Taho engine oil pressure low
Maybe the guage or sending unit is bad,,,by a maual guage and check the presure,,,hook it up where the sending unit is on back of engine diverside left,, lower where intake bolts to the intake,,i would change the oil and filter, first,, with a little heavier engine oil,,, 10w30 or 10w40 highmilage....,,, 5.3 holds 5.75 quarts