cobrarwanab
Club Member
I noticed my stock oil pressure gauge in my 85 mustang was periodically loosing all oil pressure. I installed an autometer oil pressure gauge and found i had 20psi at idol. I was also suspecting a cooling issue so i installed a water temp gauge as well. I installed an electric fan with a cheap auto-zone probe style coolant temp switch witch was to close circuit at 180*. When i tested the switch function with the gauge i realized my water temp was 215* and the fan was still off. I think i have my probe in the wrong spot so i am going to move it closer to the inlet of the radiator. My problem now is that after the coolant temp reached 215* my oil pressure at idol is between 9-10psi and only rises to 25psi under throttle. I am thinking the heat effected the oil pump and opened up the vain clearances thus the inability to create pressure? What is the rule of thumb for oil pressure? 1psi for every 1000rpm? and what would i like to see at idol ( 900-1000rpm) It is a stock pump from what the guy told me that sold me the car