You can try tightening it but before you do I suggest you get a sense of how tight is tight enough but putting a wrench on one of the other ones and feel how much pressure it takes to move it. If you have a torque wrench that would be the best way to measure how tight it needs to be. You can also try some silicone on the threads.

In your case I suggest taking it back to the dealer as there is a 2 year warranty on parts.

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