I don't know that info, but as cheap as it is ($30), I replaced mine while fixing other coolant related issues. Cheaper and less effort than diagnosis...

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2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car