Mazda 2: Variable Valve Timing Actuator

VARIABLE VALVE TIMING ACTUATOR INSPECTION

CAUTION:

• The variable valve timing actuator cannot be disassembled since it is a precision unit.

1. Disconnect the negative battery cable.

2. Remove the fresh-air duct and the air cleaner as a single unit. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION).

3. Remove the ignition coils. (See IGNITION COIL REMOVAL/INSTALLATION).

4. Disconnect the ventilation hose. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION).

5. Set the vacuum hose out of the way.

6. Remove the cylinder head cover. (See TIMING CHAIN REMOVAL/INSTALLATION).

7. Verify that the camshaft knock pin hole of the variable valve timing actuator and the T-mark of the cover are aligned and fixed as shown in the figure.

• If the camshaft knock pin hole and the T-mark of the cover do not align, rotate the crankshaft two times in the direction the engine rotates, and then verify that they are aligned.
  • If it does not align, replace the variable valve timing actuator.
• If under any condition the variable valve timing actuator makes a hitting noise directly after the camshaft exceeds maximum lift while rotating the crankshaft two times in the direction of engine rotation, replace the variable valve timing actuator as it has not been fixed.

8. Install in the reverse order of removal.

VARIABLE VALVE TIMING ACTUATOR REMOVAL/INSTALLATION

CAUTION:

• Remove the variable valve timing actuator as a single unit with the camshaft sprocket.

1. Disconnect the negative battery cable.

2. Remove the fresh-air duct and the air cleaner as a single unit. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION).

3. Remove the ignition coils. (See IGNITION COIL REMOVAL/INSTALLATION).

4. Disconnect the ventilation hose. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION).

5. Set the vacuum hose out of the way.

6. Remove the cylinder head cover. (See TIMING CHAIN REMOVAL/INSTALLATION).

7. Remove the drive belt. (See DRIVE BELT REMOVAL/INSTALLATION).

8. Remove the engine front cover blind plug as shown in the figure.

9. Insert a M6 bolt (45 to 80 mm length bolt with threads to the end) into the right-side service hole shown in the figure, and set the bolt at a slightly outward position by loosening it approx. 2 mm from where it contacts the tensioner arm.

10. Release tension on the timing chain.

NOTE:

• When the crankshaft pulley is turned counterclockwise, the timing chain loosens because the tensioner arm is pressed by the timing chain and the plunger of the chain tensioner is pressed in.

• When the timing chain loosens, the tensioner arm moves to the position shown in the figure and presses the M6 bolt in, which secures the tensioner arm.

1. Press down the link plate of the chain tensioner from the service hole on the left side using a thin flathead screwdriver (precision screwdriver) as shown in the figure. Then rotate the crank pulley backwards (counterclockwise) with the plunger lock released.

2. Rotate the M6 bolt installed to the front cover by hand and insert it to the position where it catches the inside of the rib on the tensioner arm.

11. Fix the camshaft using a wrench on the cast hexagon. Remove the camshaft sprocket installation bolt.

12. Remove the timing sprocket on the exhaust side with the timing chain positioned out of the way.

13. Loosen the camshaft cap installation bolts in two or three steps in the order shown in the figure, and remove the camshaft caps.

14. Remove the variable valve timing actuator and intake camshaft as a single unit.

15. Lock the camshaft against rotation by holding the camshaft with the vise and securing the cast hexagon with a wrench.

16. Loosen the variable valve timing actuator installation bolt, and then remove the variable valve timing actuator.

17. Install the variable valve timing actuator.

18. Tighten the variable valve timing actuator installation bolt.

Tightening torque

• 50-60 N*m {5.1-6.1 kgf*m, 37-44 ft*lbf}

19. Align the timing marks on the crank pulley and the front cover, and then align the No.1 cylinder to the TDC.

20. With No.1 cylinder cam aligned at TDC of the compression stroke, install the variable valve timing actuator and the camshaft on the intake air side as a single unit.

21. Install the camshaft caps to the position of a carved seal number to shown in the figure, and tighten the camshaft installation bolts in two or three steps uniformly in the order shown in the figure.

Tightening torque

• 12-14 N*m {116-145 kgf*cm, 100-125 in*lbf}

22. Align the sprocket timing marks on the intake and exhaust camshafts so that they form a straight line in alignment with the upper horizontal surface of the cylinder head.

23. Fix the camshaft using a wrench on the cast hexagon. Install the camshaft sprocket installation bolt.

Tightening torque

• 50-60 N*m {5.1-6.1 kgf*m, 37-44 ft*lbf}

24. Remove the M6 bolt holding the tensioner arm.

25. Verify that there is no slack in the timing chain, and then verify that the marks on the camshaft sprocket and the crank pulley are aligned.

26. Inspect the valve timing by rotating the crankshaft clockwise twice.

27. Install the new engine front cover blind plug.

Tightening torque

• 3.0-6.0 N*m {31-61 kgf*cm, 27-53 in*lbf}

28. Install in the reverse order of removal.

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