Exhaust Manifolds

RH

Removal

1. Disconnect coil ignition wire from ignition coil (12029) and ignition wires from spark plugs (12405) .

2. Remove spark plugs.

3. Raise vehicle on hoist. Refer to Section 00-02.

4. Disconnect EGR valve to exhaust manifold tube (9D477) from exhaust manifold (9430) .

5. Remove transmission fluid level indicator tube (automatic transmission).

6. Remove heater inlet tube and hose.

7. Remove exhaust manifold-to-dual converter y-pipe retaining nuts.

8. Lower vehicle.

9. Remove exhaust manifold retaining bolts. Remove exhaust manifold and exhaust manifold gasket (9448) .

10. If a new RH exhaust manifold is being installed, remove heated oxygen sensor (HO2S) (9F472) .

Installation

NOTE: Lightly oil all bolt and stud threads before installation except those specifying special sealant.

1. Clean mating surfaces on exhaust manifold , cylinder head (6049) and dual converter Y pipe (5F250) .

2. Coat threads of heated oxygen sensor with high-temperature anti-seize compound. Install heated oxygen sensor into exhaust manifold . Tighten to 37-45 Nm (28-33 lb-ft)

3. Position exhaust manifold gasket and exhaust manifold on cylinder head . Start two retaining bolts.

   NOTE: A slight warpage in the exhaust manifold may cause a misalignment between the bolt holes in the cylinder head and exhaust manifold . Elongate the holes in the exhaust manifold as necessary to correct the misalignment. Do not elongate the pilot hole (lower rear bolt hole on No. 2 cylinder).

4. Install remaining exhaust manifold retaining bolts.Tighten to 30-36 Nm (22-46 lb-ft).

5. Raise vehicle.

6. Connect dual converter Y pipe to exhaust manifold. Tighten retaining nuts to 21-32 Nm (16-23 lb-ft).

7. Install transmission fluid level indicator tube (automatic transmission).

8. Lower vehicle.

9. Install heater inlet tube and hose.

10. Install spark plugs .

11. Connect ignition wires to spark plugs.

12. Connect coil ignition wire to ignition coil .

13. Connect EGR valve to exhaust manifold tube. Tighten nut to 34-47 Nm (25-35 lb-ft).

14. Start engine and check for exhaust leaks. Check transmission fluid level. Refer to Group 07.
    
    
    
    
    

    Item	Part Number	Description
    1	6049	Cylinder Head
    2A	N801648-S	Stud (4 Req'd)
    3A	N801647-S	Bolt (2 Req'd)
    4	9430	RH Exhaust Manifold
    5	9448	Exhaust Manifold Gasket
    A		Tighten to 30-36 Nm (22-46 Lb-Ft)

LH

Removal

1. Remove oil level indicator tube support bracket.

2. Disconnect heated oxygen sensor from fuel charging wiring (9D930) .

3. Disconnect ignition wires from spark plugs .

4. Raise vehicle on hoist. Refer to Section 00-02.

5. Remove exhaust manifold-to-converter and pipe retaining nuts.

6. Lower vehicle.

7. Remove exhaust manifold retaining bolts and LH exhaust manifold and exhaust manifold gasket .

8. If a new LH exhaust manifold is being installed, remove heated oxygen sensor .

Installation

NOTE: Lightly oil all bolt and stud threads before installation except those specifying special sealant.

1. Clean mating surfaces on the LH exhaust manifold, cylinder head and dual-converter and Y pipe.

    CAUTION: Do not allow anti-seize compound to enter the sensor flutes. Possible damage to heated oxygen sensor may occur.

2. Coat threads of heated oxygen sensor with high temperature anti-seize compound. Install heated oxygen sensor into exhaust manifold . Tighten to 37-45 Nm (28-33 lb-ft).

3. Position exhaust manifold and exhaust manifold gasket on the cylinder head. Install pilot bolt (lower front bolt hole on No. 5 cylinder).

   NOTE: A slight warpage in the exhaust manifold may cause a misalignment between the bolt holes in the cylinder head and the exhaust manifold . Elongate the holes in the exhaust manifold as necessary to correct the misalignment. Do not elongate the pilot hole (lower front bolt on No. 5 cylinder).

4. Install remaining exhaust manifold retaining bolts. Tighten to 30-36 Nm (22-46 lb-ft).

5. Raise vehicle.

6. Connect dual converter and pipe to exhaust manifold . Tighten retaining nuts to 21-32 Nm (16-23 lb-ft).

7. Lower vehicle.

8. Connect ignition wires to spark plugs.

9. Connect heated oxygen sensor to engine control sensor wiring (12A581) .

10. Install oil level indicator tube support bracket retaining nut. Tighten to 20-30 Nm (15-22 lb-ft).

11. Start engine and check for exhaust leaks.
    
    
    
    
    

    Item	Part Number	Description
    1	6049	Cylinder Head
    2A	N801648-S2	Stud (3 Req'd)
    3	9430	LH Exhaust Manifold
    4A	N801647-S2	Bolt (3 Req'd)
    5	9448	Exhaust Manifold Gasket
    A		Tighten to 20-33 Nm (15-22 Lb-Ft)