Engine Knocks

[cparks555]

My 2007 5.3 Sierra makes a knocking or pinging sound when starting from cold. Once the engine warms up the sound mostly goes away. Before I take it in for service, I was wondering what could be happeninig?

 

Thanks

[jro909]

all vortecs knock, its a trademark lol...if i start my truck after sitting in freezing weather all day it will sound like a pinball machine for about 30 seconds

[cparks555]

all vortecs knock, its a trademark lol...if i start my truck after sitting in freezing weather all day it will sound like a pinball machine for about 30 seconds

 

 

Thanks man, Just noticed it since it started getting cold here, sounds terrible for about two minutes. I mean you can hear it pretty good. Is this a normal thing for these trucks.

[jro909]

all vortecs knock, its a trademark lol...if i start my truck after sitting in freezing weather all day it will sound like a pinball machine for about 30 seconds

 

 

Thanks man, Just noticed it since it started getting cold here, sounds terrible for about two minutes. I mean you can hear it pretty good. Is this a normal thing for these trucks.

 

 

 

yes its called piston slap, something to do with the skirting on the pistons needs to expand(thus it needs some heat) its not harmful and i can gurantee almost everybody on this board that drives a newer gen vortec has the knocking...nothen to worry about, once you get a few miles on her the thing will sound like a pinball machine on cold start ups..almost all v8s on the market have some sort of weird ass sounds to them from my experience...drive on and enjoy the truck

[cparks555]

all vortecs knock, its a trademark lol...if i start my truck after sitting in freezing weather all day it will sound like a pinball machine for about 30 seconds

 

 

Thanks man, Just noticed it since it started getting cold here, sounds terrible for about two minutes. I mean you can hear it pretty good. Is this a normal thing for these trucks.

 

 

 

yes its called piston slap, something to do with the skirting on the pistons needs to expand(thus it needs some heat) its not harmful and i can gurantee almost everybody on this board that drives a newer gen vortec has the knocking...nothen to worry about, once you get a few miles on her the thing will sound like a pinball machine on cold start ups..almost all v8s on the market have some sort of weird ass sounds to them from my experience...drive on and enjoy the truck

 

 

Good to know, thanks for the info.

[ChevyTech77]

It may have a lot of carbon build up on the piston tops that can make this noise worse, also.

A good top engine clean/fuel tune will clean it up.

[markw8]

Chevron Techron Plus in a couple of tanks should help with carbon. Or BG44k if thats not enough.

 

Mark

[cparks555]

Chevron Techron Plus in a couple of tanks should help with carbon. Or BG44k if thats not enough.

 

Mark

 

Thanks guys, sounds like a pretty simple solution. I will definately be adding some to my next tank of gas.

[ken1mod]

My '00 Silverado 5.3 sounds like a box of rocks for about 1 minute then gets as quiet as a new perfect engine. This at 161,000 miles. I guess it is safe to say it does not hurt anything. You should hear my brother complain about his new Mercedes that does the same thing.

 

Ken

[thebandnerd03]

Yeah Any one with a vortec will tell you that the engine sounds like its throwing every rod in the engine till it warms up. the reason is that the piston sleeves are a little thinner on the new gen of these engines so they expand and contact more then the older models. no need to worry. Just dont throw the hammer down till its a little warmed up and you should have no problems.