GM Full-Size Trucks 1988-1998 Repair Information

Valve/Cylinder Head Cover

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REMOVAL & INSTALLATION



Gasoline Engines
except 1997-98 7.4L engines

See Figures 1, 2, 3, 4 and 5

  1. Disconnect the negative battery cable. Remove the air cleaner.
  2.  
  3. Tag, disconnect and reposition as necessary any vacuum or PCV hoses that obstruct the cylinder head covers.
  4.  
  5. If necessary, remove the air cleaner box and the intake duct.
  6.  
  7. Disconnect electrical wire(s) (spark plug, etc.) from the cylinder head cover clips. You may also have to remove or move the alternator brace and PCV pipe.
  8.  
  9. Unbolt and remove the cover(s).
  10.  

Do not pry the covers off if they seem stuck. Instead, gently tap around each cover with a rubber mallet until the old gasket or sealer breaks loose.



Click image to see an enlarged view

Fig. Fig. 1: Unfasten and remove the cover bolts



Click image to see an enlarged view

Fig. Fig. 2: Remove the old gasket material

To install:
  1. Install a new gasket or apply RTV (or any equivalent) sealer to the cover prior to installation. If using sealer, follow directions on the tube.
  2.  
  3. Install the cover and mounting bolts. Tighten the bolts as follows:

    1988-95 4.3L and 4.8L engines: 90 inch lbs. (10 Nm)
     
    1996-98 4.3L engines: 106 inch lbs. (12 Nm)
     
    1988 5.0L, 5.7L engines: 65 inch lbs. (7 Nm)
     
    1989-94 5.0L, 5.7L engines: 90 inch lbs. (10 Nm)
     
    1995: 5.0L, 5.7L: 89 inch lbs. (10 Nm)
     
    1996-98: 5.0L, 5.7L: 106 inch lbs. (12 Nm)
     
    1988-91 7.4L engines: 115 inch lbs. (13 Nm)
     
    1992-96 7.4L engines: 65 inch lbs. (7 Nm)
     

  4.  
  5. Attach and reposition all vacuum and PCV hoses, and reconnect electrical and/or spark plug wires at the cover clips. Install the air cleaner.
  6.  
  7. If removed, install the air cleaner box and the intake duct.
  8.  
  9. Reconnect the battery cable.
  10.  



Click image to see an enlarged view

Fig. Fig. 3: Cylinder head cover-4.8L engines



Click image to see an enlarged view

Fig. Fig. 4: Cylinder head cover-4.3L, 5.0L and 5.7L engines



Click image to see an enlarged view

Fig. Fig. 5: Correct RTV application on the cylinder head cover

1997-98 7.4L engines
  1. Disconnect the negative battery cable.
  2.  
  3. If removing the right side cover, perform the following steps:
    1. Remove the air cleaner assembly.
    2.  
    3. Tag and disconnect the spark plug wires from the spark plugs and move the wires aside so that they will not interfere with the valve cover removal.
    4.  
    5. Remove the vent tube from the valve cover.
    6.  
    7. Remove the throttle body unit and the throttle body studs.
    8.  
    9. Unfasten the valve cover retainers and remove the cover.
    10.  
    11. Remove the old valve cover gasket, then clean any gasket residue from the gasket mating surfaces.
    12.  
    13. Inspect the valve cover and its sealing surfaces for distortion. Replace as necessary.
    14.  

  4.  
  5. If removing the left side cover, perform the following steps:
    1. Remove the PCV valve, tube and the EGR inlet tube.
    2.  
    3. Tag and disconnect the spark plug wires from the spark plugs and move the wires aside so that they will not interfere with the valve cover removal.
    4.  
    5. Unfasten the valve cover retainers and remove the cover.
    6.  
    7. Remove the old valve cover gasket, then clean any gasket residue from the gasket mating surfaces.
    8.  
    9. Inspect the valve cover and its sealing surfaces for distortion. Replace as necessary.
    10.  

  6.  

To install:
  1. If installing the right side cover, perform the following steps:
    1. Install a new valve cover gasket.
    2.  
    3. Install the valve cover and its retainers. Tighten the retainers to 72 inch lbs. (8 Nm).
    4.  
    5. Install the throttle body studs in the upper intake manifold. Tighten the studs to 108 inch lbs. (12 Nm).
    6.  
    7. Install the throttle body assembly.
    8.  
    9. Attach the vent tube to the valve cover and the spark plug wires to the spark plugs.
    10.  
    11. Install the air cleaner assembly.
    12.  

  2.  
  3. If installing the left side cover, perform the following steps:
    1. Install a new valve cover gasket.
    2.  
    3. Install the valve cover and its retainers. Tighten the retainers to 72 inch lbs. (8 Nm).
    4.  
    5. Attach the spark plug wires to the spark plugs.
    6.  
    7. Install the EGR inlet tube, the PCV valve and the PCV tube.
    8.  

  4.  
  5. Connect the negative battery cable.
  6.  

Diesel Engines

Except 1996-98 Models
  1. If removing/installing the right side cover, perform the following steps:
    1. Remove the intake manifold.
    2.  
    3. Remove the fuel injection lines for all except the No. 5 and No. 7 injectors.
    4.  
    5. Disconnect the glow plug wires.
    6.  
    7. Remove the wiring harness from the clip.
    8.  
    9. Remove the CDR valve.
    10.  
    11. Remove the cover bolts.
    12.  
    13. Remove the cover. If the cover sticks, jar it loose with a plastic or rubber mallet. NEVER pry it loose!
    14.  
    15. Installation is the reverse of removal. Clean all old RTV gasket material from the mating surfaces. Apply a 5 / 16 in. (8mm) bead of sealer to the head mating surfaces. Tighten the cover bolts to 16 ft. lbs. (22 Nm).
    16.  

  2.  
  3. If removing/installing the left side cover, perform the following steps:
    1. Remove the intake manifold.
    2.  
    3. Remove the fuel injection lines.
    4.  
    5. On trucks with air conditioning, remove the upper fan shroud.
    6.  
    7. On trucks with air conditioning, remove the compressor drive belt.
    8.  
    9. On trucks with air conditioning, remove the left exhaust manifold.
    10.  
    11. Remove the dipstick tube
    12.  
    13. On trucks with air conditioning, dismount the compressor and move it out of the way. It may be possible to avoid disconnecting the refrigerant lines. If not, Discharge the system and disconnect the lines. Cap all openings at once. See Routine Maintenance for discharging procedures.
    14.  
    15. Remove the dipstick tube front bracket from the stud.
    16.  
    17. Remove the wiring harness brackets.
    18.  
    19. Remove the rocker arm cover bolts and fuel return bracket.
    20.  
    21. Remove the cover. If the cover sticks, jar it loose with a plastic or rubber mallet. NEVER pry it loose!
    22.  
    23. Installation is the reverse of removal. Clean all old RTV gasket material from the mating surfaces. Apply a 5 / 16 in. (8 mm) bead of sealer to the head mating surfaces. Tighten the cover bolts to 16 ft. lbs. (22 Nm).
    24.  

  4.  

1996-98 Models

See Figure 6

  1. Remove the intake manifold cover.
  2.  

Do not bend the fuel lines to facilitate valve cover removal as this may damage the lines.

  1. Mark the fuel line clips an brackets to ensure proper installation.
  2.  
  3. Remove the fuel injection lines and clips.
  4.  
  5. If removing the right side cover, remove the CDR valve, CDR hose and the long pencil brace to the turbocharger.
  6.  
  7. Remove the ground strap.
  8.  
  9. If removing the right side valve cover, remove the heater hose.
  10.  
  11. If removing the left side valve cover, remove the oil level indicator tube and bracket.
  12.  
  13. Remove the fuel return line clip from the valve cover stud.
  14.  
  15. Remove the wiring harness at the rear of the valve cover from the clips and set the harness aside.
  16.  
  17. If removing the right side cover, remove the turbocharger heat shield.
  18.  
  19. Unfasten the valve cover retainers.
    1. Unfasten the valve cover retainers and remove the cover.
    2.  
    3. Remove the RTV sealer from the valve, then clean any RTV sealer residue from the valve cover mating surfaces.
    4.  
    5. Inspect the valve cover and its sealing surfaces for distortion. Replace as necessary.
    6.  

  20.  

To install:

Do not allow and RTV sealant to enter the valve cover bolt holes. This will cause a condition referred to as valve lock, and when the bolts are tightened the cylinder head casing could be damaged.

  1. Apply a 3 / 16 inch (5mm) bead of RTV sealant to the valve covers, inboard of the bolt holes. The sealer must be wet to the touch when the cover bolts are tightened.
  2.  
  3. Install the valve cover and the bolts. Tighten the bolts to 16 ft. lbs. (22 Nm).
  4.  
  5. Install the wiring harness.
  6.  
  7. If installing the right side valve cover, install the turbocharger heat shield.
  8.  
  9. Install the fuel return lines.
  10.  
  11. If installing the left side valve cover, install the oil level dipstick tube and its bracket.
  12.  
  13. If installing the right side valve cover, install the heater hose.
  14.  
  15. Install the ground strap.
  16.