Genuine BMW part 11 51 7 805 811: thermostat with adapter. The number stamped on the part is 11517805811; BMW's catalog files it under the short number 7805811. You will find it on our Engine shelf, under Coolant pump with drive. It supersedes the older number 7789014, so a part carrying that number is the same part.
It fits every E46 body style (318d, 318td, 320d, 320td and 330d, 2001–2005), with the M47N or M57N engines.
BMW draws it on 2 diagrams, among them Waterpump - Thermostat (11_3324) and Waterpump - Thermostat (11_3465). It weighs about 260 g (0.6 lb).
We have not had one on the shelf yet. Request it and we will tell you when one comes off a car.
