Dodge Omni/Horizon/Rampage 1978-1989 Repair Guide

Valve Adjustment

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Valve adjustment is not required as a matter of routine maintenance on the 1.6L and 1.7L engines. It is, however, necessary to check the valve clearance periodically. The 1.6L engine is an overhead valve design with adjustable rocker arms. The 1.7L engine clearance is adjusted by substituting discs located at the top of the cam followers. The discs are available in 0.01 in. (0.05mm) increments from 0.12-0.17 in. (3.00-4.25mm). One disc is located in each cam follower. A special tool is required for the disc removal and installation. The 2.2L engine uses hydraulic valve lifters and does not require valve adjustment.

ADJUSTMENT
1.6L Engine

The valve clearance should be checked with the engine cold and the piston at TDC (top dead center) on the compression stroke. The valves should be checked in the firing order 1-3-4-2.



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Fig. Fig. 1 Valve adjustment locations on the 1.6L engine

  1. Remove the valve cover.
  2.  
  3. Turn the crankshaft and watch the movement of the exhaust valves. When one is closing (moving upward) continue turning slowly until the inlet valve on the same cylinder just begins to open. This is called the ""valve rocking" position. The piston in the opposite cylinder is then at TDC on the compression stroke, and its valve clearance can be checked and adjusted.
  4.  
  5. After checking both valve clearances, rotate the crankshaft one half turn, the next cylinder in the firing order should have its valves ""rocking" and the pared cylinder can be adjusted.
  6.  



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Fig. Fig. 2 To make an adjustment, loosen the locknut and turn the adjusting screw until the correct size feeler gauge is a sliding fit between the valve stem and the rocker arm

  1. To make an adjustment, loosen the locknut and turn the adjusting screw until the correct size feeler gauge is a sliding fit between the valve stem and the rocker arm. The cold clearance should be 0.01 in. (0.25mm) intake and 0.02 in. (0.35mm) exhaust.
  2.  
  3. When the correct clearance has been obtained, tighten the locknut securely while holding the adjusting screw.
  4.  
  5. Reinstall the valve cover.
  6.  

1.7L Engine

The valve should be checked with the engine warm and be checked in the firing order 1-3-4-2.

  1. Run the engine to normal operating temperature.
  2.  
  3. Remove the valve cover.
  4.  
  5. Use a socket wrench on the crankshaft pulley or bump the engine around until the camshaft lobes of No. 1 cylinder are positioned. Due to the design of the camshaft lobes, it is not necessary that the lobes be pointing directly away (perpendicular) to the adjusting disc.
  6.  


WARNING
Do not turn the engine using the camshaft pulley, and only turn the engine in the direction of normal rotation.



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Fig. Fig. 3 Use a socket wrench on the crankshaft pulley or bump the engine around until the camshaft lobes of No. 1 cylinder are positioned

  1. Using a feeler gauge, check the valve clearance between the camshaft lobe and the valve adjusting disc.
  2.  

Clearance should be 0.007-0.011 in. (0.20-0.30mm) intake and 0.015-0.019 in. (0.40-0.50mm) exhaust.



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Fig. Fig. 4 Valve adjusting discs are available in different thicknesses

  1. If the measure clearance is not as specified, the valve adjusting disc can be removed and replaced with another of the proper size to give the correct valve clearance.
  2.  
  3. To remove the disc:
  4.  
    1. Depress the cam follower with Tool L-4417. This tool is necessary to remove the disc without damaging the camshaft or cylinder head.
    2.  
    3. Remove the valve adjusting disc with special removal pliers.
    4.  
    5. Calculate the thickness of a new disc and install one of the proper size. Be sure the number indicating the thickness of the disc faces down when installed.
    6.  
    7. Recheck the valve clearance.
    8.  

  5. Recheck or adjust all other valves in the same manner.
  6.  


WARNING
When the camshaft is in position to check the valves of No. 1 cylinder, cylinders No. 3 and 4 can also be checked or adjusted. It is only necessary to turn the engine one time to position the camshaft to check No. 2 cylinder.

  1. Reinstall the camshaft cover.
  2.  

2.2L Engine

This engine has hydraulic valve lifter and no adjustment is required.

 
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