Note
Front Drive Belt
Verify that the drive belt auto tensioner indicator mark does not exceeds the limit.

Drive belt
Drive belt replacementMazda 6 Service Manual: Noise filter inspection
Brake Light Noise Filter
1. Inspect for resistance and continuity between the noise filter terminals
using an ohmmeter.
If not as specified, replace the noise filter.
Rear Window Defroster Noise Filter
Inspect for resistance and continuity between the noise filter terminals
using an ...
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 ...