VALVE CLEARANCE CHECK AND ADJUSTMENT <Except MIVEC>


note The valve clearance check and adjustment should be done when the engine is cold.
1.Remove the rocker cover.

2.
caution The crankshaft should always be turned in a clockwise direction.
Align the camshaft sprocket timing marks and set the No. 1 cylinder at compression stroke top dead centre.




3.For the portions with the arrows shown below, measure and adjust the valve clearances by using the following procedures.
(1) <Inlet side>
(2) By using special tool valve adjusting feeler gauge (MB992852), check that the clearance is within the standard value between the valve stem and adjusting screw.
Standard value (cold engine): 0.14 ± 0.03 mm
(3) If the valve clearance is not as specified, loosen the adjusting screw lock nut and adjust the clearance using special tool (MB992852) between the valve stem and the adjusting screw while turning the adjusting screw.
(4)
caution Pay special attention that the tightening torque is not beyond this valve. If the tightening torque is beyond the valve, the valve stem would possibly bend.
While holding the adjusting screw with a screwdriver to prevent it from turning, tighten the lock nut to the specified torque using special tool valve adjusting socket (MB991477).
Tightening torque: 9.0 ± 1.0 N·m
(5) <Exhaust side>
(6) By using the thickness gauge, measure the clearance between the cam and roller.
Standard value (cold engine): 0.16 ± 0.03 mm
(7) By using the thickness gauge, measure the clearance between the cam and roller.
(8)
caution Pay special attention that the tightening torque is not beyond this valve. If the tightening torque is beyond the valve, the valve stem would possibly bend.
While holding the adjusting screw with a screwdriver to prevent it from turning, tighten the lock nut to the specified torque using special tool valve adjusting socket (MB992046), valve adjusting socket.
Tightening torque: 9.8 ± 1.0 N·m
4.Turn the crankshaft 360° clockwise to bring No. 4 cylinder to the top dead centre position.

5.For the portions with the arrows shown below, measure and adjust the valve clearances by using the same procedures as ones in the Step 3.
6.Install the rocker cover.