Abstract: The invention concerns a device and method for cooling and preheating, especially of transmission fluid, of an internal combustion engine, with an equalization tank, with at least one radiator, which can be connected by means of an engine thermostat when a predetermined temperature is reached in the cooling loop, and with a water/oil heat exchanger. It is prescribed according to the invention that the forward stream (1) of a single water/oil heat exchanger (5) be branched off in the heating phase by means of a valve unit (3) essentially from the main cooling loop (12) of the internal combustion engine (17) and that its forward stream (1) in the cooling phase be taken by means of the same valve unit (3) essentially in the coolant side stream (13) from the low-temperature region (14) of the radiator (4) or a separate low-temperature cooler (14a) connected in the side stream after radiator (4, 4a).

Abstract: A thermostatic valve assembly includes three housing components (16, 18, 20) containing two interconnected chambers (64, 78). A first thermally responsive valve unit (68) is disposed in the chamber (64) while a second thermally responsive valve element (98) is disposed in the chamber (78). Both the chambers (64) and (78) have inlets (60, 110) and the chamber (64) has an outlet (66). The valve may assume configurations allowing a minimal flow (FIG. 2), a large volume warm up flow (FIG. 3), a mixed flow regimen (FIG. 4) and a pure cooling flow regimen (FIG. 5).