VALVE CLEARANCE CHECK AND ADJUSTMENT


note The inlet valve side has the inlet continuous variable valve lift system. The oil clearance between the arm and the shaft makes it difficult to measure the valve clearance with the usual feeler gauge. Therefore, use the dial gauge and check the amount of valve lift.
1.Let the engine be in cold state.
2.Turn the ignition switch to the "LOCK" (OFF) position.
3.Remove the rocker cover assembly (Refer to ).

4.Install the special tool magnet base plate (MB992854) to the upper face of the cylinder head at the inlet side.
note At that time, remove the injector connector and the fixed portion of the harness bracket so that the engine harness cannot interfere with the installation.
5.Install the special tool dial gauge extension (MD998913) to the dial gauge.
6.When installing the dial gauge to the magnet base plate, the dial gauge must have almost the same angle as the inlet valve has.

7.Rotate the crankshaft clockwise and align the timing mark of the rocker shaft holder with the one circular timing mark of the V.V.T. sprocket. Therefore, the No. 1 cylinder is set at the top dead centre on its compression stroke.
8.For the No. 1 cylinder inlet valve, check and adjust the valve clearance according to the following procedures.


9.
caution
  • Never loosen the five Torx bolts at the upper portions of the rocker arm and camshaft assembly.
  • Never loosen the minimum lift stopper.
  • When rotating the coupling, do not apply the torque more than 3 N·m to prevent the damage.
  • Do not forcibly push the worm wheel to the minimum lift stopper and the maximum lift stopper.
Slowly rotate the coupling clockwise. When lightly touching the worm wheel to the minimum lift stopper, stop the worm wheel at the position shown in the illustration.
note When rotating the coupling clockwise, the worm wheel should move in the minimum lift direction. When rotating the coupling anti-clockwise, the worm wheel should move in the maximum lift direction.
note When manually rotating the coupling, insert a 12-point socket (24 mm) into the position on the coupling approximately 5 mm away from the rocker shaft holder. Connect the mini torque wrench and slowly rotate them.

10.Set the dial gauge on the upper face of the valve spring retainer at the forward engine side. Set the dial gauge to 0.
note As shown in the illustration, prevent the measurement error caused by the tilted valve, install the rocker arm to the outside of the rocker arm.

11.
caution
  • When rotating the coupling, do not apply the torque more than 3 N·m to prevent the damage.
  • Do not forcibly push the worm wheel to the minimum lift stopper and the maximum lift stopper.
Slowly rotate the coupling. Place the worm wheel as shown in the illustration so that the centre of the worm wheel gear can engage with the worm shaft (at around the middle lift position).
note When rotating the coupling clockwise, the worm wheel should move in the minimum lift direction. When rotating the coupling anti-clockwise, the worm wheel should move in the maximum lift direction.


12.
caution
  • Straightly insert the feeler gauge in the vertical direction not to touch the rocker arm roller guide.
  • When inserting the feeler gauge too much, you cannot pull out the feeler gauge after the adjustment. Do not insert the feeler gauge by more than 5 mm.
Pushing the feeler gauge with 0.15 mm in thickness between the swing cam and the roller of the rocker arm, rotate the coupling clockwise. Rotate the worm wheel to the minimum lift side. Insert the feeler gauge top by approximately 5 mm.
note If the valve clearance is excessive caused by the loosened adjusting screw and also if the feeler gauge can easily be inserted, perform the adjustment according to the overhaul valve clearance adjustment procedures (Refer to GROUP 11D - Timing Chain - Inspection ).
note If not easily inserting the feeler gauge, you can insert the feeler gauge more easily by rotating the crankshaft clockwise 2 revolutions with pushing the feeler gauge.
caution Do not forcibly push the worm wheel to the minimum lift stopper.
13.Check the worm wheel stopping at the position, as shown in the illustration, lightly touching to the minimum lift stopper. Check that the feeler gauge is securely inserted.
14.Check that the dial gauge reading is within the standard value.
Standard value: -0.11 ± 0.03 mm
note By inserting the 0.15 mm feeler gauge, the 0.26 mm-stroke occurs at the rocker arm adjusting screw side. Therefore, the valve clearance at the inlet side can be calculated by the following calculating formula using the dial gauge reading.
Calculating formula:
    valve clearance = 0.26 mm + (dial gauge reading)
    <Example > If the dial gauge reading is -0.11 mm,
    valve clearance = 0.26 mm + (-0.11) = 0.15 mm
15.If the dial gauge reading is not within the standard value, perform the adjustment according to the following procedures.
16.Loosen the rocker arm lock nut at the forward engine side. Pull up the adjusting screw once. From the upper portion of the adjusting screw, sufficiently apply the engine oil between the lower adjusting screw end and the valve axis end so that the engine oil can be provided enough. And then, perform the adjustment by rotating the adjusting screw so that the dial gauge can read -0.11 mm.
17.After the adjustment, hold the driver to prevent the adjustment screw from rotating. Temporarily tighten the lock nut. Rotate the coupling anti-clockwise. Return the worm wheel to around the middle lift position. Pull out the feeler gauge.
18.For the valve at the backward engine side, check the valve clearance in the same procedure as that of the valve at the forward engine side. If the valve clearance is not within the standard value, perform the adjustment in the same procedure as that of the valve at the forward engine side.
19.After the adjustment, hold the driver to prevent the adjustment screw from rotating. Tighten the lock nut to the specified torque. And then, check that the dial gauge reading does not change.
Tightening torque: 9.0 ± 1.0 N·m
20.Check again the valve clearance at the forward engine side. If the valve clearance is not within the standard value, perform the adjustment in the same procedure as the first adjustment.
21.After the adjustment, hold the driver to prevent the adjustment screw from rotating. Tighten the lock nut to the specified torque. And then, check that the dial gauge reading does not change.
Specified torque: 9.0 ± 1.0 N·m
22.Rotate the coupling anti-clockwise. Return the worm wheel to around the middle lift position. Pull out the feeler gauge.
23.For the No. 2 cylinder inlet valve, check and adjust the valve clearance according to the procedures from Step 9 to Step 22.
24.For the No. 1 and No.3 cylinder exhaust valves, check and adjust the valve clearance according to the following procedures.
25.Insert the feeler gauge between the exhaust valve axis end and the adjusting screw. Measure the valve clearance.
Standard value: 0.20 ± 0.03 mm
26.If the valve clearance is not within the standard value, loosen the lock nut. Adjust the adjusting screw so that the valve clearance can be within the standard value.
27.After the adjustment, hold the driver to prevent the adjustment screw from rotating. Tighten the lock nut to the specified torque.
Tightening torque: 9.0 ± 1.0 N·m

28.Rotate the crankshaft clockwise once. Align the crankshaft pulley timing mark (notch) with the "T" mark of the timing chain case. Therefore, the No. 4 cylinder is set at the top dead centre on its compression stroke.
29.For the No. 3 cylinder inlet valve, check and adjust the valve clearance according to the procedures from Step 9 to Step 22.
30.For the No. 4 cylinder inlet valve, check and adjust the valve clearance according to the procedures from Step 9 to Step 22.
31.For the No. 2 and No. 4 cylinder exhaust valves, check and adjust the valve clearance according to the procedures from Step 25 to Step 27.
32.Remove the special tool and return the engine harness to the original state.
33.Install the rocker cover assembly (Refer to ).