Not sure why there is oil in it but I believe that is a threaded hole for the tow hook to be inserted and used as an engine lift point.
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Montego Blue E90 335i
7" VRSF IC | OFT Tune | DCI | RB PCV | Secondary CAT Delete & CYBA 3.75" Tips | M3 Front | Mtech Rear | CSL Trunk | 219M | KW V1 | AA CP
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