I don't remember but there might be a test function that shows RPMs if you open the cluster. Otherwise, there are apps and code readers that provide realtime info. I don't know the exact RPMs showing. Usually about that amount over the first mark is fine. That was my reference. Many M54s idle at 650rpms and many 750. Regardless of what the idle spec is the engine should not miss where the needle is in the picture. When you determine the idle rpms the engine should be at operating temp. Check with air off and as little electrical load to show max idle. Then turn everything on and check the idle rpm again to verify it recovers, doesn't drop at all or not enough to matter.

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X5 4.6 2002 Black Sap, Black interior. 2013 X5M Melbourne Red, Bamboo interior
Dallas