Cooling system overhaul on E30 M3, do it all at once

The S14 runs hot, especially on track. When one cooling component fails, the rest are usually not far behind. I replace the water pump, thermostat, all hoses, expansion tank, and temperature sensor as a complete set every five years or 80,000km. The expansion tanks crack and dump coolant without warning. The aftermarket Mishimoto aluminium radiator is a worthwhile upgrade if you do any track work. Total cost for a full OEM refresh is about $600 in parts. Cheap insurance for a $60,000+ car.