Do not forget to rule out things like DME box fan if the E70 has one, the climate control fan, the HVAC blower (usually sounds like crickets in early models).

But removing the belt(s) can rule in or out accessories and pulleys.

Do not know what is in the cowl area, but when cold on my E70 I hear a slight rhythmic moaning that may be HVAC blend doors or something. Not concerning, but as someone that is "aware" of things, I have noticed this.

I assume it is "normal" but I have not had a chance to drive another E70 for any period of time when the weather is cold.

Let us know what you find.

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2008 4.8i Black with Tabacco. Black Y-spoke wheels and shadowline trim.