Quote Originally Posted by Raven225 View Post
Follow Up to Oil Pressure Issues

Oil Setup Info:
-Killer B Aluminum Oil Pan
-Killer B Ultimate Pick up
-Killer B windage tray
-OEM 11mm Pump
-No OEM Oil cooler/warmer
-10w40 Motul Break in Oil
-OEM Oil Filter
-Oil Pressure Sensor is located up top back by the turbo
-Oil Temp Sensor is located at the bottom of the Oil Pan

I finished up the temporary wiring for my Oil Temp Gauge and ran the car again. I started the car and let it idle for ten minutes. The oil pressure gauge was indicting 90-100psi at start up with a rpm of 1300rpm. After the ten minutes of idling the oil temp was up to 140F and pressure was 50psi at 700rpm. I gently drove around the neighbor hood (4 miles of 20-30mph driving rpm never above ~3000) I was seeing oil temp creep up to about 160F and 100psi at 3000-3500 rpm and ~35psi at idle (~500rpm). I pulled into the parking lot of the park by my house to look everything over. When I stopped the Oil Temp moved up to 170F, but dropped back down to 160F as soon as I started driving again. I drove another 4 miles back to the house and the oil temp never got higher than 170F. Which is not operating temp.

Any ideas as to what the cause of low oil temp? I figured that idling for 10 minutes would be enough to get it up to temp, but maybe the oil temp sensor being in the bottom of the oil pan has something to do with it?

Another thought, does oil weight have a linear curve when it comes to pressure? for example I am running 10w40 when I switch to 5w30 oil will PSI be 25%-50% less? I am a little confused about the scale for oil weights.
High RPM and power create the energy and flow to heat the oil. At idle you are making little power, energy or flow. Testing for your highest oil temperature requires high load and high RPM. 200F is a good temperature and 270F is an upper limit. 300F is bad. Oil pressure is high with cold oil because thick oil does not flow easily. At operating temperature and higher RPM the oil pressure is regulated and you see that on the gauge, although by positioning the pressure sensor away from the pump the reading is less accurate. 5W vs 10W is significant to distributing oil when cold and the cold pressure issue is discussed above. Hot 30W vs hot 40W will not be distinguished by your gauge.