hello everyone i have a 2002 Z28 with the LS1. IT has a engine knock until It warms up to temp.just wondering if this is a normal thing with the LS! thanks you for any info.
mike

 

Are u sure it is an engine knock, or just a valve lifter making noise till it pump up?

 

thks for the re ply.It could be lifter noise it has only 35000 mi on it.
but when i first start it there is no noise after a min or 2 is when the noise starts .
then once the engine gets up 2 temp it goes away.
if i go to town and shut it off for 5 2 ten min. and restart it u can again until it gets back up 2 full temp. was thinking that mabe this was normal for the ls1 ???
thanks again
mike.

 

Could be what is known as piston slap, it's pretty common in LS1's

 

I have that same knocking noise in my ls1 at the same time's as well. I think it might be what JD is talking about, piston slapping. Its common. Just get a loud exhaust system to drown it out lol I can't wait to put some louthmouth's on mine

 

thank you for the reply. yes i think u are right. i made a phone call to slp and they said the same thing.
thanks again
mike

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just want 2 say thank you. for everyones help.

 

Piston slap. From the factory there is a almost five-thousandths of clearance as opposed to a standard SBC with 2-3. The extra clearance gives the aluminum room to expand when hot.