Good morning, a k20z3what engine are we talking about?
Did you replace the oil pump for the exact same type that was in there before ? if you went from balanced to unbalanced, you need to block an oil way or you lose a lot of oil pressure at low revs.
What bearing clearances where chosen? Where they confirmed with plastigauge measurements?
This could be rod knock from excessive clearances and/or too low of an oil pressure.
As long as the engine oil is cold, idle oil pressure is large enough to cope with both issues.
The pump was replaced with a type-r hot oil pressure is ok around 2.8bar (25 psi)
crankshaft and connecting rod bearing clearances all TSD
this noise do you think it could be (connecting rod or valve control)
Connecting rods or bronzing and new node recently exchanged for king racing black STD