I finally get my motor all wired and cooled properly and I run into this...


New opti, wires, plugs, waterpump, fresh 15W-40 oil. Running 40 psi of oil pressure at 190 degrees F.



I didn't notice this knock in the 1997 donor car, but I also didn't have it at operating temperature. I know the computer is tuned for a LT4 Hotcam, but I doubt it would make the motor sound like this.



I believe it sounds like a bottom end knock, but maybe I could get some insight before I spend money on a rebuild.

 

Im not positive, but on my phone it sounds like it spun a bearing. Like i said though, im on my phone. LTx is notorious for spun bearings.

 

I recommend taking it to a mechanic and having it checked.

 

sounds more like rod knock to me

 

I agree on the rod knock and even with the oil you are using..once its switch to something lighter the knock will be more evident.

 

Looks like it's time for an overhaul. So much for the summer car making it on the road this year. Thanks for the help.

 

go on eBay and look for a member called kmj performance. They carry re build kits and re ring kits for cheap.