Intake Manifold: Service and Repair

Intake Manifolds, Removing And Installing (M70 Engine)



WARNING: Due to risk of personal injury be sure the engine is cold before beginning work on the cylinder head.


- Drain the coolant expansion tank and disconnect coolant hoses at tank. Remove the expansion tank from engine compartment rear bulkhead.






- Remove the cover from top of engine.


- Pry out 4 plugs from cover. Turn screws 1/4 turn to release. Lift off the cover.


- Drain the windshield washer tank. Disconnect washer fluid hose and electrical harness connector from the washer pump.






- Working at the front of engine in front of oil filler cap, pull off drip shield. Disconnect engine sensor connectors (A). remove pulse sender bracket bolts (B), lift of bracket and the d connect harness plugs from it.











NOTE: Label the harness connections before disconnecting. Disconnect the harness connectors at left and right of the EML throttle actuators. Disconnect the vacuum hose (arrows) at fuel pressure regulator. Disconnect the fuel return hose at right rear of engine. Disconnect the fuel supply hoses at the top rear of engine.


WARNING: Fuel may be expelled under pressure. Do not smoke or work near heaters or other fire hazards. keep a fire extinguisher close to you before disconnecting fuel hoses, wrap a cloth around fuel hoses to absorb any leaking fuel. Plug all open fuel lines.



NOTE: On some late production engines, a special fitting is used to retain the fuel lines to the fuel rail. Use BMW special tool no. 161050 to expand the locking clip inside the end of the fuel line fittings.


- Disconnect harness connectors at intake manifold.







- Pull off fuel injector harness connectors.


- Working at the engine compartment rear bulkhead, cut off the wire ties and remove retaining screws for wiring harness bracket. Lift off the harness and set aside.


- Disconnect air filter housing clamps and remove mass air flow sensor and intake air ducting.


- Remove the throttle housings from intake manifolds.


- Detach and remove the ignition wire loom.






- Disconnect crankcase breather hoses from cylinder head covers. Loosen intake manifold support brackets, then unbolt intake manifolds and lift off.


NOTE: Where necessary remove crankcase ventilation valve from end of manifold.


- Installation is reverse of removal. Use new gaskets and 0-rings.

- Place manifold noise insulation strip on cylinder head cover first.

- Oil dipstick guide tube is mounted with same fasteners as the ignition wire loom.

- The fuel rail is mounted with the front two fasteners of right (passenger side) manifold.



- Tighten intake manifold to cylinder head 22 Nm (17 lb)