• 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}.
1. Release the tension on the timing chain using the following procedure:
Note
• Release the tension on the timing chain by securing the timing chain tensioner arm through the service hole on the engine front cover.
(1) Rotate the crankshaft clockwise so that cylinder No.1 is positioned around before top dead center (TDC) as shown in the figure.
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Note
• With cylinder No.1 positioned around before top dead center (TDC), there is no large movement (rotation) of the exhaust camshaft when the timing chain is removed. Therefore, installation of the electric variable valve timing actuator to the camshaft will be easier. (If there is a large movement of the exhaust camshaft, installation of the electric variable valve timing actuator to the camshaft must be performed while loosening the chain by rotating the exhaust camshaft.)
(2) Remove the blind plugs (upper and lower) on the engine front cover service holes.
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(3) Insert an M6 bolt (35—60 mm {1.4—2.3 in} length with thread to the end) to the upper service hole and tighten it until it contacts the tensioner arm, then loosen it approx. 180 degrees (set the bolt so that it sits slightly in front of the tensioner arm).
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Note
• The bolt contacts the tensioner arm when it is inserted approx. 20 mm {0.79 in}.
• Hold the exhaust camshaft using a wrench on the cast hexagon and move it back and forth a few times as shown in the figure. This will drain the oil from the chain tensioner and make the following servicing easier.
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(4) Insert a precision screwdriver into the lower service hole.
(5) 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.
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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.
(6) With the plunger lock released, rotate the exhaust camshaft clockwise until the timing chain loosens.
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(7) With the chain loosened, tighten the M6 bolt in the upper service hole so that the bolt is inserted approx. 5 mm {0.2 in} additionally to secure the tensioner arm.
Note
• By rotating the exhaust camshaft clockwise, the timing chain pushes the tensioner arm and the rib position deviates. The entire tensioner arm can be secured by hooking the bolt onto the deviated rib.
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• If the bolt cannot be inserted approx. 5 mm {0.2 in}, the plunger lock of the chain tensioner may not release, or the chain may not loosen enough. Return the bolt to the original position and restart the procedure from Step (5).
(8) After securing the tensioner arm, remove the chain guide (No.1).
Electric Variable Valve Timing Actuator Removal Note
Caution
• Keep the timing chain pulled up during and after the work in which it has been set aside from the sprocket. If the chain falls down, it may disengage from the sprocket on the crankshaft side and deviate, leading to valve timing deviation.
• After servicing, always verify the valve timing.
1. Mark the timing chain and each actuator so that they can be reassembled in the same condition as before removal.
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2. Hold the intake camshaft using a wrench on the cast hexagon and remove the electric variable valve timing actuator installation bolt.
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3. Using a screwdriver wrapped in a clean cloth, lightly press the electric variable valve timing actuator to the front and separate the intake camshaft and the actuator.
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4. Remove the timing chain from the exhaust and intake camshaft sprockets and set is aside, and remove the electric variable valve timing actuator.
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5. Return the timing chain to the exhaust camshaft sprocket, and pull the timing chain up and suspend it using a rope as shown in the figure.
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Camshaft Removal Note
Caution
• Keep the timing chain pulled up during and after the work in which it has been set aside from the sprocket. If the chain falls down, it may disengage from the sprocket on the crankshaft side and deviate, leading to valve timing deviation.
• After servicing, always verify the valve timing.
Note
• Remove the exhaust camshaft and the hydraulic variable valve timing actuator as a single unit.
1. Leave the timing chain as it is, which was suspended after electric variable valve timing actuator removal.
2. Temporarily install the cylinder head cover bolt to the position shown in the figure to use it for suspending the timing chain.
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3. Loosen the camshaft cap bolts in two or three passes in the order shown in the figure, and remove the camshaft caps.
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4. Remove the intake camshaft.
5. While setting the timing chain aside, remove the hydraulic variable valve timing actuator and the exhaust camshaft as a single unit.
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6. Pull up the timing chain and suspend it using a rope as shown in the figure.
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Rocker Arm Removal Note
1. Keep the rocker arms in the order of removal to enable reassembly in their original positions.
HLA, Switchable HLA Removal Note
1. Keep the HLAs and switchable HLAs in the order of removal to enable reassembly in their original positions.
HLA, Switchable HLA Installation Note
1. Perform air bleeding of the HLA and switchable HLA using the following procedure.
(1) Put the HLA and switchable HLA in a container filled with engine oil.
Caution
• Do not insert the round bar firmly because the check ball spring force is extremely weak.
(2) While lightly pressing the check ball using a round bar (approx. 1.0 mm {0.039 in} diameter), bleed air by moving the plunger up and down.
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(3) Press the end of the plunger in the oil and verify that there is no rebounding feel.
• If rebounding feel cannot be eliminated, replace the HLA and switchable HLA.
2. Visually inspect the HLA and switchable HLA surface where it contacts the rocker arm for wear or damage.
• If there is any malfunction, replace the HLA and switchable HLA.
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3. Assemble the HLAs to their original positions.
Caution
• Assemble the switchable HLAs correctly. Otherwise, the engine could be damaged.
4. Assemble the switchable HLAs to their original positions using the following procedure.
(1) Insert the switchable HLA into the cylinder head.
Note
• Assemble the lock pin of the switchable HLA so that it is inserted into the holes for locking on the cylinder head side.
• If area A in the figure is inserted into the switchable HLA with it facing the valve, it will facilitate insertion of the lock pin of the switchable HLA into the hole for locking on the cylinder head side.
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(2) Rotate the switchable HLA and verify that the lock pin of the switchable HLA is securely inserted into the hole for locking on the cylinder head side.
Note
• When the lock pin of the switchable HLA is securely inserted into the hole for locking on the cylinder head side, the switchable HLA cannot be rotated 90 degrees or more.
Rocker Arm Installation Note
1. Apply engine oil to the HLAs, switchable HLAs and the end of the valve stems.
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2. Install the rocker arms to the same positions as before removal.
Camshaft Installation Note
1. Apply SAE 90 gear oil or equivalent, or engine oil to the positions shown in the figure.
Caution
• Apply 0.05 ml {0.05 cc, 0.003 in3} or less of oil to area A in the figure.
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2. Apply gear oil (SAE 90 or equivalent) or engine oil to the thrust surface (both surfaces front and back) of the front journal on each camshaft.
Note
• If oil is applied to the front camshaft cap, oil should not be applied to the thrust surface of the front journal.
3. As shown in the figure, align the cam position of cylinder No.1 around top dead center (TDC) and place the intake camshaft on the cylinder head.
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4. Remove the rope suspending the timing chain on the exhaust side.
5. While aligning the mark on the timing chain placed during removal with the one on the hydraulic variable valve timing actuator, place the exhaust camshaft component on the cylinder head.
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6. Apply SAE 90 gear oil or equivalent, or engine oil to the central area of each journal on the camshaft.
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7. Apply SAE 90 gear oil or equivalent, or engine oil to the thrust surface of the front camshaft cap.
Note
• If oil is applied to the front journal thrust surface of each camshaft, oil should not be applied to the front camshaft cap.
8. Apply sealant (LOCTITE 962T, 518, 272 or equivalent) to the rear camshaft cap installation area on the exhaust side of the cylinder head or the rear camshaft cap on the exhaust side.
Note
• To prevent engine oil leakage, apply sealant to the rear camshaft cap installation area on the exhaust side of the cylinder head or the rear camshaft cap on the exhaust side, and seal the journal.
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Caution
• Do not spill sealant on the journal.
Sealant agent bead width
1—3 mm {0.04—0.11 in}
9. Install the camshaft caps in the marked number order, and temporarily tighten the camshaft cap installation bolts in two or three passes evenly.
10. Tighten the camshaft cap installation bolts in two steps in the order shown in the figure.
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Electric Variable Valve Timing Actuator Installation Note
1. Remove the rope suspending the timing chain on the intake side.
2. Remove the timing chain from the exhaust and intake camshaft sprockets and set it aside to the rear, then insert the electric variable valve timing actuator between the engine front cover and the cylinder head.
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3. Return the timing chain to the exhaust camshaft sprocket.
4. While aligning the mark on the timing chain placed during removal with the one on the electric variable valve timing actuator, engage the chain with the sprocket.
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5. Align the knock pin on the end of the intake camshaft with the notch on the actuator side, then assemble the actuator.
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Note
• Adjust the knock pin with the notch while adjusting the knock pin position by rotating the camshaft.
6. Hold the intake camshaft using a wrench on the cast hexagon, and tighten the electric variable valve timing actuator installation bolt.
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Timing Chain Installation Note
1. Install the chain guide (No.1).
2. Remove the bolt securing the tensioner arm and apply tension to the timing chain.
3. Inspect the timing chain for looseness.
4. Verify that the alignment marks on each sprocket and the timing chain are aligned.
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Note
• The timing mark is not parallel with the upper surface of the cylinder head.
5. Install the blind plugs (upper and lower) for the engine front cover service holes.
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Oil Shower Pipe Installation Note
1. Temporarily tighten the oil shower pipe installation bolts.
2. Install the oil shower pipe in the order shown in the figure.
