Had to replace the original engine at 125,000 miles, Knock sensors started going off and after investigating fount that one of the cams had damage. Replaced engine with a long block from a national rebuildrer. Have about 10,000 on new engine and at idle there is a random knock. You can turn it off and when you restart no knock. I checked and it is not triggering any codes.
Any ideas?
Thanks

 

Try removing the serpentine belt to eliminate a possible FEAD accessory. Could be several things but with only 10,000 miles its time to find out how reputable the rebuild company is. I'm sure it has to be under warranty mileage wise unless its out because of number of months. Call them and have a rep meet with you. Good luck