GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1999 🢒 Eldorado 🢒 Engine 🢒 Engine Mechanical - 4.6L 🢒 Cylinder Head Cleaning and Inspection

Tools Required

    • J 8001 Dial Indicator Set
    • J 8358 Carbon Removal Brush
    • J 28410 Gasket Scraper (Aluminum Components)

Visual Inspection Procedure
  1. Inspect the cylinder head for the following:
    2. • Cracks, damage or pitting in the combustion chambers .
    • Scoring of the camshaft bearings and/or the journals. If the camshaft bearing journals appear to be scored or damaged, you must replace the cylinder head. DO NOT machine the camshaft bearing journals
    • Debris in the oil galleries. Continue to clean the galleries until all debris is removed.
    • Coolant leaks or damage to the deck face sealing surface. If coolant leaks are present, measure the surface warpage as described under Cylinder Head Resurfacing.
    • Damage to any gasket surfaces
    • Damage to any threaded bolt holes
    • Burnt or eroded areas in the combustion chamber
    • Cracks in the exhaust ports and combustion chambers
    • External cracks in the water chamber
    • Restrictions in the intake or exhaust passages
    • Restrictions in the cooling system passages
    • Rusted, damaged, or leaking core plugs
  2. If the cylinder head is cracked or damaged, it must be replaced. No welding or patching of the cylinder head is recommended.

Cleaning Procedure
    • Clean all cylinder head surfaces with non-corrosive solvent.
    • Blow out all the oil galleries using compressed air.
    • Remove any carbon deposits from the combustion chambers using the J 8358 .
    • Clean any debris or build-up from the lifter pockets.
    • Inspect the cylinder head again for the items noted under Visual Inspection.

Flatness Measurement Procedure

    Object Number: 55964 Size: SH
  1. Clean any remaining head gasket material from the cylinder head face using the J 28410 .
  2. Place a straight-edge diagonally across the cylinder head face surface.
  3. Measure the clearance between the straight-edge and the cylinder head using a feeler gage at four points along the straight-edge.
    4. • If warpage is less than 0.05 mm (0.002 in), the cylinder head surface does not require resurfacing.
    • If the warpage is between 0.05 mm and 0.2 mm (0.002 in and 0.008 in), you must resurface the head.

    Object Number: 70983 Size: SH
  4. If resurfacing is required, the dimension between the combustion chamber gauge pad and the deck surface (1) must be at least 10.5 mm (0.413 in).

Valve Guide Measurement Procedure

    Object Number: 156172 Size: SH
  1. Measure the valve stem(1)-to-guide(2) clearance as follows:
    2. • Excessive valve stem-to-guide clearance may cause an excessive oil consumption and may also case a valve to break. Insufficient clearance will result in noisy and sticky functioning of the valve and will disturb the engine assembly smoothness.
    • Clamp the J 8001 to the cylinder head at the camshaft cover rail.
    • Locate the dial indicator so that the movement of the valve stem from side to side (crossways to the cylinder head) will cause a direct movement of the indicator stem.
    • The dial indicator stem must contact the side of the valve stem just above the valve guide.
    • Drop the valve head about 1.6 mm (0.0064 in) off the valve seat.
    • Use light pressure when moving the valve stem from side to side in order to obtain a clearance reading.
  2. If the clearance for the intake valve is greater than 0.11 mm (0.0045 in) and a new standard diameter valve stem will not bring the clearance within specifications, the cylinder head must be replaced.
  3. If the clearance for the exhaust valve is greater than 0.12 mm (0.005 in) and a new standard diameter valve stem will not bring the clearance within specifications, the cylinder head must be replaced.
  4. Valve guide wear at the bottom 10 mm (0.39 in) of the valve guide is not significant to normal operation.