This problem happens at start up but I have also noticed it when the car is in park or when their is no laod on the engine. It only seems to happen when you rev the engine to 1500 rpm’s. Oil pressure is okay. Car is a 1993 Pontiac Grand Prix with a 3.1L LHO V6 it has 158,638 miles and I use 10w30 castrol oil and fram ultra filters
I have tried lucas oil and thats why my engine has this knock.
The engine will knock only in the morning for maybe 3-4 seconds then it goes away and it will not knock on a hot reastart. If I rev the engine it will not knock. There is no metal shavings in the oil or inside the oil filter.