The engine compartment of an MX5 NB (1998–2000) contains various hoses and lines that carry coolant between the engine, radiator, and heater. They are constantly exposed to temperature fluctuations, pressure buildup, and vibrations, which can cause the rubber to harden or develop small cracks over the years. During maintenance, these parts are therefore often inspected together with the gaskets that seal the mating surfaces between thermostat housings, water pumps, and other cooling components, because it is precisely at those junctions that small leaks can occur.
