Tuesday, April 3, 2012

How to Replace Exhaust Manifold on GMC, Chevrolet and Cadillac models?

The procedure here mentioned for Exhaust manifold will cover following car models:-----
Cadillac Escalade, Chevrolet Suburban 1500 & 2500, Chevrolet Tahoe, GMC Yukon, GMC Yukon XL 1500 & 2500 (2006-2007), Yukon Denali and Yukon Denali XL (2005-2006). GMC Sierra, Chevrolet Silverado 2006-2007.

The details are mentioned for
8.1L engine and
4.8L, 5.3L, 6.0L & 6.2L Engines.

Go through complete procedure.

Exhaust Manifold

8.1L Engines
Remove or disconnect the following:

Spark plug wires
Spark plugs
Exhaust manifold heat shield bolts and shield
Exhaust manifold bolt and nuts
Exhaust manifold
Exhaust manifold gasket and discard

To install:

Clean the mating surfaces and the retainer threads.
Install or connect the following:

New exhaust manifold gasket
Exhaust manifold
Exhaust manifold bolt and nuts. Tighten the bolt to 26 ft. lbs. (35 Nm) and the nuts to 12 ft. lbs. (16 Nm).
If removed, tighten the studs to 15 ft. lbs. (20 Nm).
Heat shield. Tighten the retaining bolts and nuts to 18 ft. lbs. (25 Nm).
Spark plugs and plug wires

Exhaust Manifold
4.8L, 5.3L, 6.0L & 6.2L Engines
  1. Remove or disconnect the following: 
    Do not remove the spark plug wires from the ignition coils unless required.

    Spark plug wires from the spark plugs

    Fig. Right exhaust manifold removal-4.8L, 5.3L, 6.0L and 6.2L; left side similar

    Exhaust manifold, bolts, and gasket. Discard the gasket.
    Heat shield and bolts from the manifold, if required
To install:

Do not reuse the exhaust manifold-to-cylinder head gaskets. Upon installation of the exhaust manifold, install a NEW gasket. A improperly installed gasket or leaking exhaust system may effect On-Board Diagnostics (OBD) II system performance.

  1. Clean the exhaust manifold and heat shield in solvent. Dry the exhaust manifold with compressed air.
  2. Use a straight edge and a feeler gauge and measure the exhaust manifold cylinder head deck for warpage. An exhaust manifold deck with warpage in excess of 0.01 in. (0.25mm) within the two front or two rear runners or 0.02 in. (0.5mm) overall, may cause an exhaust leak and may effect OBD II system performance. Exhaust manifolds not within specifications must be replaced.
  3. Apply a 0.2 in. (5mm) wide band of threadlock GM P/N 12345493 or equivalent to the threads of the exhaust manifold bolts.
  4. Install the exhaust manifold gasket and exhaust manifold
  5. Install the exhaust manifold bolts and tighten, beginning with the center two bolts. Alternate from side-to-side, and work toward the outside bolts.
    1. Tighten the exhaust manifold bolts first pass to 11 ft. lbs. (15 Nm). Begin with the center 2 bolts, then alternate from side to side working outwards.
    2. Tighten the exhaust manifold bolts final pass to 18 ft. lbs. (25 Nm). Begin with the center 2 bolts, then alternate from side to side working outwards. Using a flat punch, bend over the exposed edge of the exhaust manifold gasket at the front of the right cylinder head.
  6. Install or connect the following:

    Heat shield and bolts and tighten to 80 inch lbs. (9 Nm)
    Spark plug wires
These details will help.


Car repair guide?

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