RandomSSHero

iTrader: (1)

The 04 GTO started doing this today. We're unsure what it's coming from... lifters, springs, rods, bearings??? It does this at idle and when rpms increase it gets faster. Warm or cold, doesn't matter. The car is in a parking lot and trying to figure it out to determine if we can fix it there or not.

Stock internal LS1, 55k miles. Camshaft: 232/236 FTI Custom Camshaft. .600 lift. Heads: Z06 #243 casting. These have the lightweight sodium-filled valves. Professionally installed Patriot Dual valvesprings.

Video: http://www.youtube.com/watch?v=H0xdm6Md5y4

Thanks!

LS1CMR

iTrader: (12)

could be a rod bearing, broken spring, video is very vague, do you have a mechanics stethoscope, it will help you pinpoint where itscoming from

fortmyerspolice

iTrader: (7)

Sounds like its coming from up top. Just pull the valve covers and check everything.

TORCHD 02 TA

iTrader: (39)

well i would stop running it immediately. Sounds like a rod knock to me.. Good luck