Mazda 3 Service Manual: Timing Chain Removal/Installation [Skyactiv G 2.0]

WARNING:

• A hot engine can cause severe burns. Turn off the engine and wait until it is cool before servicing.

CAUTION:

• If the camshaft is rotated with the timing chain removed and the piston at the top dead center position, the valve may contact the piston and the engine could be damaged. When rotating the camshaft with the timing chain removed, rotate it after lowering the piston from the top dead center position.

• When rotating the camshaft using a wrench on the cast hexagon, the wrench may contact the rocker arm and damage the rocker arm. When holding the camshaft on the cast hexagon, to prevent damage to the rocker arm, use the wrench at engine rear side as shown in the figure to secure a clearance between the cam.

  

  
  

NOTE:

• Width at the cast hexagon of the camshaft is 22—24 mm {0.87—0.94 in}.

  

  
  

1. Remove the battery cover..

2. Disconnect the negative battery cable..

3. Remove the plug hole plate..

4. Remove the coolant reserve tank with the hose still connected and set it out of the way..

5. Remove the cooler hose bracket bolt and set the cooler hose aside.

6. Remove the aerodynamic under cover No.2 and splash shield as a single unit..

7. Remove the drive belt..

8. Drain the engine oil..

9. Remove the oil pan..

10. Remove in the order indicated in the table.

11. Install in the reverse order of removal.

12. Refill with the specified type and amount of the engine oil..

13. Start the engine and inspect the following:

• Leakage of engine oil.

• Runout and contact of pulley and belt.

• Ignition timing, idle speed and idle mixture..

1	Plug hole plate bracket (See Plug Hole Plate Bracket Installation Note.)
2	Dipstick
3	Ignition coil/ion sensor (See IGNITION COIL/ION SENSOR REMOVAL/INSTALLATION [SKYACTIV-G 2.0].)
4	Cylinder head cover (See Cylinder Head Cover Removal Note.) (See Cylinder Head Cover Installation Note.)
5	Oil shower pipe (See Oil Shower Pipe Installation Note.)
6	Drive belt auto tensioner (See Drive Belt Auto Tensioner Installation Note.)
7	Water pump pulley (See Water Pump Pulley Removal Note.) (See Water Pump Pulley Installation Note.)
8	Crankshaft pulley lock bolt (See Crankshaft Pulley Lock Bolt Removal Note.) (See Crankshaft Pulley Lock Bolt Installation Note.)
9	Crankshaft pulley
10	Front oil seal (See FRONT OIL SEAL REPLACEMENT [SKYACTIV-G 2.0].)
11	No.3 engine mount (See No.3 Engine Mount Removal Note.) (See No.3 Engine Mount Installation Note.)
12	Electric variable valve timing motor/driver (See Electric Variable Valve Timing Motor/Driver Installation Note.)
13	Engine front cover (See Engine Front Cover Removal Note.) (See Engine Front Cover Installation Note.)
14	Chain tensioner (See Timing Chain Removal Note.) (See Timing Chain Installation Note.)
15	Tensioner arm (See Timing Chain Removal Note.) (See Timing Chain Installation Note.)
16	Chain guide (No.1) (See Timing Chain Removal Note.) (See Timing Chain Installation Note.)
17	Timing chain (See Timing Chain Removal Note.) (See Timing Chain Installation Note.)
18	Chain guide (No.2)
19	Crankshaft sprocket
20	Oil pump chain tensioner
21	Oil pump driven sprocket (See Oil Pump Driven Sprocket Removal Note.) (See Oil Pump Driven Sprocket Installation Note.)
22	Oil pump chain
23	Oil pump drive sprocket
24	Key

Cylinder Head Cover Removal Note

1. Disconnect the OCV connector.

2. Remove the wiring harness clips secured to the cylinder head cover, and set the wiring harness aside.

3. Disconnect the ventilation hose.

4. Remove the fuel hose from the clip and set it aside.

5. Disconnect the brake vacuum hose from the intake manifold and set it aside.

6. Remove the cylinder head cover.

Water Pump Pulley Removal Note

CAUTION:

• Be careful not to damage the belt groove and surface of the water pump pulley when using tools, otherwise it will cause wear, breakage, abnormal noise of the drive belt (stretch belt), damage to the pulley, and rust.

1. Align the water pump pulley hole with the water pump hole as shown in the figure.

2. Insert an appropriate bolt (length approx. 70 mm {2.8 in}

) into the water pump hole as shown in the figure, and lock the water pump pulley against rotation.

3. Remove the water pump pulley.

4. Remove the bolt used for locking the water pump pulley against rotation.

Crankshaft Pulley Lock Bolt Removal Note

CAUTION:

• To prevent damage to the crankshaft pulley, protect the crankshaft pulley with a clean cloth so that the bar part (205-072) of the SST

  does not contact the crankshaft pulley.

• To prevent damage to the engine front cover, be careful not to allow the tab part (49 B011 105) of the SST

  to get caught between the crankshaft pulley and the engine front cover.

1. Remove the nut shown in the figure and set the power steering pipe component aside.

2. Install the SST

to the crankshaft pulley, and lock the crankshaft against rotation.

3. Remove the crankshaft pulley lock bolt.

No.3 Engine Mount Removal Note

1. Install the SST

using part number 99794 1025

or an M10×1.25

, length 25 mm {0.98 in}

bolt as shown in the figure.

2. Install the SST

using the following procedures.

CAUTION:

• Refer to the SST instruction manual for the basic handing procedure.

NOTE:

• Install front feet No. 2 to the left and right front shafts of the SST

  .

a. Remove the air cleaner and the air hose as a single unit..

b. Set the coolant reserve tank hose bracket in a place which does not interfere with the servicing.

c. As shown in the figure, set the rear shafts of the SST

to the left and right shock absorber bolts.

d. Install front feet No.2 to the left/right front shaft of the SST

, then align the groove of the front shaft of the SST

with the folded up part of the vehicle as shown in the figure.

e. Adjust the height of the left and right side bars of the SST

so that they are leveled, then tighten each part.

f. Apply tension to the chain to hold the engine.

g. Remove the No.3 engine mount.

Engine Front Cover Removal Note

1. Set the ground cable and wiring harness bracket shown in the figure aside.

2. Remove the engine front cover installation bolts.

3. Using a screwdriver wrapped in a cloth, peel the sealant away a little at a time, and remove the engine front cover.

CAUTION:

• Do not apply excessive force to the screwdriver. Otherwise, the engine front cover could be damaged.

• Be careful not to scratch or damage the seal surface. Otherwise, it could cause oil leakage.

Timing Chain Removal Note

1. Rotate the crankshaft clockwise to align the timing marks and the key position as shown in the figure, and set cylinder No.1 at top dead center (TDC).

2. While moving the exhaust camshaft back and forth in the direction of the arrow using a wrench on the cast hexagon, press down the link plate of the timing chain tensioner using a precision screwdriver and release the plunger lock.

NOTE:

• When moving the exhaust camshaft back and forth, the timing chain pushes the plunger in the chain tensioner making it easier to operate the link plate.

3. Push back the plunger slowly in the direction shown in the figure with the link plate still pushed down.

4. Remove the screwdriver from the link plate with the plunger still pushed down.

5. Release the force slightly from the plunger, and move it back and forth 2—3 mm {0.08—0.11 in}

.

6. Insert a wire with an approx. diameter of 1.5 mm {0.059 in}

or a paper clip where the link plate hole and the tensioner body hole overlap to secure the link plate and lock the plunger.

7. Remove the chain tensioner, tensioner arm, and the chain guide (No.1).

8. Remove the timing chain.

Oil Pump Driven Sprocket Removal Note

1. Temporarily assemble the crankshaft pulley lock bolt, and lock the oil pump against rotation as shown in the figure.

2. Remove the oil pump driven sprocket.

3. Remove the temporarily assembled crankshaft pulley lock bolt.

Oil Pump Driven Sprocket Installation Note

1. Temporarily assemble the crankshaft pulley lock bolt, and lock the oil pump against rotation as shown in the figure.

2. Install the oil pump driven sprocket.

Tightening torque

• 20—30 N·m {2.1—3.0 kgf·m, 15—22 ft·lbf}

3. Remove the temporarily assembled crankshaft pulley lock bolt.

Timing Chain Installation Note

1. Verify that the timing marks and the key are aligned to the position shown in the figure.

• If they are not in the position shown in the figure, rotate the camshaft and crankshaft to set the cylinder No.1 top dead center (TDC).

2. Install the timing chain while aligning the marks on each sprocket and the timing chain as shown in the figure.

3. Install the chain guide (No.1).

4. Install the tensioner arm.

5. Install the chain tensioner.

6. After installing the chain tensioner, remove the installed wire or paper clip, and then apply tension to the timing chain.

• If a new chain tensioner is used, remove the installed stopper.

  

  
  

7. Verify that there is no looseness in the timing chain, and re-verify that each sprocket is in the specified location.

8. Rotate the crankshaft clockwise two turns and inspect the valve timing.

Engine Front Cover Installation Note

NOTE:

• For a new engine front cover, the positioning pins in the two locations shown in the figure project to the outside of the engine.

  

  
  

1. If the engine front cover is newly replaced, tap the positioning pins in the two locations to the seal surface side.

2. Remove oil, dirt, and sealant adhering to the engine front cover, cylinder head, and cylinder block.

3. When reusing an engine front cover installation bolts, remove sealant adhering to the bolts.

CAUTION:

• Apply the silicon sealant in a single, unbroken line.

• To prevent silicone sealant from hardening, adhere the engine front cover and the cylinder block firmly within 10 min. after applying silicone sealant. After adhering them, tighten the installation bolts immediately.

• If a bolt with sealant adhering to it is used, it could result in cracks in the cylinder head and cylinder block.

  

  
  

4. Apply silicone sealant to the engine front cover as shown in the figure.

Bead thickness

• A: 2—6 mm {0.1—0.2 in}

• B: 4—6 mm {0.16—0.23 in}

• C: 4—8 mm {0.2—0.3 in}

5. Apply silicone sealant to the areas shown in the figure.

CAUTION:

• Apply the silicone sealant so that it charges into the inside of the cylinder head gasket.

6. Install the engine front cover to the engine.

NOTE:

• Temporarily install an appropriate bolt to the drive belt auto tensioner installation bolt hole to prevent a silicone sealant adhesion malfunction in the drive belt auto tensioner installation bolt hole and to prevent a bolt mis-installation due to silicone sealant hardening.

7. Prepare an appropriate M8 X 1.25

bolt (length 40 mm {1.6 in}

).

8. Tighten the engine front cover installation bolts in the order shown in the figure.

Tightening torque

• 20—26 N·m {2.1—2.6 kgf·cm, 15—19 in·lbf}

9. Remove the bolt installed to the drive belt auto tensioner installation bolt hole when installing the drive belt auto tensioner.

10. Install the ground cable and wiring harness bracket shown in the figure.

Electric Variable Valve Timing Motor/Driver Installation Note

1. Install a new O-ring to the O-ring installation groove of the engine front cover.

CAUTION:

• To prevent damage to the electric variable valve timing motor/driver, do not apply excessive force (force of 100 N {10.2 kgf, 22.5 lbf} or more) to the shaded areas shown in the figure.

2. Install the electric variable valve timing motor/driver using the following procedures.

NOTE:

• The eccentric shaft on the electric variable valve timing actuator side can be rotated to the left and right.

  

  
  

• The electric variable valve timing motor/driver can be assembled with the joint groove of the eccentric shaft in any position, and it will not lead to vehicle damage or performance reduction.

a. Before installation, rotate the joint of the end of the electric variable valve timing motor so that it is aligned to the joint groove on the electric variable valve timing actuator side.

b. Engage the joint on the end of the electric variable valve timing motor with the joint groove on the electric variable valve timing actuator side.

c. Attach the seal surface.

d. Tighten the electric variable valve timing motor/driver installation bolts.

Tightening torque

• 20—26 N·m {2.1—2.6 kgf·m, 15—19 ft·lbf}

No.3 Engine Mount Installation Note

NOTE:

• If the No.3 engine mount nut is loosened, tighten the stud bolts for the No.3 engine mount bracket because they may loosen.

1. Tighten the No.3 engine mount stud bolts.

Tightening torque

• 7—13 N·m {72—132 kgf·cm, 62—115 in·lbf}

2. Install the No.3 engine mount and temporarily tighten the bolts and nuts.

3. Tighten the No.3 engine mount installation bolts and nuts in the order shown in the figure.

No.	Tightening torque
1	75—104 N·m {7.7—10 kgf·m, 56—76 ft·lbf}
2	71—93 N·m {7.3—9.4 kgf·m, 53—68 ft·lbf}

4. Remove the SST

.

Crankshaft Pulley Lock Bolt Installation Note

CAUTION:

• To prevent damage to the crankshaft pulley, protect the crankshaft pulley with a clean cloth so that the bar part (205-072) of the SST

  does not contact the crankshaft pulley.

• To prevent damage to the engine front cover, be careful not to allow the tab part (49 B011 105) of the SST

  to get caught between the crankshaft pulley and the engine front cover.

1. Install the SST

on the crankshaft pulley to lock the crankshaft against rotation.

2. Tighten the crankshaft pulley lock bolt in the order shown in the following two steps.

Tightening procedure

• Step 1: 90—110 N·m {9.2—11 kgf·m, 67—81 ft·lbf}

• Step 2: 55—65°

3. Install the power steering pipe component.

Water Pump Pulley Installation Note

CAUTION:

• Be careful not to damage the belt groove and surface of the water pump pulley when using tools, otherwise it will cause wear, breakage, abnormal noise of the drive belt (stretch belt), damage to the pulley, and rust.

1. Install the water pump pulley to the water pump and temporarily tighten the bolt.

2. Align the water pump pulley hole with the water pump hole as shown in the figure.

3. Insert an appropriate bolt (length 70 mm {2.8 in}

) into the water pump hole shown in the figure and lock the water pump pulley against rotation.

4. Completely tighten the water pump pulley bolt to the specified torque.

Tightening torque

• 8—11 N·m {82—112 kgf·cm, 71—97 in·lbf}

5. Remove the bolt used for locking the water pump pulley against rotation.

Drive Belt Auto Tensioner Installation Note

CAUTION:

• To allow the drive belt auto tensioner to function correctly, always bleed the air from the drive belt auto tensioner using the following procedure after assembling the drive belt auto tensioner.

1. Install the drive belt auto tensioner to the engine.

CAUTION:

• To prevent damage to the drive belt auto tensioner, do not apply excessive torque after the tensioner moves full-stroke.

2. Move the drive belt auto tensioner up and down at full-stroke three times.

NOTE:

• By moving the drive belt auto tensioner up and down full-stroke three times, the piston inside the tensioner moves to bleed the air.

Oil Shower Pipe Installation Note

1. Install the oil shower pipe in the order shown in the figure.

Tightening torque

Installation position	Tightening torque
1	9—12 N·m {92—122 kgf·cm, 80—106 in·lbf}
2, 3	8.0—9.0 N·m {82—91 kgf·cm, 71—79 in·lbf}

Cylinder Head Cover Installation Note

CAUTION:

• To assure the sealing performance of the cylinder head cover, be careful of the following:

• Verify that the cylinder head cover gasket is inserted into the cylinder head cover groove and install the cylinder head cover.

• Remove oil, dirt, and sealant from the seal surface.

• To prevent silicone sealant from hardening, adhere the cylinder head cover and the cylinder head firmly within 10 min. after applying silicone sealant. After adhering them, tighten the installation bolts immediately.

1. Insert a new cylinder head cover gasket into the cylinder head cover groove.

2. Apply silicone sealant to the areas shown in the figure.

3. Tighten the cylinder cover bolts in the order shown in the figure.

Tightening torque

• 4.5—7.0 N·m {46—71 kgf·cm, 40—61 in·lbf}

Plug Hole Plate Bracket Installation Note

1. Tighten the plug hole plate bracket installation nuts in the order shown in the figure.

Tightening torque

• 4.5—7.0 N·m {46—71 kgf·cm, 40—61 in·lbf}