Valve Clearance Inspection And Adjustment
Note. Inspect and adjust the valve clearance when the engine is cold (Engine coolant temperature : 20°C (68°F)) and cylinder head is installed on the cylinder block.
| WARNING | In case of removing the high pressure fuel pump, high pressure fuel pipe, delivery pipe, and injector, there may be injury caused by leakage of the high pressure fuel. So don't do any repair work right after engine stops. |
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- Remove the cylinder head cover. Refer to «TIMING SYSTEM»(ref-429611) .
- Set No. 1 cylinder to TDC/compression. Turn the crankshaft pulley and align its groove with the timing mark "T" of the lower timing chain cover. Check that the TDC marks (A) of the CVVT sprockets are in straight line on the cylinder head surface as shown in the illustration. If not, turn the crankshaft one revolution (360°)
- Inspect the valve clearance. Check only the valve indicated as shown. Measure the valve clearance. Using a thickness gauge, measure the clearance between the tappet and the base circle of camshaft. Record the out-of-specification valve clearance measurements. They will be used later to determine the required replacement adjusting tappet. Valve clearance Specification Engine coolant temperature : 20°C (68°F) Limit Intake : 0.10 ~ 0.30 mm (0.0039 ~ 0.0118 in.) Exhaust : 0.20 ~ 0.40 mm (0.0079 ~ 0.0157 in.) Turn the crankshaft pulley one revolution (360°) and align the groove with timing mark "T" of the lower timing chain cover. Check only valves indicated as shown. Measure the valve clearance.
- Adjust the intake and exhaust valve clearance. Set the No. 1 cylinder to the TDC/compression. Mark the timing chains (A) on the timing marks of the CVVT sprockets. Remove the front camshaft bearing cap. Turn the crankshaft pulley 15° clockwise. Remove the service hole bolt (A) of the timing chain cover. NOTE: The bolt must not be reused once it has been assembled. Release the ratchet of the timing chain tensioner by pulling the link down using a thin rod. Remove the exhaust camshaft bearing cap and exhaust camshaft. Remove the intake camshaft bearing cap and intake camshaft. CAUTION: When disconnect the timing chain from the CVVT sprocket, hold the timing chain. Tie down timing chain so that it doesn't move. NOTE: Be careful not to drop anything inside timing chain cover. Measure the thickness of the removed tappet using a micrometer. Calculate the thickness of a new tappet so that the valve clearance comes within the specified value. Valve clearance (Engine coolant temperature : 20°C (68°F)) 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 - 0.30 mm (0.0118 in.)) Select a new tappet with a thickness as close as possible to the calculated value. NOTE: Shims are available in 47 size increments of 0.015 mm (0.0006 in.) from 3.00 mm (0.118 in.) to 3.690 mm (0.1452 in.) Place a new tappet on the cylinder head. Hold the timing chain, and install the intake camshaft and CVVT assembly. Align the timing marks (A) on the timing chains and CVVT sprockets. Install the exhaust camshaft and CVVT assembly after releasing the ratchet of the timing chain tensioner. Install the front bearing cap. Install the service hole bolt. Tightening torque: 11.8 ~ 14.7 N.m (1.2 ~ 1.5 kgf.m, 8.7 ~ 10.8 lb-ft) Turn the crankshaft two turns in the operating direction (clockwise), and then check that the TDC marks (A) of the CVVT sprockets are in straight line on the cylinder head surface. Recheck the valve clearance. Valve clearance (Engine coolant temperature : 20°C (68°F)) (Specification) Intake : 0.17 ~ 0.23 mm (0.0067 ~ 0.0090 in.) Exhaust : 0.27 ~ 0.33 mm (0.0106 ~ 0.0129 in.)