6.5 Unusual Knock
 

Hey so I just swapped in another 6.5 into my truck this one has 187000 kms and newer injectors and injection pump. But the thing has started to knock once the truck starts warming up and the oil psi drops to 40 ish psi and rpms are around 650-700. Its not a usual knock of a 6.5 and the ecu isn't storing any codes but it doesn't sound good to me. Any suggestions?

Knock associated with low oil pressure is never good-bearings and/or crank problem likely.

The blocks with oil squirters for the pistons require a high volume oil pump.

I know somwtimes in rare occurrences a knock and low oil pressure on these and be caused by a main saddle that cracked almost all the way...not very likely but a scary thought