What does cold start knock sound like on Chevy Silverado?
What does cold start knock sound like on Chevy Silverado? Be aware that the radiator cooling fans may operate at any time. Cold start knock is generically called "piston slap," which is common in Vortec engines. For the first 30 to 60 seconds after a cold start, the short-skirted pistons rock inside the cylinders and slap against the cylinder walls, sounding rather like a diesel engine. Why does my 5.3 liter Vortec make a ticking noise? Causes of Startup Noises in a 5.3L Vortec Valve Lifter. Lifter tick is a common occurrence in V-8 engines like the Chevy 5.3-liter Vortec....