Review on Dromedary Thermostat Housing Assembly 11531437040 for BMW E46 E39 X5 X3 Z3 Z4 325i 330i 525i 530i: High-Quality Replacement Part by Mike Starling

I installed this on my 1999 528i E39 as a preventive measure when replacing the water pump and hoses. This unit failed in less than a year. The heating element that opens the thermostat failed and gave error p1622, which was again confirmed by the readings of the multimeter in the electronic connection. This means the thermostat failed in the closed position and my car overheated. It's not worth saving a few bucks by buying a cheaply made part when it's critical, and if it fails it can ruin the entire engine. Lesson learned here for me.