Exhaust Manifolds
| ITEM | DESCRIPTION |
|---|---|
| 1 | Cylinder head |
| 2 | Connecting pipe |
| 3 | Bolt (3 of) |
| 4 | Nut (3 of) |
| 5 | Exhaust manifold |
| 6 | Turbocharger (primary turbocharger shown) |
| 7 | Manifold rear heat shield |
| 8 | Bolt |
| 9 | Bolt (2 of) |
| 10 | Manifold heat shield |
| 11 | Gasket |
The exhaust manifolds are cast from an iron alloy with a high nickel content giving excellent heat and corrosion resistance properties. They are sealed to the cylinder head by means of a steel gasket. Sacrificial plastic sleeves are used to align the manifolds. These sleeves must be changed when refitting the manifolds. Spacers on the securing bolts allow the manifolds to expand and retract with changes of temperature while maintaining the clamping loads.
The Bank 1 exhaust manifold has a connection for the High Pressure (HP) Exhaust Gas Recirculation (EGR) valve.
On single turbocharger variant vehicles the Variable Geometry Turbocharger (VGT) is attached to the left exhaust manifold and secured to three studs on a flange on the manifold with nuts. On production, no gasket is used to seal the joint surface between the VGT and the manifold. In-service vehicles will require a service gasket to be fitted if the joint surface is disturbed.
On twin turbocharger variant vehicles the secondary turbocharger is attached to the right exhaust manifold and secured to three studs on a flange on the manifold with nuts. On production, no gasket is used to seal the joint surface between the secondary turbocharger and the manifold. In-service vehicles will require a service gasket to be fitted if the joint surface is disturbed.