knocking when first started (ls-1)

[LETHALxLS1]

Hi,
I have a 98 z-28 that I just bought 2 months ago. When I first start the car for the first time of the day it makes a knocking/tapping sound for about a minute. After that the noise goes away. I can start the car immediately or 3-4 hours later and the noise does not occure at all. If I let the car sit for about 6-7 hours it will make the same noise again for about a minute. Does anyone know what this could be ???? Thank you very much any help is greatly appreciated.

[SSee ya]

how many miles on it?

[nc98z]

piston slap which is a normal condition for an LS1.

[shady milkman]

piston slap which is a normal condition for an LS1.

dont worry about it! its normal

[turbotko]

Slappy slappy. It's a bit unnerving to hear your LS1 make this noise but it is normal.

I'd trash GM for building these engines that are prone to piston slap........but it's such a damn good engine and I can deal with the sowing machine under my hood!

[LETHALxLS1]

it has 65,000 miles and has made the noise ever since I bought it.

[LETHALxLS1]

Thank you guys it damn sure had my nerves shot.
I never heard anything like this in my previous camaros.
But then again I never had above a 87 model iroc before
this 98 I just got!!!

[m6speed]

if your ls1 doesn't sound like a sewing machine/ticking beast than it isn't an ls1

[shady milkman]

GM fixed that damn slaping in the ls2..i moved to a floating pin in the design..i believe you can swap em' out and eliminate it...but yea ls1 slap more then ike did to tina turner..and thats alot

[LETHALxLS1]

hahahahahahah Ike and Tina thats funny man!!!!
Thanks for the help!