From what I read just running the engine might not flush all air out. I think the process generates more speed in the fluid or pressure. The pump is very loud when it runs in the purge process, much different than when the car is running at temp.
Schwarz | Premium | Sport | Nav | Sat | Paddles | PDC | Lead Foot | Hardwired Passport 9500ix w/ Escort Live | Convenience | Matte Grill
| DCI | ALP Jammers w/BT | smoked side markers | Specdock
| rear spoiler | AutoWerke BOV | BMS Oil Catch Can | R1 Cross Drilled Rotors w/ Hawk HPS pads |