Chevrolet Repair: 96 Corvette

Question
There is a light knock on the passenger side of the engine which disppears after the first five minutes it is started. I'm quite sure it isn't a valve lifter.  Since this is fuel injection I would think it doesn't have a manifold heat control valve that might be fluttering--or does it?  I've had a similar problem with my Mopar slant six that has done it for 150k miles which was suggested might be do to a piston issue since if it was a bearing it surely would have failed after all those miles.  The Vet has 170k miles.  Any ideas?

Answer
HI CLEM,NO THIS ENG DOES NOT HAVE A MANIFOLD HEAT EXCHANGER...SORRY...IF THIS IS A LOWER ENG SOUND, THIS NOISE COULD BE A ROD BEARING,STARVING FOR OIL OR BAD, FAULTY RIST PIN ON THE PISTON
THIS IS JUST A GUESS BUT I WOULD HAVE IT CHECKED BECAUSE IF IT IS A BAD ROD BEARING AND IT LETS GO THIS WILL DETROY THE ENGINE..IS THE OIL PRESSURE OK ??? SORRY FOR THE BAD NEWS. GOOD LUCK TO YOU TOM...