Replacement thermostat housing for engine cooling system.Compatible with models including E46, E39, E83, E53, E36, E60, E61, E38, E65, E66, E67, E85 vehicles.Fits 3 Series (320i, 323i, 325i, 328i, 330i, 320Ci, 323Ci, 325Ci, 328Ci, 330Ci, 325xi, 330xi), 5 Series (520i, 523i, 525i, 528i, 530i), 7 Series (728i, 730i), X3, X5, Z3, Z4, and Wiesmann MF3 Roadster.Supports engines with displacements of 1991 cc, 2171 cc, 2494 cc, 2793 cc, and 2979 cc.Designed for use with M52, M52TU, M54, M56, and other applicable engine families.Functions as coolant water pump outlet and thermostat housing assembly.Replaces OEM part numbers 11531436823, 11531437040, 11537509227, 1436824, 1437040, 11537509357, 1436823, 7509227, 7509228, 1437039, 11530139877, 649997J, TH32197G1, 432697D, 11 53 0 139 877, 11 53 7 509 227, 11 53 1 437 040, and 11 53 1 436 823. This component is produced by an independent manufacturer.Brand names are used for compatibility illustration.