Valve Clearance: Testing and Inspection
INSPECTIONCheck valve clearance if applicable to the following cases:
Intake side:
^ At the removal and installation of VVEL ladder assembly or valve-related parts, or at the occurrence of malfunction (poor starting, idle malfunction, unusual noise) due to aged deterioration in valve clearance.
CAUTION:
Valve clearance check on the intake side is not required after replacing the VVEL ladder assembly & cylinder head assembly with a new one. (install new VVEL ladder assembly & cylinder head assembly in factory shipped condition because it is factory-adjusted and inspected.)
NOTE:
VVEL ladder assembly cannot be replaced as a single part, because it is machined together with cylinder head assembly.
Exhaust side:
^ At the removal, installation, and replacement of camshaft (EXH) or valve-related parts, or at the occurrence of malfunction (poor starting, idle malfunction, unusual noise) due to aged deterioration in valve clearance.
1. Remove rocker covers (bank 1 and bank 2).
2. Measure the valve clearance as follows:
^ Use the feeler gauge (commercial service tool) of curved-tip. This allows the feeler gauge to access the clearance between camshaft and valve lifter with ease.
Valve clearance: Refer to EM-139, "Camshaft". Valve Clearance
NOTE:
Be sure to note the following points when measuring valve clearance on the intake side.
^ Before measuring, check that the position of drive shaft nose is within the angle shown in the figure.
A: Bank 1
B: Feeler gauge (commercial service tool)
c: 45° (drive shaft nose angle)
D: View
<---: Insertion direction of feeler gauge on the bank 1
<---: Insertion direction of feeler gauge on the bank 2
^ Refer to the illustration for the insertion direction of the feeler gauge since the direction depends on the bank.
a. Set No. 1 cylinder at TDC of its compression stroke.
^ Rotate crankshaft pulley clockwise to align timing mark (grooved line without color) with timing indicator.
<---: Timing mark (grooved line without color)
^ Check that exhaust cam nose on No. 1 cylinder (engine front side of bank 1) is located as shown in the figure.
^ If not, turn crankshaft one revolution (360 degrees) and align as shown in the figure.
1: Camshaft (EXH) (bank 1)
<---: Engine front
^ By referring to the figure, measure the valve clearances at locations marked "x" as shown in the table below (locations indicated in the figure).
<---: Engine front
^ No. 1 cylinder at compression TDC
b. Rotate crankshaft 240° clockwise (when viewed from engine front) to align No. 3 cylinder at TDC its compression stroke.
NOTE:
Mark a position 240° (b) from a corner of the hexagonal part of crankshaft pulley mounting bolt as shown in the figure. Use the hexagonal part as a guide.
1: Crankshaft pulley
A: Paint mark
^ By referring to the figure, measure the valve clearances at locations marked "x" as shown in the table below (locations indicated in the figure).
<---: Engine front
^ No. 3 cylinder at compression TDC
c. Rotate crankshaft 240° clockwise (when viewed from engine front) to align No. 5 cylinder at TDC of compression stroke.
NOTE:
Mark a position 240° (b) from a corner of the hexagonal part of crankshaft pulley mounting bolt as shown in the figure. Use the hexagonal part as a guide.
1: Crankshaft pulley
A: Paint mark
^ By referring to the figure, measure the valve clearances at locations marked "x" as shown in the table below (locations indicated in the figure).
<---: Engine front
^ No. 5 cylinder at compression TDC
3. Perform adjustment or replacement if the measured value is out of the standard.
^ Refer to "CAMSHAFT (EXH) VALVE CLEARANCE ADJUSTMENT". (Exhaust side)
^ Replace VVEL ladder assembly & cylinder head assembly.
CAUTION:
Never adjust valve clearance on the intake side.
NOTE:
Since the valve lifter (INT) cannot be replaced by the piece, VVEL ladder assembly & cylinder head assembly replacement are required.