Tools and Materials Needed:
1. Intake and Exhaust Valve Clearance Feeler Gauge
2. 10mm Socket and Wrench
3. Flat-Blade Screwdriver
4. Pliers
5. Spark Plug Socket or 5/8" Socket
6. Spark Plug Gap Gauge
Step-by-Step Instructions:
1. Preparations:
- Disconnect the negative terminal from your car's battery to ensure safety and prevent accidental electrical damage.
- Allow the engine to cool down completely to avoid burns and ensure precise valve adjustments.
2. Locate Valve Cover:
- Open your vehicle's hood and locate the valve cover, which is typically held by bolts.
3. Remove Valve Cover Bolts:
- Use the 10mm socket and wrench to remove the bolts securing the valve cover. Be cautious as some bolts might be hidden under plastic or rubber caps.
4. Remove Valve Cover:
- Gently lift and remove the valve cover to reveal the engine's camshafts and rocker arms.
5. Positioning the Crankshaft:
- Insert a flat-blade screwdriver into the crankshaft position sensor located near the front of the engine.
- Use the screwdriver to align the notch on the crankshaft pulley with the timing indicator on the engine's timing belt cover.
6. Valve Clearance Measurement:
- Check the valve clearances by inserting the feeler gauge between the valve stem and the rocker arm.
- The specifications for the intake valve clearance are generally 0.006 to 0.008 inches (0.15 to 0.20 mm), while the exhaust valve clearance is 0.010 to 0.012 inches (0.25 to 0.30 mm).
7. Adjust Valve Clearance (if needed):
- If any valve clearance is out of specification, use the 10mm wrench and a flat-blade screwdriver to loosen the locknut on the rocker arm.
- Adjust the valve clearance by turning the adjusting screw either clockwise (to decrease clearance) or counterclockwise (to increase clearance).
- Tighten the locknut after achieving the correct valve clearance.
8. Reinstall Valve Cover:
- Carefully place the valve cover back onto the engine and reinstall the bolts you removed earlier.
- Make sure the valve cover is securely fastened to prevent oil leaks.
9. Reconnect Battery Terminal:
- Connect the negative terminal back to your car's battery.
10. Start Engine and Verify:
- Start your car and let it run for a few minutes. Check for any unusual sounds or vibrations.
- If everything sounds and feels normal, you've successfully adjusted the valves on your 1995 Nissan 240SX.
Note:
- Valve adjustments should be carried out periodically as per your vehicle's service manual or when symptoms like rough idling or poor performance indicate an issue.
- If you're unsure or uncomfortable performing this maintenance yourself, it's recommended to seek the assistance of a professional mechanic.
