not enough.

Agreed

You might want to switch to a 10w30 oil at your next oil change or add a quart of lucas oil stabilizer to help with the oil pressure. It won't fix it but it should help extend the life of your engine.

I turned up my speakers to try and replicate actual volume, and I do hear a slight knock when you rev to about 2K. Sounds almost like a cold diesel. It's a constant knock and the pitch changes slightly. I have heard that sound before and driven like that for months with no problems and I had almost exactly the same oil pressure and mileage.