jak2908

iTrader: (1)

i have a 2000 z28 with 132K on it and i just bought it a couple months ago with about 127K on it...it recently has been having some engine noise...on a cold start the initail first 20-30 seconds its quiet.. then after that it idles down just a tid bit and it starts to have a slight knock..i think it is a rod bearing..my buddy thinks its a wrist pin..the knock goes away when the engine is warm

ND400

Mate, id be getting that thing on a hoist asap and having a good listen. It may be piston slap

KevinR

If it goes away after the engine is warm, then it is probably just piston slap.

jak2908

iTrader: (1)

so i should probably be tearing it down this winter???

blue98Z

iTrader: (29)

No need to tear it down. Piston slap is completely normal in these LS motors.

jak2908

iTrader: (1)

it sure scares the hell out of me tho..not something i want to be hearing

twelver12

iTrader: (3)

is it a sloppy sort of sound or a hard knocking sound

Ruthless909

iTrader: (19)

That's an F-body for you.

jak2908

iTrader: (1)

kinda sloppy...kinda like a rod but doesnt make sense to be a rod after it warms up..cause after its warm its all fine and dandy..runs like a raped ape

HotSilverBird

Its completely normal...ITS YOUR PISTONS! fergit about it.

nasmith67

and have been told that it's my lifters and should not be worried about it. i have to ignore that talk tho cuz it's not their car to deal with. i hate the sound of it!!!! unlike the thread starter my sound starts from the turn of the key and goes in and out. it does stop most of the time but if i rev the engine i hear the sound again and as the revs drop it fades out