If the filter is clogged, replace the engine oil and engine oil filter.
2. If the filter is not clogged, press the VTEC solenoid valve with your finger to check its ability to move.
If the VTEC solenoid is OK, check the engine oil pressure.
VTEC rocker arms
External inspection (engines D16Y8, D15Z6, D16Y5, A16I6, D15Z7).
1. Set the piston of the first cylinder to TDC.
2. Remove the cylinder head cover.
3. Use your hand to press on the middle rocker arm of the intake valve of the first cylinder.
4. Check the independent movement of the intake valve center rocker arm from the primary and secondary rocker arms.
Secondary rocker arm (shake)
5. Check the middle rocker arm of the intake valve of each cylinder in the piston position at TDC.
If the intake valve center rocker arm does not move, replace the center, primary and secondary rocker arms as an assembly and check that the pistons in the center and primary rocker arms move smoothly.
Replace the intake valve rocker arms as an assembly if any faults are found.
Inspection using a special tool (engine D16Y8, D15Z6, D16Y5, D16Y6, D15Z7)
Caution: Before using the special tool, make sure the pressure gauge on the air compressor shows a value greater than 400 kPa (4 kgf/cmg). Check the valve clearances before inspecting the operation of the rocker arms.
To protect the timing belt, cover it with a rag.
Check the middle rocker arm of the intake valve in the position of the piston of each cylinder at TDC.
1. Remove the cylinder head cover.
2. Close the discharge hole using a special tool.
3. Remove the sealing bolt from the inspection hole and attach the special tool to check the valve operation.
Inspection hole
4-1. (engines D16Y8 and D15Z7) Apply nominal pressure to the rocker arm synchronizing piston, then loosen the valve operation tester adjustment valve.
- Nominal pressure: 250kPa (2.5 kgf/cm²)
4-2. (engines D15Z6, D16Y5, D16Y6) Apply rated pressure to the intake valve rocker arm timing piston, then loosen the valve checker adjustment valve.
- Nominal pressure: 250 kPa (2.5 kgf/cm²)
5-1. (engine D16Y8) Make sure the primary and secondary rocker arms are mechanically connected by the piston and that the middle rocker arm does not move when pressed.
If the center rocker arms move independently of the primary and secondary rocker arms, replace the rocker arms as a set.
5-2. (engines D15Z6, D16Y5, D16Y6) The supplied nominal air pressure presses on the time adjustment plate; the synchronizing valve operates and connects the secondary rocker arm of the intake valve. Visually check the connection of the synchronizing piston.
Note: The timing piston can be seen in the gap between the secondary and primary rocker arms. When the timing plate engages with notch A on the timing piston, the piston will be locked in the extended position.
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6-1. (engines D15Z6, D16Y5, D16Y6, D15Z7) Stop the air supply and press the timing adjustment plate; the synchronizing piston will return to its initial position with a click. Visually check the disconnection of the synchronizing pistons.
Note: When the timing plate is compressed, it causes the timing piston to disengage, allowing the timing piston to return to its original position under the action of the spring.
Replace the intake valve rocker arms as an assembly if any fault is found.
7-1. (engines D16Y8, D15Z8, D18Y5, D16Y6) Remove special tools.
7-2. (engine D15Z7) Remove the special tools and tighten the plug.
8. (engine D15Z7) Remove the plug from the B test hole and attach the valve inspection tool.
9. (engine D15Z7) After loosening the control valve on the valve control device, apply the required air pressure according to technical requirements to the A7B holes of the inlet valve rocker arm synchronizing piston.
- Air pressure according to technical requirements: 250 kPa (2.5 kgf/cm²)
10. (engine D15Z7) Make sure that the primary and secondary intake rocker arms are mechanically connected by the piston and that the secondary rocker arm does not turn when pressed with your finger.
If the intake valve center rocker arm turns independently of the primary and secondary rocker arms, replace the rocker arms as a set.
11. (engine D15Z7) Remove the special tool, then tighten the plug.
12. (engines D16Y8, D15Z7) Using a 10mm rod, push each return device through its full stroke. Replace any return device that does not move smoothly.
13. After inspection, make sure that the malfunction indicator lamp does not light.
[Information obtained from this source: hondabook]