Car is a swap car so that certainly might explain it....


I've searched various ls1 forums and found a few possibilities for this sound, lifters, rockers, exhaust leaks, etc.

I wanted to post to see if there were any better specific things, it's a unique enough sound that it seems like it would be pinpointed semi-easily enough.

symptoms: accelerate to any rpm over ~1500rpms and let off throttle - still in gear - card in spoke sound from engine bay, the higher the rpm the louder/more frequent the sound is. roll back on the throttle - even the slightest bit and the sound goes away.

any help would be appreciated.

 

Check the flexplate/ flywheel for cracks etc.

 

i have heard that a bad gasket on the air pipe can cause this sound. Not sure if you even have the air system.

 

Air valves... Try blocking off the air valves and see if it continues.