I have rebuilt my 3.0ltr. 3vze engine and drove it 60 miles and my check engine light came on! Code was for a knock sensor! After many checks i drained the oil to find it was full of aluminum! (Metallic looking)! I think it is either, oil pump or bearings ! When i rebuilt this engine it took me 2 years to get all my parts and everything was new ! I was wondering if anyone has ever changed main bearings with the engine in the truck by dropping the front differential out instead of pulling the engine again. Any input is greatly appreciated!!