Valve Clearance Adjustment

Valve Clearance Inspection and Adjustment

1. 1
   Remove the cylinder head cover. (Refer to Cylinder Head Assembly - Cylinder Head Cover)
2. 2
   Set the No. 1 cylinder to TDC/compression.

   1. Turn the crankshaft pulley and align its groove with the valve timing mark on the timing chain cover.

      

   2. Make sure the marks on the intake and exhaust CVVT sprockets are in a straight line on the cylinder head surface, as shown in the illustration. If not, turn the crankshaft one revolution (360°).

      

   3. Mark the timing chain links to match the timing marks on the CVVT sprockets with indelible marker.

      

3. 3
   Remove the exhaust oil control valve (OCV) adapter (A).

   

4. 4
   Inspect the valve clearance.

   1. Check only the intake valves of No. 1 and No. 2 cylinders and the exhaust valves of No. 1 and No. 3 cylinders for clearance.
      • Using a thickness gauge, measure the clearance between the lash adjuster and the camshaft base circle.

        

      • Record the valve clearance measurements that are out of specification. They will be used later to determine the required lash adjuster for adjustment.
      Valve Clearance Specification (engine coolant temperature: 20 °C [68°F]) Limit Intake: 0.17 ~ 0.23 mm (0.0067 ~ 0.0091 in.) Exhaust: 0.22 ~ 0.28 mm (0.0087 ~ 0.0110 in.)
   2. Turn the crankshaft pulley one full revolution (360° clockwise) and align its groove with the alignment mark on the timing chain cover.
   3. Check the intake valves of No. 3 and No. 4 cylinders and the exhaust valves of No. 2 and No. 4 cylinders for clearance.

      

5. 5
   Remove the engine mount support bracket.

   1. Place a jack under the oil pan.
   2. Disconnect the ground cable (A) and remove the engine mounting support bracket (B).

      

   3. Slightly raise the engine with a jack to create space for releasing the timing chain tensioner.
6. 6
   Adjust the intake and exhaust valve clearance.

   1. Remove the bolt (A) from the service hole in the timing chain cover.

      

   2. Lock the timing chain tensioner in the fully retracted position. Insert a pick tool into the service hole in the timing chain cover and lift the ratchet plate (A) on the left side of the tensioner so that the pawl (B, located inside the tensioner behind the ratchet plate) is raised.

      

      

   3. Remove the camshaft bearing caps (A) in the order shown below.

      

   4. With the pawl raised, ask an assistant to lift the exhaust CVVT and camshaft (A) to allow the tensioner plunger (B) to retract.

      

      

   5. When the tensioner plunger is fully retracted, lift the ratchet plate (A) on the left side again through the service hole in the chain cover to align the hole in the ratchet plate with the hole in the tensioner body behind the ratchet plate, then lock the tensioner by inserting a pick tool through the holes of the ratchet plate and tensioner body.

      

   6. Separate the exhaust camshaft (A) from the exhaust CVVT by removing the bolt.

      

   7. Remove the exhaust CVVT (A) from the timing chain.

      

   8. Remove the intake CVVT and camshaft (A).

      

      

   9. Remove the tappet(s) with out-of-specification valve clearance from the cylinder head.

      

   10. Using a micrometer, measure the thickness of the removed tappet.

       

   11. Calculate the thickness of the new tappet so that the valve clearance is within the specified value. Valve clearance (engine coolant temperature: 20 °C) T: Thickness of removed tappet. A: Measured valve clearance. N: Thickness of new tappet. Intake: N = T + [A - 0.20 mm (0.0079 in.)] Exhaust: N = T + [A - 0.25 mm (0.0098 in.)]
   12. Select a new tappet with a thickness as close as possible to the calculated value.
   13. Install the new tappet into the cylinder head.
   14. Install the intake CVVT and camshaft (A) with the alignment mark on the intake CVVT sprocket aligned with the mark (painted link) on the timing chain.

       

   15. Install the exhaust CVVT (A) with the alignment mark on the exhaust valve. Align the CVVT sprocket with the mark (painted link) on the timing chain.

       

   16. Install the exhaust camshaft (A) onto the exhaust CVVT.

       Tightening torque: 63.7 ~ 74 N·m

   17. Remove the pick tool from the service hole in the timing chain cover.

       

   18. Make sure that each alignment mark on the intake and exhaust CVVT sprockets is aligned, as shown in the illustration.

       

   19. Install the bolt (A) into the service hole in the timing chain cover.

       Tightening torque: 27.5 ~ 30 N·m

       

   20. Install the engine mount bracket.
       1. Connect the ground cable (A) and install the engine mounting support bracket (B). Tightening torque: Ground line bolt: 10.8 ~ 13.7 N·m Nut (C): 88.3 ~ 108 N·m Bolt (D) and nuts (E): 58.8 ~ 74 N·m

          

       2. Remove the jack from the oil pan.
   21. Install the camshaft bearing caps in the order shown below. Tightening torque: Step 1 M6 bolt: 5.9 N·m M8 bolt: 9.8 N·m Step 2 M6 bolts: 11.8 ~ 13.7 N·m M8 bolts: 18.6 ~ 23 N·m

       

   22. Rotate the crankshaft two revolutions in the normal direction of rotation (clockwise) and make sure that the alignment marks on the intake and exhaust CVVT sprockets are in a straight line on the cylinder head surface.

       

   23. Recheck the valve clearance. Valve clearance (engine coolant temperature: 20 °C) [Specification] Intake: 0.17 ~ 0.23 mm (0.0067 ~ 0.0091 in.) Exhaust: 0.22 ~ 0.28 mm (0.0087 ~ 0.0110 in.)
   24. Install the exhaust oil control valve (OCV) adapter (A).

       Tightening torque: 9.8 ~ 11.8 N·m

       

   25. Install the cylinder head cover. (Refer to Cylinder Head Assembly - "Cylinder Head Cover")