When does a car make a knock noise?

When does a car make a knock noise?

Some of the above vehicles may exhibit an engine knock noise that begins in the first several thousand miles/kilometers of use. The knock noise is most often noticed during initial start-up and typically disappears as the engine warms up.

Why does my GM Truck make a noise when I start it up?

These engines generate noises during cold start and during warm operation that technicians may not be familiar with. The latest generation of full-size trucks and utilities incorporate a new generation of technologies not previously seen in a GM full-size truck and utility applications.

What’s the knocking noise coming from MY Suburban?

I recently ran into this same knocking/ ticking issue coming from my 2005 Suburban, 5.3 Vortec. After countless hours of research, multiple engine flushes, oil change, air filter, valve adjustment…etc etc etc…my solution and problem were relatively simple.

What causes a loud cold start knock noise?

I don’t think there is anything (maybe a rebuild) that will fix the piston slap. The lifter noise is usually dirt and, or wear, that lets the lifter “bleed down”. Sometimes as @ Conlan Rose suggested, it might be a slow to build oil pressure issue, that is caused by a dirty oil filter, sometimes it’s clogged oil passages.

Some of the above vehicles may exhibit an engine knock noise that begins in the first several thousand miles/kilometers of use. The knock noise is most often noticed during initial start-up and typically disappears as the engine warms up.

These engines generate noises during cold start and during warm operation that technicians may not be familiar with. The latest generation of full-size trucks and utilities incorporate a new generation of technologies not previously seen in a GM full-size truck and utility applications.

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.

Where can you hear the knocking of the engine?

The knocking can be heard around the top of the engine, but is much louder if you listen in the front wheel wells or beneath the truck. After a few minutes, engine heat closes the piston/cylinder tolerances and the knock goes away.