http://www.youtube.com/watch?v=mSJXdi3uH4Y

Only happens after warm up.
Not all the time either.
Goes away once I get above 2k.

Lifter? Bent PR?
Valvetrain is stock as far as a know.
Has done this for a little while now.
About 38k on her.

I use GC0-W30.
-Matt

 

Not saying its the same, but mine sounded exactly like that... I pulled the valve covers off and took the rockers out and I had a nasty bent pushrod....

 

It's all stock? I would pull on the passenger valve cover.Look at the Pr's and rockers. It's not that difficult to pull that cover off.

 

What would cause a pushrod on a stock motor to just bend? Beating that hell out of it obviously, but what if it wasn't beat on?

 

normally over rev, missing a gear and revving too high or having the car under load trying to get everything you can out of your car normally.

 

Sounds EXACTLY like my 02 with 37k on it. It runs fine and like you mention above 2k its quiet. I think ALOt of 02 ls1's had this noise.

 

My brother has an '02 WS6 and his does seems to do that too. I too believe it may be the rockers.

 

just good ol' chevy lifter tap... you got it worse than some ive seen, but if you get no codes and your idiot-light isn't on then i wouldn't worry about it. if you've just changed plugs and it skips, or it idles rough, you cracked a plug or broke a plug wire.

 

In any case it wouldn't hurt to spend less than a hour to check to see if it is a pushrod cause if is, then things will just get worse... Has it always been like that or just start. sounds exactly like mine was...

 

Mine's had the same tick since I got her about 3 years ago. Every chevy tech that I've talked to said its normal for the LS series. They said if it goes in and out its ok, but when you have the tick ALL the time, that's when you need to tear apart the covers and check stuff. Are you tripping any lights?

 

Several LS1 noises sound like that...piston slap, lifter tick, bent pushrod. Did the 02s have the piston slap noise? You can check the PRs easily as noted above. That at least eliminates one choice. My car doesn't sound like that now, but it did when I had 3 bent pushrods.