Cooling System: Diagnosis Mazda MX-5 NC

ENGINE COOLANT LEVEL INSPECTION [LF]

Note. If the "FL22" mark is shown on or near the cooling system cap, use FL22 type engine coolant. FL22 type engine coolant is shipped as a diluted solution (55% coolant, 45% water). Use the solution as is when replacing coolant.

Scheme 2

1. Verify that the engine coolant level in the coolant reserve tank is between the L and F marks.
2. If the engine coolant level is below L mark, add engine coolant.

Scheme 3

1. Measure the coolant temperature and specific gravity using a thermometer and a hydrometer. CAUTION: Use engine coolant at a concentration that meets the environmental conditions in which the vehicle is driven, otherwise engine damage could occur. The engine has aluminum parts and must be protected by an ethylene-glycol-based coolant to prevent corrosion and freezing. Do not use coolants containing Alcohol, Methanol, Borate or Silicate. These coolants could damage the cooling system. Use only soft (demineralized) water in the coolant mixture. Water that contains minerals will cut down on the coolant's effectiveness. Engine coolant damages paint. If engine coolant does get on a painted surface, rinse it off quickly. NOTE: If the "FL22" mark is shown on or near the cooling system cap, use FL22 type engine coolant. FL22 type engine coolant is shipped as a diluted solution (55% coolant, 45% water). Use the solution as is when replacing coolant.
2. Determine the coolant protection level by referring to the graph see scheme 4 If the coolant protection level is not correct, add water or coolant.

ENGINE COOLANT LEAKAGE INSPECTION [LF]

Scheme 4

1. Inspect the engine coolant level. (See «ENGINE COOLANT LEVEL INSPECTION [LF]»(ref-244456-S27052262722006092400000) .)
2. Remove the cooling system cap.
3. Clean the installation parts of the cooling system cap.
4. Install the SST and a radiator cap tester to the coolant reserve tank filler port.
5. Apply pressure using the radiator cap tester. CAUTION: Applying more than 122.6 kPa {1.25 kgf/cm 2 ,17.8 psi} can damage the hoses, fittings, and other components, and cause leakage. Pressure 122.6 kPa {1.25 kgf/cm 2 , 17.8 psi} [1 min]
6. When pressurizing the cooling system, verify that the pressure is maintained. If the gauge needle drops, it may indicate water leakage. Repair or replace the applicable part.

Scheme 5

1. Clean the cooling system cap and the sealed part.
2. Inspect for cracks or roll up on the sealed part of the cooling system cap. If there is any malfunction, replace the cooling system cap.
3. Attach the cooling system cap to the SST and a radiator cap tester.
4. Hold the cooling system cap downward and apply pressure gradually. Verify that the pressure is held stable for 10s . If the pressure is not held stable, replace the cooling system cap. Cooling system cap valve opening pressure 93.2-122.6 kPa {0.95-1.25 kgf/cm 2 , 13.5-17.8 psi}

THERMOSTAT INSPECTION [LF]

1. Inspect the thermostat for the following. WARNING: During inspection, the thermostat and water are extremely hot and can cause severe burns. Do not touch the thermostat and water. The valve should not open under normal temperature. Opening temperature and valve lift If there is malfunction, replace the thermostat. Thermostat initial-opening temperature 80-84°C {176-183°F} Thermostat full-open temperature 97°C {207°F} Thermostat full-open lift More than 8.0 mm {0.31 in}