GM Storm/Spectrum 1985-1993 Repair Guide

Valve Springs

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REMOVAL & INSTALLATION



  1. Remove the cylinder head.
  2.  
  3. If not done already, remove the intake and exhaust manifolds.
  4.  
  5. For the SOHC engine, remove the rocker arms/shafts assemblies. Remove the camshaft and oil seal.
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When disassembling valve trains, parts of which are to be reused, make sure to keep all components labeled or arranged for installation in their original locations. Rocker arms and/or lifters (tappets) must be installed against the same contact surfaces from which they were removed. Store lifters with the camshaft side downward to keep their oil from draining.

  1. For the DOHC engine, uniformly remove the camshaft bearing cap fasteners and caps. Begin at the center bearing cap of the exhaust camshaft and work outward, then repeat for the intake camshaft. Remove the camshafts, selective shims and lifters. If necessary a magnet may ease lifter removal.
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  3. Support the head on suitable blocks with the cylinder side facing downward to facilitate valve removal.
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  5. Using J-8062, or an equivalent valve spring compressor, and for the DOHC engines, J-37979-A, or an equivalent compressor adapter, remove the valve split collars. With the collars removed, carefully release the spring tension, then remove the upper valve seat and the valve spring from the cylinder head.
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  7. Place the parts from each valve in a separate container, numbered and identified for the valve and cylinder.
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  9. Inspect the valve springs for damage or wear and replace as necessary. Check the free length and/or spring pressure.
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To install:
  1. Install the valve springs and upper valve seats. Then, using the removal/installation tool to compress the springs, install the valve split collars to the valves. Be careful not to depress the spring cap too far as it may cause seal and stem damage.
  2.  

Once the split collars are installed and the compressor tool removed, the valve stems should be tapped lightly several times to ensure that the collars are fully seated.

  1. For the DOHC engine, lubricate and install the lifters, camshafts and camshaft bearing caps in their proper locations.
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  3. For the SOHC engine, lubricate and install the camshaft. Oil and install the lifters and shims, then install the rocker arm/shaft assemblies into their original locations.
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  5. Install the intake and exhaust manifolds to the cylinder head, unless the cylinder head installation procedure includes these components.
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  7. Install the cylinder head to the vehicle.
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INSPECTION



See Figures 1, 2 and 3

  1. Check the springs for cracks or other damage.
  2.  
  3. Use a ruler to measure the height of each spring at 4 different locations. A bent spring must be replaced. You can also check the spring for squareness using a steel square and a flat surface. Stand the spring and square on end on the flat surface. Slide the spring up to the square, revolve the spring slowly and observe the space between the top coil of the spring and the square. If the space exceeds 0.039 in. (1mm), replace the spring.
  4.  
  5. Measure the free length of the spring using calipers or a suitable service tool:
    1. For the Spectrum, the free length of the valve springs should be approximately 1.9095 in. (48.5mm). The minimum allowable free height is 1.8504 in. (47mm).
    2.  
    3. For the Storm, SOHC engine, the free length of the valve springs should be approximately 1.73 in. (44.1mm) for intake valves or 1.76 in. (44.7mm) for exhaust valves. The spring must be replaced if the height is less than 1.67 in. (42.6mm) for intake valves or 1.70 in. (43.7mm) for exhaust valves.
    4.  

  6.  
  7. For the 1.5L Spectrum engine, check the springs for proper pressure at the specified spring lengths using a valve spring tester. First completely compress the spring 3 times, then measure the tension. The pressure should be 47 lbs. (21 Kg) @ 1.57 in. (39.85mm). Replace springs with insufficient tension.
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Click image to see an enlarged view

Fig. Fig. 1: Checking valve spring specifications



Click image to see an enlarged view

Fig. Fig. 2: When checking squareness of valve springs, make sure to hold the square level



Click image to see an enlarged view

Fig. Fig. 3: Checking valve spring free length

 
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