Intake manifold — removal and installation (BMW 7 Series E32)

Removal

Allow the engine to cool completely, then release the pressure in the fuel injection system.

Disconnect the ground cable from the battery.

Drain some coolant until the level drops below the intake manifold. If the coolant is not contaminated or discolored, it can be reused.

Loosen the clamp and disconnect the large intake duct from the throttle body. You may have to remove the entire air cleaner/intake duct assembly to create enough working space.

Disconnect the coolant hoses from the throttle body/intake manifold.

Disconnect the accelerator pedal cable and, if equipped, the cruise control cable.

Remove the pipe and the exhaust gas recirculation (EGR) valve.

Disconnect the vacuum hose from the fuel pressure regulator and disconnect the electrical connectors from the fuel injectors.
Disconnect the fuel lines from the fuel rail.

Disconnect any remaining hoses and wires attached between the intake manifold/throttle body assembly and the engine or body.

Remove the bolts and/or nuts securing the manifold to the cylinder head. Start at the ends and work toward the middle of the manifold, loosening each fastener a little at a time. Support the manifold so it doesn't fall.

Caution: The manifold can be removed without removing the throttle body, injectors, flaps, fuel pressure regulator, and carburetor. If the manifold is to be replaced, transfer all external components and lines to the new manifold before installing it on the cylinder head.

Move the manifold up and down to separate the gasket, then lift it away from the cylinder head and remove the gasket.

Installation

Remove the old gasket, then carefully clean all traces of sealant from the mating surfaces of the manifold and head. Be very careful not to scratch the soft aluminum surfaces. There are special solvents on the market that will make this task much easier. Make sure the surfaces are clean.

Check the manifold for deformation, cracks, signs of corrosion and other damage. Cracks and surface distortion are usually found near the gasket. If damage is found, have a specialist repair or replace the manifold.

Always use a new gasket when installing the manifold. If one side of the gasket is coated with graphite, it should face the cylinder head

Install the nuts and bolts and, moving from the center to the ends, gradually tighten them to the required tightening torque.

Next, install in the reverse order of removal.