Envoy 2WD V8-5.3L (2007)
Important: Do not apply sealant to the first 3 threads of the bolt.
1. Apply a 5 mm (0.2 in) wide band of threadlock GM P/N 12345493 (Canadian P/N 10953488), or equivalent to the threads of the exhaust manifold
bolts.
Notice: Refer to Fastener Notice.
2. Install the exhaust manifold NEW gasket and bolts.
1. Tighten the bolts a first pass to 15 N.m (11 lb ft). Tighten the bolts beginning with the center 2 bolts. Alternate from side-to-side, and work
toward the outside bolts.
2. Tighten the bolts a final pass to 25 N.m (18 lb ft). Tighten the bolts beginning with the center 2 bolts. Alternate from side-to-side, and
work toward the outside bolts.
3. Install the heat shield, and bolts to the exhaust manifold.
Tighten the bolts to 9 N.m (80 lb in).
4. Using a flat punch, bend over the exposed edge of the exhaust manifold gasket at the front of the right cylinder head.
5. Install the spark plugs. Refer to Spark Plug Replacement for the 5.3L engine or Spark Plug Replacement for the 6.0L engine.
6. Raise the vehicle.
7. Install the nuts that secure the catalytic converter to the left exhaust manifold.
Tighten the nuts to 50 N.m (37 lb ft).
8. Lower the vehicle.
