Subaru Outback Forums banner
1 - 1 of 11 Posts

· Registered
2,812 Posts
I'll take a guess. Viscosity of fluids thickens as temperature decreases.
That thick fluid has to travel through restricted orifices in the engine/trans/powersteering. As fluid is pumped through these areas, it is forced to speed up, pressure builds and aeration occurs. The whine is from the aeration.
A mechanical engineer might explain it better.
1 - 1 of 11 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.