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.
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- Remove the engine cover.
- Remove the engine side cover.
- Remove air cleaner assembly.
- Remove the surge tank. Refer to «INTAKE AND EXHAUST SYSTEM»(ref-584173) .
- Remove the cylinder head cover. Refer to «TIMING SYSTEM»(ref-584174) .
- Set No. 1 cylinder to TDC/compression. Turn the crankshaft pulley clockwise and align its groove with the timing mark "T" of the lower timing chain cover. Check that the mark (A) of the camshaft timing sprockets are in straight line on the cylinder head surface as shown in the illustration. If not, turn the crankshaft clockwise one revolution (360°). NOTE: Do not rotate engine counterclockwise.
- Inspect the valve clearance. With No. 1 cylinder at TDC inspect clearances only on the valves shown in diagram below. Measurement method. 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 : 0.17 ~ 0.23 mm (0.0067 ~ 0.0090 in.) Exhaust : 0.27 ~ 0.33 mm (0.0106 ~ 0.0129 in.) Turn the crankshaft pulley clockwise one revolution (360°) and align the groove with timing mark "T" of the lower timing chain cover. With No. 4 cylinder at TDC inspect clearances only the valves shown in diagram below. Refer to procedure step 1 .
- Adjust the intake and exhaust valve clearance. Set the No. 1 cylinder to the TDC/compression. Remove the timing chain. NOTE: Before removing the timing chain, mark the RH/LH timing chain with an identification based on the location of the sprocket because the identification mark on the chain for TDC (Top Dead Center) can be erased. Remove the LH/RH exhaust camshaft OCV (A). Remove the LH/RH camshaft bearing cap (A) and thrust bearing cap (B). Remove the LH/RH camshaft assembly (A). Remove the tappets. 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. 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 41 size increments of 0.015 mm (0.0006 in.) from 3.00 mm (0.118 in.) to 3.600 mm (0.1417 in.) Place a new tappet on the cylinder head. NOTE: Apply engine oil at the selected tappet on the side and top surface. Install the intake and exhaust camshaft. Install the bearing caps. Refer to «REASSEMBLY»(ref-584175-S42323941232013110100000) . Install the timing chain. Refer to «INSTALLATION»(ref-584174-S23566767792013110100000) . Turn the crankshaft two turns in the operating direction (clockwise) and realign crankshaft sprocket and camshaft sprocket timing marks (A). 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.)