LEMON Manuals: Even more car manuals for everyone
Home >> Buick >> 2015 >> Verano Premium, Automatic Trans >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 2 (Engine Mechanical - 2.4L (Lea)) >> Repair Instructions - Off Vehicle >> Cylinder Head Cleaning and Inspection (LAF, LEA, or LUK) >> Cylinder Head and Gasket Surface Cleaning and Inspection

Cylinder Head and Gasket Surface Cleaning and Inspection

WARNING: This page is about a different variant/trim than selected.
    Fig 1: Spark Plugs
    GM1825073Courtesy of GENERAL MOTORS COMPANY
  1. Remove the spark plugs.
  2. Inspect the cylinder head gasket and mating surfaces for leaks, corrosion and blow-by. If the gasket has failed, use the following faults to determine the cause:
    1. Improper installation
    2. Loose or warped cylinder head
    3. Missing, off location or not fully seated dowel pins
    4. Corrosion in the seal area around the coolant passages
    5. Chips or debris in the cylinder head bolt holes
    6. Bolt holes in the cylinder block not drilled or tapped deep enough
    3. Fig 2: Locating Combustion Chambers
    GM415011Courtesy of GENERAL MOTORS COMPANY
  3. Inspect the cylinder head gasket surface.
    • Cylinder head may be reused if corrosion is found only outside a 4 mm (0.375 in) band around each combustion chamber (1).
    • Replace the cylinder head if the area between the valve seats is cracked (2).
    • Replace the cylinder head if corrosion has been found inside a 4 mm (0.375 in) band around each combustion chamber (3).
  4. Clean the cylinder head bolts.
  5. Ensure proper use of room temperature vulcanizing (RTV) sealant. Use of Room Temperature Vulcanizing (RTV) and Anaerobic Sealant 
    6. NOTE:

    Do not use a wire brush on any gasket sealing surface.

  6. Remove the sealant from the rear cap mating surface with EN-28410  remover. Care must be used to avoid gouging or scraping the sealing surfaces.
  7. Clean the cylinder head. Remove all varnish, soot and carbon to the bare metal.
  8. Clean the valve guides.
  9. Clean the threaded holes. Use a nylon bristle brush.
  10. Clean the remains of the sealer from the plug holes.
  11. Inspect the cylinder head bolts for damaged threads or stretching and damaged heads caused by improper use of tools.
  12. Replace all suspect bolts.
  13. Inspect the cylinder head for cracks. Check between the valve seats and in the exhaust ports.
    14. NOTE:

    Do not attempt to weld the cylinder head, replace it.

  14. Inspect the cylinder head deck for corrosion, sand inclusions and blow holes.
    15. Fig 3: Checking Cylinder Head Deck Surface For Flatness
    GM2146352Courtesy of GENERAL MOTORS COMPANY
  15. Using a straight edge (1) and feeler gauge (2), inspect the cylinder head deck surface for flatness. Refer to Engine Mechanical Specifications (LAF, LEA, or LUK) . If the cylinder head is out of specification, replace the cylinder head. Do not machine the cylinder head.
  16. Inspect all the threaded holes for damage. Threads may be reconditioned with thread inserts.
  17. Inspect the sealing surfaces.
    18. Fig 4: Cylinder Head Plugs
    GM1825071Courtesy of GENERAL MOTORS COMPANY
  18. Inspect the cylinder head plugs and verify the oil orifice is clear and free of debris.
    19. Fig 5: Bearing Caps
    GM2209840Courtesy of GENERAL MOTORS COMPANY
  19. Clean the sealant from the rear cap mating surface with EN-28410  remover. Care must be used to avoid gouging or scraping the sealing surfaces.
  20. Inspect the intake camshaft bearing rear cap (1) for damage.
  21. Inspect the rear bearing mating surfaces for damage.
  22. Inspect the camshaft bearing caps (2) for damage.
  23. Inspect the camshaft front bearing caps (3) for damage.
    24. Fig 6: Spark Plugs
    GM1825073Courtesy of GENERAL MOTORS COMPANY
    CAUTION:

    Refer to Component Fastener Tightening Caution .

  24. Install the spark plugs. Tighten the plugs to 20 N.m (15 lb ft).
scientia non olet · About LEMON Manuals