With various aspects of servicing, maintenance, including driver assisted features and vehicle monitoring. For our 1996 Rover 200 and the 04 ZR 120+
How the cooling system works, the water pump first pushes coolant..into engine block which then flows into the cylinder head getting hotter as it circulates, hot coolant then exits from coolant elbow. Along top hose into radiator to be cooled, then out of bottom hose up along the coolant rail to the thermostat, then back to water pump, so constantly repeating the cooling process.
Coolant elbow joint In conventional systems, the thermostat is usually located on the outlet from the engine, the location on the K Series is at the rear, allowing the engine to reach its temperature more quickly and evenly with short periods of opening and closing.
As vehicles heater control knob is rotated to cold position, the control valve located on bulkhead will close, so no hot coolant will circulate within the cabin heater, via the SAAB C900 heater matrix valve.
Cabin heater, or heater matrix, is basically a smaller version of the cars radiator, filled with hot coolant supplied via the smaller of the two elbow joints coolant hose, which then feeds hot air into the cabin as and when required, and is located in the cabin in an enclosed area between the centre console and engine bulkhead. The matrix heater does not require any form of air cooling properties.
A coolant circulation check is to feel the radiator top hose it will be hot, and radiators bottom hose should be warm after coolant has been cooled prior to it going back into the engine to continue on its re-circulating cooling process.
Worth taking note that the temp gauge which usually shows a tad below half after a drive on these vehicles, Will not always be an indication that the engines (actual operating temperature) has yet been fully achieved till after a further short period of time.
Information supplied is referenced only to our own 1996 Rover 200 Series, and 2004 MG-ZR 120+