer Down]

I rescued a 1992 NX a year and a half ago form the inevitable crusher.  Good
body but was neglected on the mechanical side and the wheels were stolen.
Figured I could save it, get it running as a inexpensive mode of
transportation and have fun whilst doing it.  I replaced the engine with an
import unit and neglected to inspect, clean and lube the rod bearings.  BAd
Erik, Bad!  about 4k after the install, the engine started developing a
metalic "tick" or light knock sound under acceleration.  I figured maybe it
was the upper TC guide or a worn Tensioner...  Removed the guide, changed
out the tensioner (to the new style).  Still doing it but now you can hear
it under steady load too... DAmn!  If the bearing material hasn't been worn
through and the crank and rod surfaces look good, can I just replace the
bearings?  Can I drop the cross-member and pan and do it witht he engine
still in the car?

TIA,

Erik, occassionally a dumbass....

Check out my new addition....
http://s48.photobucket.com/albums/f231/hammer_down/240SX%20GTS-t/