Hey all, long time lurker, first time poster. First off, thanks for everyone who posts. I have a 2011 QX56 that we have owned for about 8 months, just yesterday the engine made a loud whirring noise like a semi truck, and seemed to shift a bit later than normal. I didn't think to toggle A/C but this morning the engine sounded normal. Based on the sound/further description: if it had an electric fan I would guess it was stuck on high but of course it doesn't, and the loudness/pitch was directly related to the RPMs. Again, we have had the vehicle for a while now and have run the A/C plenty, any thoughts? This post is the closest I could find to my issue, but it certainly doesn't seem normal. Thanks again all.
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