When to worry about engine noises?
Not 100% up on Rotella any more, but using a diesel formulated oil in a gasoline engine is very bad policy.
I’m not going to type out all the reasons why because a quick search of the web will explain it.
Think of this. You don’t hear of diesel guys running gasoline formulated oils in their engines do you?
Two completely different lubrication scenarios.
The oil probably isn’t your noise issue, but it’s still the wrong oil.
And 20 pounds of idle oil pressure is WRONG. That’s at the gauge. You probably have 5 pounds of pressure at the rods and zero at the rockers.
Go up a grade or two in oil.
THIS !!!
I had the exact same problem!
Fully balanced and blueprinted stroker 408, Eddie aluminum heads, Diamond 10.5 -1 pistons, Comp Cams extreme energy camshaft, Airgap intake, TTi shorties.
Broke in the engine with Brad Penn, after about 1500 miles, started to hear very noticeable valvetrain noise. Thought it was lifter problem, diagnosed a bad lifter with a stethescope, replaced it and then found another one noisy!! WTF !!
I drained the synthetic Mercedes Benz oil (made by Mobil) and went back to 5W 30 regular oil. Problem solved! No noise!
3 Redseal mechanics could not offer an explanation including the engine builder who has a stellar record for building these engines.
Finally, at work, an oil representative showed up at work so I asked him what he thought.
Exactly as Rat bastid said.
The Benz oil I used , 5w 30 synthetic was specially formulated for diesel engines, says so right on the bottle which I didn't read (stupid me!) and does not work well in gas engines.
I switched to Royal Purple 5w 30 synthetic and no issues since!