Chevrolet Citation/Omega/Phoenix/Skylark 1980-1985 Repair Guide

Cylinder Head

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REMOVAL & INSTALLATION



The engine should be "overnight" cold before removing the cylinder head. On fuel injected engines, relieve the pressure in the fuel system before disconnecting any fuel line connections. See under Electric Fuel Pump.

Four Cylinder


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Fig. Fig. 1 Cylinder head mounting-4-cylinder engine



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Fig. Fig. 2 When removing the cylinder head, unbolt and position the A/C compressor aside



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Fig. Fig. 3 Tag and detach all the necessary electrical connections



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Fig. Fig. 4 Unfasten the retaining clamp, then disconnect the upper radiator hose



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Fig. Fig. 5 Tag and disconnect the spark plug wires from the plugs



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Fig. Fig. 6 Use the proper size ratchet and socket combination to loosen the spark plug ...



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Fig. Fig. 7 ... then remove the spark plug from the cylinder head



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Fig. Fig. 8 Unfasten the rocker arm (valve) cover retaining bolts ...



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Fig. Fig. 9 ... then remove the rocker arm (valve) cover from the cylinder head



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Fig. Fig. 10 After unfastening the retaining bolt, remove the rocker arms ...



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Fig. Fig. 11 ... then remove the pushrods, keeping all the parts in order for installation



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Fig. Fig. 12 After removal, place the pushrods in a holder designed to keep them in order for installation



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Fig. Fig. 13 Be sure to remove both the inner ...



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Fig. Fig. 14 ... and outer row of cylinder head bolts



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Fig. Fig. 15 Lift the cylinder head off of the cylinder block



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Fig. Fig. 16 Remove and discard the old cylinder head gasket



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Fig. Fig. 17 Put paper towels in the cylinders (A) to avoid getting debris in them when scraping the old gasket material (B)



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Fig. Fig. 18 Use a gasket scraper to remove the bulk of the old head gasket from the mating surface



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Fig. Fig. 19 When installing the cylinder head bolts, always use a torque wrench



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Fig. Fig. 20 Make sure to use the proper sequence when tightening the head bolts-4-cylinder shown

  1. Drain the cooling system into a clean container; the coolant can be reused if it is still good.
  2.  
  3. Remove the air cleaner.
  4.  
  5. Remove the intake and exhaust manifolds. Removal of these parts is covered later in this section.
  6.  
  7. Remove the alternator bracket bolts.
  8.  
  9. If the car has air conditioning, remove the A/C compressor bracket bolts and position the compressor to one side. Do not disconnect any of the refrigerant lines.
  10.  
  11. Label and disconnect all the vacuum and electrical connections from the cylinder head.
  12.  
  13. Disconnect the upper radiator hose.
  14.  
  15. Label and disconnect the spark plug wires. Remove the plugs.
  16.  
  17. Remove the rocker arm cover (valve cover), rocker arms and pushrods. Their removal is covered later in this section. Keep these parts in order; they must be returned to their original locations.
  18.  
  19. Remove the cylinder head bolts and carefully lift off the cylinder head.
  20.  
  21. Thoroughly clean the cylinder block and head mating surfaces. Check the block and head for flatness before installing the head. Clean out the bolt holes in the cylinder block; any dirt in them will affect the head bolt torque measurement.
  22.  

To install:

  1. Install a new gasket over the dowel pins on the cylinder block. The gasket, block and head must be absolutely free of any grease, oil, or other foreign matter.
  2.  
  3. Carefully lower the cylinder head into place on the block.
  4.  
  5. Coat the head bolt threads with sealer and install finger-tight.
  6.  
  7. Tighten the bolts in the sequence shown, in three equal and progressive steps to the specified torque. Final torque is 90 ft. lbs. (120 Nm.).
  8.  
  9. The rest of installation is the reverse of removal. Be sure to use new gaskets on the manifolds. Lubricate all valve train parts with clean oil before assembly. See the rocker arm removal and installation procedure later in this section for rocker arm installation. It is not necessary to re-torque the cylinder head once it has been installed.
  10.  

Six Cylinder


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Fig. Fig. 21 Removal and installation of the cylinder head-6-cylinder engine shown



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Fig. Fig. 22 Cylinder head bolt tightening sequence-6-cylinder engine shown



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Fig. Fig. 23 An electric drill equipped with a wire wheel will expedite complete gasket removal



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Fig. Fig. 24 Check the cylinder head for warpage along the center using a straightedge and a feeler gauge



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Fig. Fig. 25 Be sure to check for warpage across the cylinder head at both diagonals

  1. Remove the intake manifold. This procedure is covered later in this section.
  2.  
  3. Disconnect the exhaust pipe from the exhaust manifold flange. You will need new bolts to reconnect these parts if you are working on the right cylinder head, see the exhaust manifold removal procedure later in this section.
  4.  
  5. If you are working on the left cylinder head, remove the alternator bracket and stud. Remove the heat stove pipe and the PULSAIR pipe (air supply pipe for 1981). Remove the oil dipstick tube bracket from the head.
  6.  
  7. Remove the valve covers. Loosen the rocker arms until they can be pivoted aside, and remove the pushrods. Keep the pushrods in order; they must be returned to their original positions.
  8.  
  9. Remove the cylinder head bolts. Carefully lift off the cylinder head.
  10.  
  11. Thoroughly clean the cylinder block and head mating surfaces. Check the block and head for flatness before installing the head. See the "Engine Rebuilding" section at the end of this section for details on how to do this. Clean out the bolt holes in the cylinder block. Any dirt in them will affect the head bolt torque readings.
  12.  

To install:

  1. Place a new gasket in position over the dowel pins. The words "This Side Up" should be showing. Do not use sealer on the gasket.
  2.  
  3. Carefully lower the cylinder head into position.
  4.  
  5. Coat the head bolt threads with sealer and install them finger-tight. Torque the cylinder head bolts in three progressive steps to the specified torque, using the pattern shown here. Final torque is 70 ft. lbs. (90 Nm.)
  6.  
  7. Install the pushrods into their original locations, pivot the rocker arms into place and tighten them just enough to hold the pushrods in place. Be sure the pushrods are correctly seated in the lifters.
  8.  
  9. Install the intake manifold.
  10.  
  11. Install the dipstick tube bracket, heat stove pipe, PULSAIR pipe (air supply pipe in 1981), and alternator bracket and stud to the left cylinder head.
  12.  
  13. Install the exhaust pipe to the manifold.
  14.  
  15. Adjust the valve lash to zero clearance, as described later in this sction.
  16.  

CLEANING & INSPECTION



Chip carbon away from the valve heads, combustion chambers, and ports, using a chisel made of hardwood. Remove the remaining deposits with a stiff wire brush.

Be sure that the deposits are actually removed, rather than burnished.

Have the cylinder head hot-tanked to remove grease, corrosion, and scale from the water passages. Clean the remaining cylinder head parts in an engine cleaning solvent. Do not remove the protective coating from the springs.

RESURFACING



All machine work should be performed by a competent, professional machine shop.

Place a straight-edge across the gasket surface of the cylinder head. Using feeler gauges, determine the clearance at the center of the straight-edge. If warpage exceeds .003 in. in a 6 in. span, or .006 in. over the total length, the cylinder head must be resurfaced.

If warpage exceeds the manufacturer's maximum tolerance for material removal, the cylinder head must be replaced.

When milling the cylinder heads of V-type engines, the intake manifold mounting position is altered, and must be corrected by milling the manifold flange a proportionate amount.

 
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