Chevrolet Chevette/1000 1976-1988 Repair Guide

Cylinder Head

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REMOVAL & INSTALLATION



Gasoline Engine


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Fig. Fig. 1Unfasten the retainers, then remove the timing belt cover



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Fig. Fig. 2View of the fuel pump and coil fasteners



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Fig. Fig. 3Depress the valve spring for rocker arm removal



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Fig. Fig. 4Cylinder head bolt torque sequence for gasoline engines



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Fig. Fig. 5Unfasten the retaining bolts, then ...



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Fig. Fig. 6... remove the camshaft carrier



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Fig. Fig. 7Use a suitable scraper to clean the gasket mating surfaces



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Fig. Fig. 8Remove the cylinder head from the engine block



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Fig. Fig. 9Place shop towels in the cylinders to prevent debris from entering when scraping the old gasket material



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Fig. Fig. 10Use a gasket scraper to remove the bulk of the old head gasket from the mating surface



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Fig. Fig. 11An electric drill equipped with a wire wheel will expedite complete gasket removal



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Fig. Fig. 12When installing the camshaft carrier, make sure to tighten the bolts to specifications

In order to complete the rocker arm removal a special tool (#J-25477) is necessary.

  1. Disconnect the negative battery cable.
  2.  
  3. Remove the accessory drive belts.
  4.  
  5. Remove the engine fan.
  6.  
  7. Remove the timing belt upper cover retaining screws and nuts and remove the cover.
  8.  
  9. Loosen the idler pulley and remove the timing belt from the camshaft drive sprocket.
  10.  
  11. Remove the air cleaner and silencer assembly.
  12.  
  13. Drain the cooling system. Disconnect the upper radiator hose at the thermostat and the heater hose at the intake manifold.
  14.  


CAUTION
When draining the coolant, keep in mind that cats and dogs are attracted by the ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. Remove the accelerator cable support bracket.
  2.  
  3. Remove the spark plug wires from the cam cover.
  4.  
  5. Disconnect the electrical connections at:
  6.  
    1. Idle solenoid
    2.  
    3. Choke
    4.  
    5. Temperature sending unit
    6.  
    7. Alternator
    8.  

  7. Raise the car and disconnect the exhaust pipe at the manifold.
  8.  
  9. Lower the car and remove the bolt holding the dipstick tube bracket to the exhaust manifold.
  10.  
  11. Disconnect the fuel line at the carburetor.
  12.  
  13. Remove the coil cover and disconnect the secondary voltage wire from the coil.
  14.  
  15. Remove the coil bracket fasteners and lay the coil aside.
  16.  
  17. Remove the cam cover as follows:
  18.  
    1. Remove the PCV valve.
    2.  
    3. Remove the heat stove assembly.
    4.  
    5. Remove the spark plug wiring harness from cam cover.
    6.  

  19. Remove the rocker arms by depressing the valve spring with tool #J-25477. Place the rocker arms and guides in a rack so they may be installed in the same location.
  20.  
  21. Remove the nut and gasket assemblies from the studs in the camshaft carrier. Remove the studs and cam carrier. It may be necessary to use a sharp wedge to separate the carrier from the cylinder head. Be careful not to damage the mating surfaces.
  22.  
  23. Remove the cylinder head and manifold assembly.
  24.  

To install:

  1. Install the cylinder head gasket over the dowel pins with the note "This Side Up" facing up.
  2.  
  3. Replace the cylinder head and manifold.
  4.  
  5. Replace the cam carrier. Apply a thin, continuous coat of Loctite #75 (or equivalent) to both surfaces (head and cam carrier). Wipe the excess sealer from the cylinder head. Coat the threads of the cylinder head bolts with sealing compound and install bolts finger-tight. Tighten bolts to 100 Nm (75 lb. ft.) in the proper sequence.
  6.  
  7. Install cam cover attaching studs.
  8.  
  9. Install rocker arms and apply Molycoat or equivalent.
  10.  
  11. Replace camshaft cover gasket. Clean surfaces on camshaft cover and cam carrier with degreaser. Place a 1 / 8 " bead of RTV sealer all around the cam cover sealing area. Install covers and torque retaining nut assemblies to 1.6 Nm (15 in. lbs.) while the sealer is still wet.
  12.  
  13. Install accelerator support.
  14.  
  15. Install spark plug wiring harness and heat stove assembly.
  16.  
  17. Install PCV valve.
  18.  
  19. Install coil bracket bolt. Torque to 20 Nm (15 lb. ft.).
  20.  
  21. Connect the fuel line to carburetor.
  22.  
  23. Replace dipstick tube bracket to manifold.
  24.  
  25. Raise vehicle and attach exhaust pipe to manifold.
  26.  
  27. Lower vehicle and make the electrical connections at:
  28.  
    1. Idle solenoid
    2.  
    3. Choke
    4.  
    5. Temperature sending switch
    6.  
    7. Generator
    8.  

  29. Connect spark plug wires.
  30.  
  31. Connect air cleaner and silencer assembly.
  32.  
  33. Connect upper radiator hose and heater hose at the inlet manifold.
  34.  
  35. Replace engine coolant.
  36.  
  37. Replace timing belt.
  38.  

Diesel Engine


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Fig. Fig. 13Cylinder head bolt tightening sequence for diesel engines

  1. Disconnect the negative battery cable.
  2.  
  3. Drain the cooling system.
  4.  


CAUTION
When draining the coolant, keep in mind that cats and dogs are attracted by the ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. Remove the cylinder head cover.
  2.  
  3. Disconnect the bypass hose. Remove the upper half of the front cover.
  4.  
  5. Loosen the tension pulley bolts and slide the timing belt off of the two upper gears.
  6.  
  7. Unscrew the bearing cap bolts and then remove the camshaft as detailed later in this section.
  8.  
  9. Tag and disconnect the glow plug resistor wire.
  10.  
  11. Disconnect the injector lines at the injector pump and at the injector nozzles and then remove the injector lines. Disconnect and plug the fuel leak-off hose.
  12.  
  13. Disconnect the exhaust pipe at the manifold.
  14.  
  15. Remove the oil feed pipe from the rear of the cylinder head.
  16.  
  17. Disconnect the upper radiator hose and position it out of the way.
  18.  
  19. Remove the head bolts in the sequence shown and then remove the cylinder head with the intake and exhaust manifolds installed.
  20.  

To install:

The gasket surfaces on both the head and the block must be clean of any foreign matter and free of nicks or heavy scratches. Cylinder bolt threads in the block and on the bolt must also be clean.

  1. Place a new gasket over the dowel pins with the word TOP facing up.
  2.  
  3. Apply engine oil to the threads and the seating face of the cylinder head bolts, install them and then tighten them in the proper sequence.
  4.  
  5. Install the camshaft and rocker arm assemble. Loosen the adjusting screws so that the entire rocker arm assembly is held in a free state.
  6.  
  7. Reinstall the timing belt as outlined later in this section.
  8.  
  9. Connect the upper radiator hose and the oil feed pipe.
  10.  
  11. Connect the exhaust pipe to the manifold.
  12.  
  13. Install the fuel leek-off hose. Connect the injector lines.
  14.  
  15. Connect the glow plug resistor wire.
  16.  
  17. Adjust the valve clearance as previously detailed. Install the cylinder head cover.
  18.  

CYLINDER HEAD OVERHAUL



Gasoline Engine


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Fig. Fig. 14Use a valve spring compressor tool to relieve spring tension from the valve caps



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Fig. Fig. 15Remove the spring from the valve stem in order to access the seal



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Fig. Fig. 16Invert the cylinder head and withdraw the valve from the cylinder head bore



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Fig. Fig. 17A wire wheel may be used to clean the combustion chambers of carbon deposits



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Fig. Fig. 18A dial gauge may be used to check valve stem-to-guide clearance



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Fig. Fig. 19Exploded view of the gasoline engine cylinder block and related parts (1 of 2)



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Fig. Fig. 20Valve stems may be rolled on a flat surface to check for bends



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Fig. Fig. 21The valve spring should be straight up and down when placed like this



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Fig. Fig. 22Cylinder block and related parts key list (2 of 2)



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Fig. Fig. 23Exploded view of the gasoline engine cylinder head, oil pan and related parts (1 of 2)



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Fig. Fig. 24Cylinder head, oil pan and related parts key list (2 of 2)

DISASSEMBLY

For ease in servicing cylinder head, remove generator mounting bracket, exhaust manifold and intake manifold before continuing.

  1. Using tool J-8062 or equivalent, compress valve spring and remove valve locks.
  2.  
  3. Release compressor tool and remove spring cap, spring and valve stem seal.
  4.  
  5. Remove valves from cylinder head, placing them in a rack so they may be returned to their original position.
  6.  

CLEANING AND INSPECTION
  1. Clean all carbon from combustion chambers and valve ports using tool J-8089 or equivalent.
  2.  
  3. Thoroughly clean valve guides using tool J-8101.
  4.  
  5. Clean valve stems and heads on a buffing wheel.
  6.  
  7. Clean carbon deposits from head gasket mating surface.
  8.  
  9. Inspect the cylinder head for cracks in the exhaust ports, combustion chambers, or external cracks to the water chamber.
  10.  
  11. Inspect the valves for burned heads, cracked faces or damaged stems.
  12.  


WARNING
Excessive valve stem to bore clearance will cause excessive oil consumption and may cause valve breakage. Insufficient clearance will result in noisy and sticky functioning of the valve and disturb engine smoothness.

  1. Measure valve stem clearance as follows: Clamp a dial indicator on one side of the cylinder head locating the indicator so that movement of the valve stem from side to side (crosswise to the head) will cause a direct movement of the indicator stem. The indicator stem must contact the side of the valve stem just above the valve guide. With the valve head dropped about 2.0mm off the valve seat; move the stem of the valve from side to side using light pressure to obtain a clearance reading. If clearance exceeds specifications it will be necessary to ream valve guides for oversize valves as outlined. Oversize valves are available in: 0.075mm, 0.150mm, and 0.300mm.
  2.  
  3. Check valve spring tension with tool J-8056 spring tester. Springs should be compressed to the specified height and checked against the specifications chart. Springs should be replaced if not within 10 lbs. (44N) of the specified load.
  4.  

ASSEMBLY
  1. Insert valve in proper port.
  2.  
  3. Check installed height of valve. If necessary, grind the tip of the valve to obtain a dimension of 18mm above the head. This is required to assure correct operation of the valve lash adjusters.
  4.  


WARNING
Do not grind more than 0.75mm from any valve tip, otherwise interference between the rocker arm and valve cap may occur.

  1. Install valve stem oil seal.
  2.  

Two valve stem oil seals are used. The intake is identified by the letters IN on the seal. The exhaust is identified by EX and a color coded retainer. DO NOT MIX SEALS ON INSTALLATION.

  1. Place valve spring and cap over valve stem and compress with tool J-8062.
  2.  
  3. Install valve locks and release compressor tool. Make sure that the locks seat properly in the groove on the valve stem. Grease may be used to hold the locks in place while releasing the compressor tool.
  4.  
  5. Install remaining valves in the same manner.
  6.  
  7. Check the installed height of the valve springs. Measure from the top of the spring seat, or shim, to the top of the spring. If out of specification, add shim(s) to correct.
  8.  

Diesel Engine
DISASSEMBLY AND ASSEMBLY


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Fig. Fig. 25Exploded view of the cylinder block and head for diesel engines

See Rocker Arm Removal and Installation procedure previously outlined.

 
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