I'm pretty sure my '98 has the same oil cooler. I know they do sell a repair union for the older style oil coolers but don't think that it is available for the W210. Best to call the parts department at the dealer and ask. I would be careful about driving it at all until it is fixed. It would not take very long to lose all of the oil if that came apart while you were driving.

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz