Series 638 – Section 6.2 Intake Manifold

Section 6.2
Intake Manifold

The intake charge air is routed to the individual cylinders by an intake manifold that is bolted to the cylinder heads. The mating surface of the intake manifold and cylinder heads are machined. The intake manifold is sealed to the cylinder heads with a gasket. If the manifold is removed, a new gasket must be installed to maintain the seal under higher boost pressure. A turbo-boost pressure sensor is mounted to the intake manifold with two bolts. See Figure "Intake Manifold and Related Parts" .‪

1.Nut‪	5.Clamp‪
2.Intake Manifold Gasket‪	6.Boost Pressure Sensor‪
3.Intake Manifold‪	7.Spring Washer‪
4.Connector Sleeve‪	8.Allen Head Screw‪

Figure 1. Intake Manifold and Related Parts

Section 6.2.1
Repair or Replacement of Intake Manifold

To determine if repair or replacement of the intake manifold is necessary perform the following procedure. See Figure "Flowchart for Repair or Replacement of Intake Manifold" .‪

Figure 2. Flowchart for Repair or Replacement of Intake Manifold

Section 6.2.2
Removal of Intake Manifold

Remove the intake manifold as follows:‪

1. Disconnect the charge-air-cooler CAC hose from the air-gas-recirculator AGR valve.
2. Remove the AGR vacuum supply hose from the AGR valve.
3. Remove the AGR bleed line from the AGR valve.
4. Remove the exhaust manifold. Refer to "7.1.2 Removal of Exhaust Manifold" .
5. Remove 12 intake manifold nuts. See Figure "Intake Manifold Parts Location" .
6. Remove the intake manifold assembly and gaskets from the cylinder heads. See Figure "Intake Manifold Parts Location" .
   

   1.Nut‪	5.Clamp‪
   2.Intake Manifold Gasket‪	6.Boost Pressure Sensor‪
   3.Intake Manifold‪	7.Spring Washer‪
   4.Connector Sleeve‪	8.Allen Head Screw‪

   Figure 3. Intake Manifold Parts Location

Section 6.2.2.1
Cleaning of Intake Manifold

Clean the intake manifold as follows:‪

1. Remove all old gasket material from the intake manifold and cylinder head(s) mating surfaces.
2. Clean the intake manifold and related parts with clean fuel oil.

   To avoid personal injury when blow drying, wear adequate eye protection (safety glasses or face plate) and do not exceed 276 kPa (40 lb/in. 2 ) air pressure.‪

3. Dry the intake manifold and related parts with compressed air.

Section 6.2.2.2
Inspection of Intake Manifold

Inspect the intake manifold as follows:‪

1. Visually check the intake manifold for cracks.
   1. If the intake manifold is cracked, replace the component. Refer to "6.2.3 Installation of Intake Manifold" .
   2. If the intake manifold is not cracked, proceed with step 2 of inspection.
2. Visually check the intake manifold surfaces for burrs or nicks.
   1. If the intake manifold is burred or nicked, repair as necessary. Refer to "6.2.3 Installation of Intake Manifold" .
   2. If the intake manifold is not burred or nicked, reuse the component. Refer to "6.2.3 Installation of Intake Manifold" .

Section 6.2.3
Installation of Intake Manifold

Install the intake manifold as follows:‪

1. Position the intake manifold with new gaskets onto the cylinder heads.
2. Install 12 intake manifold nuts and tighten. Torque nuts to 31-33 N · m (23-24 lb · ft).
3. Install the exhaust manifold. Refer to "7.1.3 Installation of Exhaust Manifold" .
4. Install the air-gas-recirculator AGR bleed line to the AGR valve.
5. Install the AGR vacuum supply hose to the AGR valve.
6. Connect the charge-air-cooler hose to the AGR valve.
7. Run engine to verify repair.