TIMING CHAIN REMOVAL/INSTALLATION [SKYACTIV-G 2.5T]

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Special Service Tool (SST)

1.  : Mazda SST number 2.  : Global SST number
1: 49 UN30 3050 2: 303–050   Engine lifting bracket		1: 49 C017 5A0 2: –   Engine support set		—

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. To prevent damage to the rocker arm when holding the camshaft on the cast hexagon, use a wrench on the rear side of the engine as shown in the figure to secure a clearance between the cam.

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Note

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

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1.  Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.)

2.  Remove the plug hole plate. (See PLUG HOLE PLATE REMOVAL/INSTALLATION [SKYACTIV-G 2.5T].)

3.  Remove the ignition coil/ion sensors. (See IGNITION COIL/ION SENSOR REMOVAL/INSTALLATION [SKYACTIV-G 2.5T].)

4.  Remove the front under cover No.2. (See FRONT UNDER COVER No.2 REMOVAL/INSTALLATION.)

5.  Remove the front splash shield (RH). (See FRONT SPLASH SHIELD REMOVAL/INSTALLATION.)

6.  Remove the drive belt. (See DRIVE BELT REMOVAL/INSTALLATION [SKYACTIV-G 2.5T].)

7.  Drain the engine oil. (See ENGINE OIL REPLACEMENT [SKYACTIV-G 2.5T].)

8.  Remove the oil pan. (See OIL PAN REMOVAL/INSTALLATION [SKYACTIV-G 2.5T].)

9.  Remove in the order indicated in the table.

10.  Install in the reverse order of removal.

11.  Refill with the specified type and amount of the engine oil. (See ENGINE OIL REPLACEMENT [SKYACTIV-G 2.5T].)

12.  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. (See ENGINE TUNE-UP [SKYACTIV-G 2.5T].)

Taiwan

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Except Taiwan

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Cylinder Head Cover Removal Note

1.  Disconnect the connectors and clips shown in the figure and set the wiring harness aside.

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2.  Disconnect the hoses shown in the figure and remove the purge solenoid bracket component.

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3.  Remove the bolts shown in the figure and remove the bracket.

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4.  Remove the bolts and clips shown in the figure and remove the wiring harness bracket.

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5.  Set the engine wiring harness aside using the following procedure:

(1)  Disconnect or remove the following parts.

Step 1

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1	Wiring harness clip
2	OCV connector
3	Wiring harness clip
4	Wiring harness clip
5	Wiring harness clip

Step 2

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1	Wiring harness clip
2	Fuel pressure sensor connector
3	High pressure fuel pump connector
4	Bolt
5	Camshaft position (CMP) sensor connector
6	Wiring harness clip

(2)  Set the engine wiring harness in a place which does not interfere with the servicing.

6.  Disconnect the hoses shown in the figure and remove the vacuum pipe component.

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7.  Disconnect the vacuum hose.

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8.  Disconnect the hose shown in the figure and set the air pipe component aside with the water hose still connected.

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9.  Remove the bolt shown in the figure and remove the wiring harness bracket.

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10.  Remove the air inlet pipe. (taiwan) (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [SKYACTIV-G 2.5T].)

11.  Disconnect the air intake hose shown in the figure. (taiwan)

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12.  Disconnect the breather hose shown in the figure. (except taiwan)

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13.  Remove the cylinder head cover.

No.3 Engine Mount Removal Note

1.  Remove the clip and bolt shown in the figure and set the ground cable aside.

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2.  Set the PCM component aside using the following procedure:

(1)  Remove the bolts and connector shown in the figure.

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(2)  Move the PCM component in the direction of the arrow shown in the figure and set it aside with the PCM connectors connected.

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3.  Remove the nut shown in the figure and set the cooler hose aside.

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4.  Disconnect the ground cable shown in the figure.

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5.  Disconnect the clip shown in the figure.

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6.  Remove the bolts and clip shown in the figure and set the wiring harness bracket aside.

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7.  Install the SST using part number 99794 1025 or an M10 x 1.25, length 25 mm {0.98 in} bolt as shown in the figure.

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Caution

•  Slots have been adopted for the No.3 engine mount installation holes. If the No.3 engine mount is deviated from the original position when installing the No.3 engine mount, engine noise or vibration could increase. Before removing the No.3 engine mount, place alignment marks on the No.3 engine mount and body so that they can be assembled to the same positions as before removal.

8.  Place alignment marks on the locations shown in the figure so that they can be assembled to the same positions as before removal.

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Note

•  Paint so that the No.3 engine mount is framed on the body side and the outline of the nut is framed on the No.3 engine mount side.

9.  Install the SST using the following procedures.

Caution

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

Note

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

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(1)  Protect the positions shown in the figure using tape.

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(2)  As shown in the figure, set the rear shafts of the SST to the left and right shock absorber nuts.

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(3)  As shown in the figure, set the front shafts of the SST to the left and right bolts.

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(4)  Adjust the height of the left and right side bars of the SST so that they are leveled, then tighten each part.

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(5)  Apply tension to the chain to hold the engine.

10.  Remove the No.3 engine mount.

Engine Front Cover Removal Note

1.  Remove the bolts shown in the figure and set the wiring harness bracket aside.

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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.

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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).

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Note

•  The timing mark of SKYACTIV-G 2.5T is not completely parallel with the upper surface of the cylinder head.

2.  Verify the chain tensioner shape and identify the chain tensioner type.

Note

•  Verifying the chain tensioner type is necessary because the following procedures may differ according to the type of tensioner.

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3.  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. (Chain tensioner type A)

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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.

4.  Push back the plunger slowly in the direction shown in the figure with the link plate still pushed down. (Chain tensioner type A)

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5.  Remove the screwdriver from the link plate with the plunger still pushed down. (Chain tensioner type A)

6.  Release the force slightly from the plunger, and move it back and forth 2—3 mm {0.08—0.11 in}. (Chain tensioner type A)

7.  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. (Chain tensioner type A)

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8.  Loosen the chain tensioner using the following procedure: (Chain tensioner type B)

(1)  Insert a metal rod (diameter approx. 1.4 mm {0.055 in}, length approx. 55 mm {2.2 in}) into the hole in the body of the chain tensioner.

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(2)  Press the resister ring and unlock the plunger.

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(3)  Press the timing chain in the direction of the arrow and press in the chain tensioner plunger to the position where the groove and body hole are aligned.

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(4)  With the plunger pressed in, further insert the metal rod set in (1) above.

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Note

•  The rod secures the plunger and releases the tension.

(5)  Loosen the power of the hand pressing the plunger and verify that the pressed-in rod does not move.

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

10.  Remove the timing chain.

Oil Pump Chain Removal Note

1.  Verify that the balancer shaft sprocket alignment mark and key are aligned to the positions shown in the figure.

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Note

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

2.  Slightly loosen the balancer shaft sprocket installation bolt using the following procedure:

Note

•  At this stage, only loosen the installation bolt, do not remove it. Remove the bolt after removing the oil pump chain tensioner.

•  The balancer unit is constructed such that the end of the balancer shaft (No.1) protrudes from the balancer unit case. The balancer shaft (No.1) can be locked against rotation by holding the end using a wrench.

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(1)  Lock the balancer shaft (No.1) against rotation as shown in the figure.

Caution

•  To prevent damage to the balancer unit, protect the end of the balancer shaft (No.1) with a cloth.

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(2)  Slightly loosen the balancer shaft sprocket installation bolt.

3.  Slightly loosen the oil pump driven sprocket installation bolt using the following procedure:

Note

•  At this stage, only loosen the installation bolt, do not remove it. Remove the bolt after removing the oil pump chain tensioner.

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

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(2)  Slightly loosen the oil pump driven sprocket installation bolt.

(3)  Remove the temporarily assembled crankshaft pulley lock bolt.

4.  Set a cloth wrapped flathead screwdriver in the gap between the oil pump drive sprocket and the oil pump chain as shown in the figure.

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5.  Move the screwdriver in the direction of the arrow and press the oil pump chain, and then press on the plunger of the oil pump chain tensioner.

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6.  Insert a wire with an approx. diameter of 1.4 mm {0.055 in} or a paper clip into the body hole of the oil pump chain tensioner with the plunger pressed.

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Note

•  The wire or paper clip secures the plunger, and the tension can be released.

7.  Remove the oil pump chain tensioner.

8.  Remove the oil pump chain and balancer shaft sprocket as a single unit.

9.  Remove the oil pump driven sprocket.

Oil Pump Chain Installation Note

1.  Verify that the key and knock pin are aligned to the positions shown in the figure.

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

2.  Temporarily assemble the oil pump driven sprocket.

3.  Temporarily tighten the oil pump driven sprocket installation bolt.

4.  Align the oil pump chain alignment mark with the balancer shaft sprocket alignment mark.

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5.  Install the oil pump chain and balancer shaft sprocket as a single unit while aligning the alignment marks on each sprocket and oil pump chain as shown in the figure.

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6.  Temporarily tighten the balancer shaft sprocket installation bolt.

7.  Install the oil pump chain tensioner.

Caution

•  At this stage, do not remove the wire or paper clip installed to the oil pump chain tensioner.

8.  Tighten the oil pump driven sprocket installation bolt using the following procedure:

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

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(2)  Tighten the oil pump driven sprocket installation bolt.

Tightening torque

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

Black bolt: 26—36 N·m {2.7—3.6 kgf·m, 20—26 ft·lbf}

(3)  Remove the temporarily assembled crankshaft pulley lock bolt.

9.  Tighten the balancer shaft sprocket installation bolt using the following procedure:

Note

•  The balancer unit is constructed such that the end of the balancer shaft (No.1) protrudes from the balancer unit case. The balancer shaft (No.1) can be locked against rotation by holding the end using a wrench.

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(1)  Lock the balancer shaft (No.1) against rotation as shown in the figure.

Caution

•  To prevent damage to the balancer unit, protect the end of the balancer shaft (No.1) with a cloth.

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(2)  Tighten the balancer shaft sprocket installation bolt.

52—58 N·m {5.4—5.9 kgf·m, 39—42 ft·lbf}

10.  Remove the wire or paper clip installed to the oil pump chain tensioner and apply tension to the oil pump chain.

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

Timing Chain Installation Note

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

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Note

•  The timing mark of SKYACTIV-G 2.5T is not parallel with the upper surface of the cylinder head.

•  If the timing marks and key position have deviated, align them to the positions shown in the figure.

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

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Note

•  A new timing chain has one alignment mark (yellow) on the timing chain. The position of the alignment mark differs depending on the combination of the crankshaft sprocket and the timing chain.

•  When installing the timing chain, install it at the position of the alignment mark indicating the combination of any type A, B, or C.

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. (Chain tensioner type A)

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

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7.  After installing the timing chain tensioner, remove the installed rod, and then apply tension to the timing chain. (Chain tensioner type B)

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

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

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

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Note

•  The timing mark of SKYACTIV-G 2.5T is not parallel with the upper surface of the cylinder head.

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.

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

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

Caution

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

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3.  Completely clean and remove oil, dirt, silicone sealant or other foreign matter that may be adhering to the engine front cover, cylinder head, and cylinder block.

Caution

•  If oil, dirt and silicone sealant remains on the silicone sealant application area, the silicone sealant will not seal which will cause oil leakage.

•  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.

4.  Apply silicone sealant (TB1217D or equivalent) to the engine front cover as shown in the figure.

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

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Caution

•  Apply the silicone sealant so that it goes into 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.

?  A bolt mis-installation due to silicone sealant hardening.

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7.  Prepare an appropriate M8 x 1.25 bolt (length 40 mm {1.6 in}).

Caution

•  For the number 10 bolt of the tightening order, install the bolts with new washer.

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

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

10.  Install the wiring harness bracket shown in the figure.

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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.

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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.

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•  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.

(1)  Before installation, rotate the joint on 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.

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(2)  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.

(3)  Attach the seal surface.

(4)  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

Caution

•  If the No.3 engine mount is deviated from the original position when installing the No.3 engine mount, engine noise or vibration could increase. When installing the No.3 engine mount, align the alignment mark placed during removal and install it to the original position.

Note

•  When replacing the No.3 engine mount, place a mark at the same position as the one placed before removal.

•  If the No.3 engine mount nut is loosened, tighten the engine front cover stud bolts because they may have loosened.

1.  Tighten the engine front cover stud bolts.

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2.  Temporarily tighten the No.3 engine mount installation bolts and nuts using the following procedure:

(1)  Align the alignment marks on the body side and No.3 engine mount, and temporarily tighten the bolts shown in the figure.

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(2)  Temporarily tighten the nuts shown in the figure while aligning the alignment marks of the No.3 engine mount and nuts.

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Note

•  If the alignment marks are not aligned, align the alignment marks while slightly moving the engine and temporarily tighten the nuts.

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

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4.  Remove the SST.

5.  Return the wiring harness bracket to its original position.

6.  Install the bolts and clip shown in the figure.

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7.  Connect the clip shown in the figure.

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8.  Install the ground cable shown in the figure.

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9.  Return the cooler hose that was set aside to its original position and tighten the nut.

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10.  Install the PCM component using the following procedure:

(1)  Return the PCM component that was set aside to its original position.

(2)  Temporarily tighten the bolt shown in the figure.

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(3)  Tighten the PCM component installation bolts in the order shown in the figure.

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Tightening torque

9—10 N·m {92—101 kgf·cm, 80—88 in·lbf}

(4)  Install the wiring harness protector and connector.

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11.  Install the ground cable shown in the figure.

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Oil Shower Pipe Installation Note

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

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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.

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

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4.  Connect the breather hose shown in the figure. (except taiwan)

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5.  Install the air intake hose shown in the figure. (taiwan)

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6.  Install in the reverse order of removal.