Hummer H2. Manual — part 1895

Fig. 4: View Of Heat Shield & Bolts (Left)
Courtesy of GENERAL MOTORS CORP.

1. Install the heat shield (2), and bolts (3) to the exhaust manifold (1), if necessary.

Tighten: Tighten the bolts to 9 N.m (80 lb in).

NOTE:

Refer to Fastener Notice in Cautions and Notices.

2004 Hummer H2

2004 ENGINE Engine Exhaust - Hummer H2

Fig. 5: Exhaust Manifold Bolts, Manifold & Gasket (Left)
Courtesy of GENERAL MOTORS CORP.

2. Apply a 5 mm (0.2 in) wide band of threadlock GM P/N 12345493 (Canadian P/N 101953488) or

equivalent to the threads of the exhaust manifold bolts.

3. Install the exhaust manifold, NEW gasket and bolts.

IMPORTANT:

z

Tighten the exhaust manifold bolts as specified in the service
procedure. Improperly installed and/or leaking exhaust manifold
gaskets may affect vehicle emissions and/or On-Board Diagnostics
(OBD) II system performance.

z

The cylinder head exhaust manifold bolt hole threads must be clean
and free of debris or threadlocking material.

z

Do not apply sealant to the first three threads of the bolt.

2004 Hummer H2

2004 ENGINE Engine Exhaust - Hummer H2

Tighten:

1. Tighten the exhaust manifold bolts a first pass to 15 N.m (11 lb ft). Tighten the exhaust manifold

bolts beginning with the center two bolts. Alternate from side-to-side, and work toward the outside
bolts.

2. Tighten the exhaust manifold bolts a final pass to 25 N.m (18 lb ft). Tighten the exhaust manifold

bolts beginning with the center two bolts. Alternate from side-to-side, and work toward the outside
bolts.

4. Install the spark plug wires. Refer to Spark Plug Wire Replacement in Engine Controls - 4.8L, 5.3L and

6.0L.

5. Using a flat punch, bend over the exposed edge of the exhaust manifold gasket at the rear of the left

cylinder head.

6. Raise the vehicle.

2004 Hummer H2

2004 ENGINE Engine Exhaust - Hummer H2

Fig. 6: Exhaust Manifold Pipe Nuts (Left)
Courtesy of GENERAL MOTORS CORP.

7. Install the exhaust manifold pipe nuts.

Tighten: Tighten the nuts to 50 N.m (37 lb ft).

2004 Hummer H2

2004 ENGINE Engine Exhaust - Hummer H2