how can i tell if my 1990 chevy 1500 with a 350 is knocking? when i start it up you can hear something that sounds like a rattle coming from the engine so i took the oil pan off none of the rods have up and down slack but they have side to side is this normal? is there a possibility that the ristpins are knocking? and you can really hear it from in front of the grill? i know the ps pump is vibrating i can see it or im thinking it could be the harmonic ballancer and the fan has a little bit of slack also. does anyone know what this could be?

 

The side to side clearance on the connecting rods is a required clearance. Can You actually hear the knocking? Has the engine been rebuilt? How many miles are on the engine? Get the vibration problem on the p/s pump resolved. Also make sure that the vibration damper is not out of whack. Wrist pin knock is a sign of a tired engine that needs a rebuilding. A piston noise at cold start is normal in a forged piston application ( more cylinder clearance required ) that will go away once the piston reaches operating temperature. I really need more information and a better description of the knock to help further. It seems like a cold start noise that goes away under operating temperature, Is this correct, if so, it's a normal condition.

 

nevermind i took the belt off and started it and im pretty sure its the ps pump or water pump because i didnt hear it but thanks anyway