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Compression Inspection [H3T]

WARNING:
  • Hot engines and oil can cause severe burns. Be careful not to burn yourself during removal/installation of each component.
  • Fuel vapor is hazardous. It can very easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel.
  • Highly pressurized fuel may spray out if the fuel line is cut. Due to the following dangers occurring with a fuel spray, always complete the [Fuel Line Safety Procedure] to prevent the fuel from spraying.
    • Fuel may cause irritation if it comes in contact with skin and eyes.
    • If fuel ignites and causes a fire, it may lead to serious injury or death, and damage to property and facilities.
  1. Verify that the battery is fully charged. (See BATTERY INSPECTION .)
  2. Connect the M-MDS to the DLC-2.
  3. Warm up the engine to the normal operating temperature.
  4. Display the following PCM PIDs using the M-MDS data monitor function. (Refer to [PID/DATA MONITOR INSPECTION ] in the appropriate troubleshooting information ) (Refer to [PID/DATA MONITOR TABLE [PCM] ] in the appropriate troubleshooting information )
    • ENG_RPM (engine speed)
  5. Perform [Fuel Line Safety Procedure]. (See BEFORE SERVICE PRECAUTION [H3T] .)
  6. Remove the cowl grille cover assembly (Right Side). (See COWL GRILLE REMOVAL/INSTALLATION .)
  7. Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .)
  8. Open the capsule cover. (See CAPSULE COVER OPEN/CLOSE [H3T] ).
  9. Remove the following parts.
    1. Engine cover (See ENGINE COVER REMOVAL/INSTALLATION [H3T] .)
    2. Turbocharger air outlet pipe No. 1 component (See CYLINDER HEAD COVER REMOVAL/INSTALLATION [H3T] ).
    3. Ignition coil (See IGNITION COIL REMOVAL/INSTALLATION [H3T] .)
    4. Cowl grille cover assembly (Left Side) (See COWL GRILLE REMOVAL/INSTALLATION .)
    5. Windshield wiper arm and blade (See WINDSHIELD WIPER ARM AND BLADE REMOVAL/INSTALLATION (L.H.D). .)
    6. Cowl grille (See COWL GRILLE REMOVAL/INSTALLATION .)
    7. Side cowl grille (right side) (See COWL GRILLE REMOVAL/INSTALLATION .)
    8. Relay and fuse block upper cover (front) (See RELAY AND FUSE BLOCK REMOVAL/INSTALLATION .)
    9. Relay and fuse block upper cover (rear) (See RELAY AND FUSE BLOCK REMOVAL/INSTALLATION .)
    10. Sub relay (See RELAY LOCATION .)
    11. Spark plugs (See SPARK PLUG REMOVAL/INSTALLATION [H3T] .)
  10. Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .)
  11. Measure the compression pressure using the following procedure.
    1. Install the compression gauge to the spark plug hole.
    2. Fully depress the accelerator pedal.
      NOTE:
      • The cranking method is as follows.
        • When the ignition switch is pressed with the brake pedal depressed, cranking starts.
        • When the ignition switch is pressed during cranking, cranking stops.
    3. Crank the engine and measure the following values simultaneously.
      • Compression pressure
      • Engine speed

        Compression pressure 

        G16695105Courtesy of MAZDA MOTORS CORP.
        COMPONENT OPERATIONS

        Component no. Refer to
        1 Compression pressure value (kPa {kgf/cm2 , psi})
        2 Engine speed (rpm)
        3 Standard
        4 Minimum specification

        Standard: Refer to the graph.

        Minimum: Refer to the graph.

        Maximum difference between cylinders: 188 kPa {1.92 kgf/cm2 , 27.3 psi} [250 rpm]

    4. Perform Steps  1 to  3 for all cylinders.
    5. If the measured value is the threshold or less, or if there is a cylinder which exceeds the specified maximum difference between cylinders, add a small amount of engine oil through the spark plug hole and perform Steps  1 to  3.
      • If the pressure increases by adding the engine oil, the piston ring or the cylinder surface is worn, or they are damaged. Perform overhaul servicing.
      • If the pressure does not increase, valve seizure, valve attachment malfunction, or pressure leakage from the cylinder head gasket might be occurring. Perform overhaul servicing.
    6. If the measured value is high, it is possible that there is an error in the electric variable valve timing system.
  12. Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .)
  13. Remove the compression gauge.
  14. Install the following parts.
    1. Spark plugs (See SPARK PLUG REMOVAL/INSTALLATION [H3T] .)
    2. Sub relay (See RELAY LOCATION .)
    3. Fuel pump relay (See RELAY LOCATION .)
    4. Relay and fuse block upper cover (rear) (See RELAY AND FUSE BLOCK REMOVAL/INSTALLATION .)
    5. Relay and fuse block upper cover (front) (See RELAY AND FUSE BLOCK REMOVAL/INSTALLATION .)
    6. Side cowl grille (right side) (See COWL GRILLE REMOVAL/INSTALLATION .)
    7. Cowl grille (See COWL GRILLE REMOVAL/INSTALLATION .)
    8. Windshield wiper arm and blade (See WINDSHIELD WIPER ARM AND BLADE REMOVAL/INSTALLATION (L.H.D). .)
    9. Cowl grille cover assembly (Left Side) (See COWL GRILLE REMOVAL/INSTALLATION .)
    10. Ignition coil (See IGNITION COIL REMOVAL/INSTALLATION [H3T] .)
    11. Turbocharger air outlet pipe No. 1 component (See CYLINDER HEAD COVER REMOVAL/INSTALLATION [H3T] ).
    12. Engine cover (See ENGINE COVER REMOVAL/INSTALLATION [H3T] ).
  15. Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .)
  16. Using the M-MDS, perform a DTC inspection. (Refer to [DTC INSPECTION ] in the appropriate troubleshooting information )
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