I got a 2005 cts. its got a noise that sounds like a rod knock, but when i put it on a lift and listen from below it sounds like its up higher in the block. when i listen closely to the driver side valve cover, i here it the most. What (if anything) could sound like a rod knock in the d.o.h.c. head. thanks nick....[8D]

 

i think it would be more of tick if it was coming from your valves. is the knock deep sounding? is it a double knock?

 

You could have a bad piston pin making the noise. Maybe bad valve spring causing lifter knocking. Is it fast or slow sounding?