Hey guys quick question. I jsut recently built a vortec 350 tpi and I have an engine knock. it only does it when the car is cold or has been sitting for a while. The block is out of a 98 chevy 2500 pickup. I did a search and it looks like this is a common thing for those blocks. anyone have any qxperience with this? also could it be a dead lifter waiting for oil pessure?

It is really hard to say without us being there.

Maybe with a video we can see what you mean.


Did you check the rod and main bearing clearances when you assembled the motor? Were they within spec?

Everything was within tolerance. It does not sound like it is deep in the motor. It almost sounds like piston slap or a dead lifter as if there is no oil getting to a lifter, or very little. I did a search on the net and the L31 blocks have issues with excessive piston slap when the motor is cold. Not sure how true that is or if I got a dud of a motor. The weirdest thing is that the motor runs great and the noise goes away after a minute or two when the motor warms up.