The thermostat is located in a plastic housing somewhere in the piping between the top of the radiator and the engine. This is my guess also.
You may only have electrical fans. However, if you have one big fan connected directly to the engine then you should check the viscous clutch at the center (centre
) of the fan. On the 2.3 engine in the W124 mercedes used an electro magnetic big fan which was triggered by a switch at the top of the engine I am not sure if they changed it to the viscous clutch one in the W210 2.3, you need to confirm that.
You need to get yourself a book or a technical manual for your car it will make things a lot easier for you if you are a novice.
By the way your link did not show. Re post it if you can by typing out the http//: path here.