Mishimoto MX-5 NA 1.8 Silicone Heater Hose Kit

While most owners focus on their main radiator hoses, the heater core hoses at the back of the engine bay are often a ticking time bomb. On the 1.8L Mazda MX-5 NA (1994–1997), these two hoses run directly underneath the Crank Angle Sensor (CAS). The factory CAS O-ring is notorious for leaking oil, which drips straight down onto the stock rubber heater hoses. Over time, this engine oil chemically breaks down the rubber, turning it soft, spongy, and highly susceptible to bursting unexpectedly under load.

The Mishimoto Silicone Heater Hose Set replaces these vulnerable lines with a heavy-duty, motorsport-grade cooling upgrade.

Crafted from high-grade silicone reinforced with embedded heat-resistant fibers, these hoses feature a robust dual-layer construction. This design allows them to comfortably handle extreme temperatures up to 165°C (330°F) and easily cope with elevated cooling system pressures without swelling or expanding. Furthermore, high-quality silicone offers drastically superior structural resistance to accidental oil contamination compared to standard OEM rubber.

Finished in gloss black, this kit drops directly into the place of your factory heater hoses, connecting your engine block and cylinder head to the firewall heater core.

Features:

• Direct fit for 1994-1997 Mazda MX-5 NA 1.8L engines
• Replaces the two primary heater core hoses at the firewall
• Dual-layer construction: premium silicone with embedded heat-resistant fibers
• Gloss black finish for a clean, stealthy engine bay look
• Significantly higher temperature and pressure tolerances over OEM rubber
• Rated for temperatures up to 165°C (330°F)
• Mishimoto Lifetime Warranty

Installation:

• The “While You’re In There” Upgrade: Reaching the heater hoses at the firewall can be a tight squeeze. We highly recommend swapping these out whenever you have the coil packs off, during a clutch job, or when installing a coolant reroute kit.
• Clamps: To preserve the slick finish and long-term integrity of your new silicone hoses, we strongly advise using high-quality stainless steel worm-gear clamps instead of the sharp factory spring clamps.

Compatible with 1994-1997 cars – NA (Mk1) 1.8 engine ONLY.

Shipping worldwide.