My engine has had almost zero oil psi at warm idle for over 10 months and a max PSI of 20 on the highway.No knokcs or ticks and i drive the **** out of it daily.Now I tried 20w50 oil in her and the PSI did not change at all not warm or cold.Is this a signt hat maybe my pickup is clogged? or maybe my oil pump is toast.Next im going to do a oil change with straight 80 and see what happens.The motor also has over 280,000k with plenty of power.Btw these psi readings are from a aftermarket mechanical gauge.

 

Most of these cars at idle have around 10psi, and under load or higher RPM 40-50 psi. Could your guage be faulty?? Also I don't recommend 20w50 for these cars at all. 10w30 at the most. I personally use 5w30 only. Your pump may be getting weak at that milage, but I would try some thinner oil before anything thicker. See how that works for you and go from there.