Oil Cooler whine?

[houkouonchi]

Is this normal? I am getting a slight whine after I got an oil cooler installed by Nissan.

Here is an audio recording of the whine but its not super easy to tell in the recording (used my iphone):

http://box.houkouonchi.jp/20110824%20124034.m4a

This whine doesn't bother me *that* much if it is normal just was unexpected. Otherwise I am really happy about the decrease in oil temps though. It was hot on my drive back (almost 100F) and the temps stopped raising at noticeable speed once it got up to about 170F. It didn't get up to 180F until almost 10 minutes on the freeway and got up at around 185 F (and topped off) by the time I got home (23 miles into the drive).

I can definitely live with the whine if that's normal.

Here is a snapshot from my iphone @ around 6 miles into the trip (mostly on the freeway):



Before when it was about this hot out I would see oil temps in the 235-240 range.