Mitsubishi Car 1999-05

Valve Lash (Clearance) Adjustment

Print



Click image to see an enlarged view

Fig. Valve adjustment positions: (A) when engine is on TDC of cylinder 1 and (B) when engine is on TDC of cylinder 4



Click image to see an enlarged view

Fig. Adjusting the valve clearance

The only engines that require periodic adjustment of the valves are the 1.5L engine in the 1990-95 Mirage and the 1.8L in the 1993-95 Mirage.


WARNING
Incorrect valve clearance will cause noisy and/or unsteady engine operation, reduced engine output, and possible engine damage. Check the valve clearances and adjust as required while the engine is hot.

  1. Warm the engine to operating temperature. Turn the engine OFF . Disconnect the negative battery cable.
  2.  
  3. Remove all spark plugs so engine can be easily turned by hand.
  4.  
  5. Remove the valve cover.
  6.  
  7. Turn the crankshaft clockwise until the notch on the pulley is aligned with the T mark on the timing belt lower cover. This brings both No. 1 and 4 cylinder pistons to Top Dead Center (TDC).
  8.  
  9. Wiggle the rocker arms on No. 1 and 4 cylinders up and down to determine which cylinder is at TDC on the compression stroke. Both rocker arms should move if the piston in that cylinder is at TDC on the compression stroke.
  10.  
  11. Measure the valve clearance with a feeler gauge. When the No. 1 piston is at TDC on the compression stroke, check No. 1 intake and exhaust; No. 2 intake and exhaust. Then turn the crankshaft clockwise 1 turn to bring No. 4 to TDC on its compression stroke. With No. 4 on TDC, compression stroke, check No. 2 exhaust and intake; and No. 4 intake and exhaust. Clearance is as follows:
  12.  

1990-92 1.5L engine:



Exhaust valve: 0.0098 in. (0.25mm)
 
Intake valve: 0.0059 in. (0.15mm)
 

1993-95 1.5L engine:



Exhaust valve: 0.0098 in. (0.25mm)
 
Intake valve: 0.008 in. (0.20mm) 1993-95 1.8L engine:
 
Exhaust valve: 0.012 in. (0.30mm)
 
Intake valve: 0.008 in. (0.20mm)
 

  1. If the valve clearance is out of specification, loosen the rocker arm locknut and adjust the clearance using a feeler gauge while turning the adjusting screw. When at specification, tighten the locknut. Be sure to hold the screw securely in place when tightening the locknut to prevent it from turning when tightening the locknut. Tightening torque of the locknut is as follows:
  2.  


    1.5L engine: 9-11 ft. lbs. (12-15 Nm)
     
    1.8L engine: 7 ft. lbs. (9 Nm)
     

  3. Recheck the clearance and readjust.
  4.  
  5. After adjusting the valves, install the valve cover and spark plugs, and connect the negative battery cable.
  6.  

Valve clearance is not adjustable on these vehicles.

2.4L (4g69) Engine




NOTE
Before adjusting the valves, check that the engine coolant temperature is between 176-203 degrees and all lights and accessories are off.

  1. Remove the ignition coils. Remove the valve cover.
  2.  
  3. Turn the crankshaft clockwise until the notch on the pulley is lined up with the -T- mark on the timing indicator.
  4.  
  5. Move the rocker arms on the number one and number four cylinders up and down, by hand to determine which cylinder has its piston at the TDC position on the compression stroke.
    NOTE
    If both intake and exhaust valve rocker arms have a valve lash, the piston in the cylinder corresponding to these rocker arms is at TDC on the compression stroke.

  6.  
  7. Valve clearance can be checked and adjusted on the rocker arms indicated by the white arrow, in the illustration, when the number one cylinder piston is at TDC on the compression stroke and on the rocker arms indicated by the black arrow, in the illustration, when the number four piston is at TDC on the compression stroke.

    Click image to see an enlarged view

    Fig. Valve adjustment-2.4L (4G69) Engine

  8.  
  9. Check the valve clearance.
  10.  
  11. If adjustment is required, loosen the rocker arm lock nut and adjust the clearance to specification, while turning the adjusting screw.
  12.  
  13. After adjustment, hold the adjusting screw with a screwdriver (to prevent it from turning) and tighten the locknut to 8 inch lbs.
  14.  
  15. Rotate the crankshaft 360 degrees to line up the notch on the crankshaft pulley with the -T- mark on the timing indicator.
  16.  
  17. Check the valve clearance.
  18.  
  19. If adjustment is required, loosen the rocker arm lock nut and adjust the clearance to specification, while turning the adjusting screw.
  20.  
  21. After adjustment, hold the adjusting screw with a screwdriver (to prevent it from turning) and tighten the locknut to 8 inch lbs.
  22.  
  23. Install the valve cover. Install the ignition coils.
  24.  

 
label.common.footer.alt.autozoneLogo