I just picked up this 2002 WS6 with 109,000 miles and a nasty rattle. The car turned off quiet, and started up like this. The car is bone stock with a muffler welded in. the engine has never been cracked open and still has good oil pressure even with the rattle.

it's very loud, very fast and fluctuates with RPM. My guess is a lifter eating up a cam lobe because it is so fast. It's a complete guess It almost seems to fast to be a lifter too?

 

It does sound top end related though. Time to pull the valve covers to check the easy stuff first.

 

Its completely trashed and the only fix is a full rebuild. Top to bottom, included the intake manifold and oil pan. May as well replace the block too

I'll do you a favor and take it off your hands, free of charge. I don't normally do this kind of thing, but for family- I'd be happy to



Sounds like a rocker to me, kinda

 

Sounds like something in the top end, maybe a rocker lost its bearings.

 

Probably a lifter/cam.

Does it lessen as the engine warms up?
Any misfires?

 

It's too fast. Take the belt off to make sure it isn't in the power steering pump. I think I hear it in the power steering pump because it's in the center of the video,

From what I can figure out in this metronome app I just downloaded on my phone for free, it seems to be about 900 beats per minute. A weird number that isn't a multiple of anything that makes sense, There, I am a tremendous help.

 

i havent been willing to let it run long enough to warm up. The belt is the original2002 so i may reach in with a knife and cut the belt as mikegyver suggested just for the hell of it. Its throwing a p0300 but was throwing that code before the rattle started.

I still claim to be a truck guy, but now have 2 trans ams and the camaro…eww

 

 

Lemme come get that black trans am

 

it may be idling 900rpm cold…