Various hoses run through the engine compartment of an MX5 NB (1998–2000), carrying coolant between the engine block, radiator, and auxiliary systems. They are constantly exposed to temperature fluctuations, pressure buildup, and vibrations, which can cause the rubber to harden over the years or develop small hairline cracks. A problem often starts with slight swelling around connection points or a hose that feels less flexible than before. As long as the radiator and other front-end cooling components remain in good condition, the coolant flow stays nice and steady.
