What kind of engine do you have? I did mine on my W124 (M104 engine), and for a dim-wrench like me who has never done a radiator before, it took all of an hour and a half for the removal and subsequent install of the new one. Did the p's and q's for another 1/2 hour on the following day before starting up the car and testing...

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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