Onyx_Black_Z28

iTrader: (2)

This is not my car, but my near stock Z28 makes the EXACT same tapping sound when it's cold. Does this sound like piston slap to you guys? Is this a normal sound?

http://www.youtube.com/watch?v=_lS3Z...layer_embedded

Thank you very much for your help in advance.

Onyx_Black_Z28

iTrader: (2)

Bump! Any feedback is appreciated, whether it's "What sound?" or "That is NOT normal" - just trying to get a feel for whether or not this is a normal sound for LS1's!

majeskyb

iTrader: (1)

I have the same sound when it's cold. Usually worse the colder it is outside. My noise usually goes away within a minute of starting. From what I've read on here, I'm assuming that it's piston slap.

Paul Bell

iTrader: (9)

Sounds like piston slap to me. My car does the same cold. It was a bunch worse until I went to a lighter oil. German Castrol 0W/30 here.

The heaviest oil used in a street driven LS1 is 10W30.

TransAmWS.6

Yeah, I'm pretty sure that's piston slap, mines sounds just like that when cold and it doesn't really stop until it gets close to operating temperature. LS motors are notorious for making valvetrain noise so I've just grown to ignore it pretty much.

Onyx_Black_Z28

iTrader: (2)

Ok great - thank you all for your responses! The research I've done seems to indicate the same.