- Apply sealer GM P/N 12345739 or equivalent at the engine block-to-lower intake manifold mating surface. The bead should be 2.0-3.0 mm (0.08-0.12 in) wide and 3.0-5.0 mm (0.12-0.20 in) thick.
- Install the lower intake manifold.
- Apply sealer GM P/N 12345382 or equivalent to the lower intake manifold bolt threads.
- Install the lower intake manifold bolts.
- Install the heater inlet pipe.
- Install the heater inlet pipe nut.
- Install the fuel injector rail assembly.
- Install the fuel injector rail bolts.
- Install the fuel feed and return pipe retaining clip.
- Install the fuel feed and return pipe retaining clip bolt.
Notice: Failure to tighten vertical bolts before the diagonal bolts may cause an oil leak.
Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.
Tighten
Tighten the bolts in sequence to 13 N·m (115 lb in).
Tighten
Tighten the heater inlet pipe nut to 25 N·m (18 lb ft).
Important: Do not press on the fuel pressure regulator valve when installing the fuel injector rail assembly.
| 7.1. | Lubricate the fuel injector O-rings with GM P/N 1051885 or equivalent. |
| 7.2. | Install the injector nozzles into the lower intake manifold injector bores. |
| 7.3. | Press on the injector rail with the palms of both hands until the injectors are fully seated. |
Tighten
Tighten the fuel injector rail bolts to 10 N·m (89 lb in).
Tighten
Tighten the fuel feed and return pipe retaining clip bolt to 8 N·m
(71 lb in).
