Diagnostic procedure
Mazda 6 Service Manual: Radiator
RADIATOR REMOVAL/INSTALLATION
1. Disconnect the negative battery cable.
2. Drain the engine coolant. (See ENGINE COOLANT REPLACEMENT.)
3. Remove the cooling fan. (See COOLING FAN REMOVAL/INSTALLATION.)
4. Remove the oil hose. (ATX)
5. Remove in the order indicated in the table.
6. Install in t ...
Mazda 6 Service Manual: Heater core inspection
1. Remove the A/C unit. (See A/C UNIT REMOVAL/INSTALLATION.)
2. Remove the heater core from the A/C unit.
3. Inspect for cracks, damage, and coolant leakage.
If any problems are found, replace the heater core.
4. Inspect for bent fins.
If any are bent, use a flathead screwdriver to stra ...