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Cooling System: Diagnosis Mazda 3 BK

Cooling System (Mechanical) 3 illustrations ~367 words

ENGINE COOLANT LEVEL INSPECTION

WARNINGRemove and install all parts when the engine is cold, otherwise they can cause severe burns or serious injury. Turn off the engine and wait until it is cool. Even then, be very careful when removing the cap. Wrap a thick cloth around it and slowly turn it counterclockwise 2.5 turns. Step back while the pressure escapes. When you are sure all the pressure is gone, turn the cap using the cloth, and remove it.
  1. Verify that the engine coolant level in the coolant reserve tank is between the MIN and MAX marks.
  2. If the engine coolant level is below MIN mark, add engine coolant.

Scheme 4

Scheme 4: ENGINE COOLANT PROTECTION INSPECTION
Scheme 4: ENGINE COOLANT PROTECTION INSPECTION
  1. Measure the coolant temperature and specific gravity with a thermometer and a hydrometer.
  2. Determine the coolant protection by referring to the graph shown. If the coolant protection is not proper, add water or coolant.

ENGINE COOLANT LEAKAGE INSPECTION

WARNINGNever remove the cooling system cap while the engine is running, or when the engine and radiator are hot. Scalding coolant and steam may shoot out and cause serious injury. It may also damage the engine and cooling system. Turn off the engine and wait until it is cool. Even then, be very careful when removing the cap. Wrap a thick cloth around it and slowly turn it counterclockwise 2.5 turns. Step back while the pressure escapes. When you are sure all the pressure is gone, turn the cap using the cloth, and remove it.

Scheme 5

Scheme 5
Scheme 5
  1. Inspect the engine coolant level.
  2. Remove the cooling system cap.
  3. Clean the installation parts of the cooling system cap and the upper radiator hose.
  4. Install the SST or aftermarket equivalent and a radiator cap tester to the coolant reserve tank filler port.
  5. Apply pressure using the radiator cap tester. Pressure 145 kPa {1.5 kgf/cm 2 , 21 psi} [1 min]
  6. When pressurizing the coolant reserve tank, verify that the pressure is maintained. If the gauge needle drops, it may indicate water leakage, therefore perform leakage inspection. If engine coolant leaks from the upper hose installation part, replace the upper hose and the clamp. If the engine coolant leaks from the main body of the radiator (caulked part), replace the radiator.

THERMOSTAT INSPECTION

  1. Inspect the thermostat for the following. The valve should not open under normal temperature. Opening temperature and valve lift. If there is malfunction, replace the thermostat.

COOLING FAN MOTOR COMPONENT INSPECTION

  1. Perform cooling fan control system inspection. (See COOLING FAN CONTROL SYSTEM INSPECTION .) If the cooling fan control does not operate properly, inspect the following: ECT sensor. A/C switch. A/C refrigerant pressure switch (High/low pressure). A/C refrigerant pressure switch (Middle pressure). VSS. A/C magnetic clutch. Fan control module power supply circuit. Fan control module GND circuit. Fan control signal circuit (between fan control module terminal B and PCM terminal 1W). If the all items are okay, replace cooling fan component.

Scheme 6

Scheme 6: RADIATOR DRAIN PLUG REPLACEMENT
Scheme 6: RADIATOR DRAIN PLUG REPLACEMENT
  1. Drain the engine coolant. (See «ENGINE COOLANT REPLACEMENT»(ref-177562-S03658227892005060200000) .)
  2. Loosen the radiator drain plug completely.
  3. Using a flathead screwdriver or equivalent, pry out the radiator drain plug.
  4. Install a new radiator drain plug with a new O-ring. Tightening Torque 1.2-1.5 N.m {13-15 kgf.cm, 11-13 in.lbf}
  5. Add engine coolant. (See «ENGINE COOLANT REPLACEMENT»(ref-177562-S03658227892005060200000) .)

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