Join Date: Dec 2009
Location: Cincinnati OH
Car: 01 OBW, 2.5 4AT
Feedback Score: 0 reviews
Same thing happened to me a year ago - the noise got worse as the weather got colder.
You could also run the engine, pull the intake piece, uncap the PS resivoir and see the bubbles churning up through the system.
a new o-ring on the pump inlet solved the problem. Pretty easy to do as far as car repairs go.
'01 OBW 4AT, 170k
'09 Kia Sedona