BMW Coupes and Sedans 1970-1988 Repair Guide

Intake Manifold

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REMOVAL & INSTALLATION



1600, 2000, 2002 Models
  1. Disconnect the negative battery cable.
  2.  
  3. Remove the air cleaner assembly.
  4.  
  5. Remove and tag the fuel lines, vacuum lines and electrical wiring attached to the carburetor.
  6.  
  7. Drain the cooling system.
  8.  


CAUTION
When draining coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze, and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. Disconnect the manual choke control cable. On automatic transmission equipped models, disconnect the wire connected to the choke cover.
  2.  
  3. Disconnect the accelerator linkage. On automatic transmission equipped models, disconnect the linkage at the ball socket.
  4.  
  5. Disconnect the coolant lines at the manifold.
  6.  
  7. Disconnect the dipstick support.
  8.  
  9. Remove the intake manifold by removing the retainer nuts securing the manifold in place. During removal, some of the studs may be removed with the retainer nuts. In this case replace both the stud and nut.
  10.  
  11. Remove the gasket between the manifold and cylinder head.
  12.  

To install:
  1. Position the manifold on the cylinder head studs, with a new gasket between the cylinder head and manifold. Tighten the retainer nuts to 15-17 ft. lbs. (20-24 Nm).
  2.  
  3. Connect the dipstick support and coolant lines to the manifold.
  4.  
  5. Connect the accelerator linkage, vacuum lines, electrical wiring and fuel lines removed earlier.
  6.  
  7. Connect the negative battery cable.
  8.  
  9. Fill the cooling system and bleed.
  10.  

2002Tii Models

To remove the complete manifold system, first remove the resonator pipes, then remove the intake pipe.

INDUCTION RESONATOR PIPES (SECURED WITH CLAMPS)

See Figure 1

  1. Disconnect the negative battery cable.
  2.  
  3. Remove the air filter assembly.
  4.  
  5. Remove and tag the fuel lines, starter valve cable, vacuum hoses, and all induction resonator pipes.
  6.  
  7. Disconnect the throttle return spring and remove the injection pipe from No. 1 cylinder. Remove the injector valve.
  8.  



Click image to see an enlarged view

Fig. Fig. 1: The early 2002Tii induction pipes were secured with clamps

  1. Remove the bracket bolts at the throttle housing.
  2.  
  3. Remove the vacuum hose, auxiliary air hose and injection pipe from the No. 4 cylinder.
  4.  
  5. Loosen the clamp(s) around the induction pipe(s), then remove the retaining nuts at the base.
  6.  
  7. Remove the air collector from the cylinder head.
  8.  
  9. Installation is the reverse of the removal procedure.
  10.  

INDUCTION MANIFOLDS (SECURED WITH NUTS AND WASHERS)
  1. Disconnect the negative battery cable.
  2.  
  3. Remove the air filter.
  4.  
  5. Remove the fuel line, fuel return line starter valve cable and vacuum hose from the air tube assembly.
  6.  
  7. Remove the bracket bolts on the throttle housing.
  8.  
  9. Remove the air collector support bolts at the top engine cover area.
  10.  
  11. Remove the nuts and washers from the bottom of the induction manifold.
  12.  
  13. Remove the air collector together with the induction manifolds and the throttle housing.
  14.  
  15. Installation is the reverse of the removal procedure.
  16.  

INTAKE PIPE
  1. Disconnect the negative battery cable.
  2.  
  3. After removing the air collector/induction resonator pipes as earlier in this section, remove the remaining injection pipes from the injection valves.
  4.  
  5. Disconnect the coolant hoses and electrical harness(s) at the thermostat housing and switches.
  6.  
  7. Remove the retaining nuts and washers from the cylinder head studs and remove the intake pipe.
  8.  
  9. Installation is the reverse of removal. Use new gaskets and place them on the intake opening properly so as not to interfere with the air flow.
  10.  

2500, 2800, 3000 and Bavaria Models
FRONT INTAKE MANIFOLD
  1. Drain the cooling system.
  2.  


CAUTION
When draining coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze, and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. Remove the air filter assembly.
  2.  
  3. Disconnect and tag all fuel and vacuum lines.
  4.  
  5. Disconnect the throttle linkage and connecting bars and remove the bearing block.
  6.  
  7. Disconnect the manual choke cable.
  8.  
  9. Remove the coolant hoses to the manifold or carburetor.
  10.  
  11. Remove the dipstick support.
  12.  
  13. Remove the intake manifold with the carburetor attached by unfastening the retainer nuts. Discard the manifold gasket.
  14.  
  15. Installation is the reverse of the removal procedure using new gaskets. Tighten the nuts to 15-17 ft. lbs. (20-24 Nm).
  16.  

REAR INTAKE MANIFOLD
  1. Drain the cooling system.
  2.  


CAUTION
When draining coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze, and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. Disconnect the negative battery cable.
  2.  
  3. Remove the air filter assembly.
  4.  
  5. Disconnect and tag all fuel and vacuum lines.
  6.  
  7. Disconnect the accelerator thrust bar and bearing block.
  8.  
  9. Disconnect the electrical wire from the choke cover. Remove the choke cover with the coolant lines attached.
  10.  
  11. Disconnect the heater hoses from the manifold base.
  12.  
  13. Remove the intake manifold with the carburetor attached, by unfastening the retainer nuts. Discard the manifold gasket.
  14.  
  15. Installation is the reverse of the removal procedure. Use new gaskets when installing the manifold.
  16.  

Tighten the nuts to 15-17 ft. lbs. (20-24 Nm).

3.0 CSi Models

Combine the next 2 operations to remove both the front and rear intake manifolds.

FRONT INTAKE MANIFOLD
  1. Remove the air cleaner assembly.
  2.  
  3. Drain the cooling system.
  4.  


CAUTION
When draining coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze, and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. Remove the intake air collector and the front intake pipes.
  2.  
  3. Remove the pressure regulator and support from the intake manifold.
  4.  
  5. Disconnect the coolant hoses from the thermostat housing and the wiring from the coolant switches.
  6.  
  7. Remove the flat plugs from the injection valves by carefully pulling upward.
  8.  
  9. Remove the first 3 injection valves from the manifold.
  10.  

Leave the circular pipe connected.

  1. Remove the retaining bolts from the intake manifold and remove from the cylinder head.
  2.  
  3. Installation is the reverse of removal. Install the manifold using a new gasket. Tighten the nuts to 15-17 ft. lbs. (20-24 Nm). Use new injection valve sealing rings.
  4.  

REAR INTAKE MANIFOLD
  1. Disconnect the negative battery cable.
  2.  
  3. Remove the air cleaner assembly.
  4.  
  5. Remove the intake air collector and the rear intake pipes.
  6.  
  7. Remove the pressure regulator and support from the intake manifold.
  8.  
  9. Remove the flat plugs from the injection valves by carefully pulling upwards.
  10.  
  11. Remove the 3 rear injector valves.
  12.  

Leave the circular pipe connected.

  1. Remove and tag the electrical plugs and harness from the end of the wire loom routed through the intake manifold.
  2.  
  3. Carefully pull the wire loom upward through the hole in the intake manifold.
  4.  
  5. Remove the intake manifold from the cylinder head by removing the retainer nuts. Once removed, discard the gasket.
  6.  
  7. Installation is the reverse of removal. Install the manifold using a new gasket. Tighten the nuts to 15-17 ft. lbs. (20-24 Nm). Always renew the injection valve sealing rings.
  8.  

318i and 320i Models
  1. Disconnect the negative battery cable.
  2.  
  3. Remove the air cleaner and drain the cooling system.
  4.  


CAUTION
When draining coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze, and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. Disconnect the accelerator cable, then tag and remove the vacuum hoses from the air collector.
  2.  
  3. Remove the injection line holder from the No. 4 intake tube.
  4.  
  5. Remove the No. 3 intake tube and disconnect the vacuum and coolant lines from the throttle housing.
  6.  
  7. Disconnect the hoses at the EGR valve and remove the plugs at the temperature timing switch.
  8.  
  9. Remove the cold start valve from the air collector.
  10.  
  11. Disconnect the vacuum hose and electrical harness at the timing valve.
  12.  
  13. Disconnect the remaining intake tubes at the collector. Unfasten the collector brackets at the engine and remove the collector.
  14.  
  15. Remove the air intake tubes from the manifold and remove the injector valves.
  16.  
  17. Remove the intake manifold by removing the manifold retainer nuts.
  18.  

To install:
  1. Use new gaskets and install the manifold to the engine. Tighten the nuts to 16-18 ft. lbs. (22-25 Nm).
  2.  
  3. Install the air intake tubes and the injector valves. Install the collector and bracket.
  4.  
  5. Connect the vacuum line and electrical harness(s) to the timing valve. Install the cold start valve.
  6.  
  7. Connect the line at the EGR valve and the electrical plugs at the temperature timing switch.
  8.  
  9. Connect all vacuum, cooling and fuel lines at the throttle housing. Install the accelerator cable and vacuum hoses to the air collector.
  10.  
  11. Install the air cleaner and fill the cooling system. Check all hose connections and fluid levels before operating the engine.
  12.  
  13. Connect the negative battery cable.
  14.  

All 6-Cylinder Engines
EXCEPT 524td, M5 AND M6 MODELS

Slight variations may exist among models due to model changes and updating, but the basic removal and installation remains the same.

  1. Disconnect the negative battery cable and drain the cooling system.
  2.  


CAUTION
When draining coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze, and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. Disconnect the wire harness at the airflow sensor. Remove the airflow sensor as an assembly. Disconnect the air intake hose running from the airflow sensor to the manifold.
  2.  
  3. Remove and tag the vacuum hoses and electrical plugs. Disconnect the accelerator linkage (and cruise control linkage, if so-equipped) from the throttle housing. Disconnect the throttle position sensor harness.
  4.  
  5. Disconnect the coolant hoses from the throttle housing.
  6.  
  7. Working from the rear of the manifold, disconnect the vacuum lines and the electrical harness. Tag the connectors and lines for ease of assembly.
  8.  
  9. Disconnect the fuel injector electrical plugs. Disconnect the injector harness loom from the manifold and pull out of the way.
  10.  
  11. Disconnect the fuel lines from the injector rail.
  12.  
  13. Disconnect the intake manifold support from the intake manifold at the bottom. Remove the nuts holding the intake manifold and remove the intake manifold.
  14.  

To install:
  1. Install the intake manifold with new gaskets and tighten the nuts to 16-18 ft. lbs. (22-25 Nm). Install the support and tighten to 15-17 ft. lbs. (20-24 Nm).
  2.  
  3. Install the fuel lines to the fuel rail. Install the injector harness loom and connect the fuel injector plugs.
  4.  
  5. Connect all lines and harness(s). Connect the coolant lines, the throttle position sensor and the throttle cables.
  6.  
  7. Connect the ducting from the airflow sensor to the throttle and the airflow sensor.
  8.  
  9. Fill the cooling system and connect the negative battery terminal.
  10.  

524td Models
  1. Disconnect the negative battery cable.
  2.  
  3. Loosen the clamps at either end, and remove the air hose linking the turbocharger and intake air box.
  4.  
  5. Using a crowfoot or similar type wrench, disconnect the injection lines at both the pump and injectors. Remove the lines as an assembly, and plug all openings.
  6.  
  7. Remove any remaining hoses or wires interfering with the manifold removal. Then, remove the retaining nuts and remove the manifold.
  8.  

To install:
  1. Clean all gasket surfaces, then install a new gasket, and put the manifold into position. Install the retaining nuts. Tighten the nuts to 16-18 ft. lbs. (21-23 Nm).
  2.  
  3. Reinstall the injection lines, tightening the connections to 14-18 ft. lbs. (18-23 Nm). Bleed the injection system.
  4.  
  5. Reconnect all hoses and wires that had to be disconnected. Reconnect the hose linking the turbocharger and manifold. Make sure connections are properly positioned and that the clamps are tight.
  6.  
  7. Connect the negative battery cable.
  8.  

M3 Models

A Torx® nut driver is needed to perform this operation.

  1. Disconnect the negative battery cable.
  2.  
  3. Remove the cap nuts at the outer ends of the 4 throttle necks. Then remove the mounting nuts underneath.
  4.  
  5. Make sure the engine has cooled off. Loosen the hose clamps for the air intake lines and for the fuel lines where they connect with the injection pipe. Collect fuel in a metal container.
  6.  
  7. Disconnect the throttle cable.
  8.  
  9. Pull off the intake manifold. Cut off the crankcase ventilation hose running to it from the crankcase. Then, remove the manifold and place it aside.
  10.  
  11. Pull off the throttle valve switch plug. Carefully pull the injector plate evenly off all 4 injectors.
  12.  
  13. Pull the fuel pressure regulator vacuum hose off the pressure regulator.
  14.  
  15. Remove the 2 mounting bolts for the injector pipe. Then, carefully lift off the pipe and injectors.
  16.  
  17. Unscrew the nut attaching the ball joint at the end of the throttle actuating rod to the throttle linkage. Supply a new self-locking nut.
  18.  
  19. Remove the nuts attaching the throttle necks to the cylinder head. Then, remove the 4 throttle necks as an assembly.
  20.  
  21. Separate the throttle neck assemblies by pulling them apart at the connecting pipe.
  22.  
  23. Inspect the O-rings in the connecting pipe and at the outer ends of the throttle necks. Replace as necessary.
  24.  

To install:
  1. Reverse the removal procedure to install. Use the new throttle linkage self-locking nut and the new crankcase ventilation hose.
  2.  
  3. Tighten the nuts attaching the throttle necks to the head and the intake manifold to the throttle necks to 6-8 ft. lbs. (9-11 Nm). Adjust the throttle cable.
  4.  

M5 and M6 Models

The M5 and M6 employ a manifold chamber in combination with 6 throttle necks (one for each cylinder), each of which contains its own throttle. The throttle necks are divided into 3 assemblies each containing the necks for 2 adjacent cylinders.

  1. Disconnect the negative battery terminal.
  2.  
  3. Disconnect the throttle cable. Remove the air intake hose. Remove the screws on each throttle valve assembly.
  4.  
  5. Disconnect the hose for the idle speed control, the venting hose and the oil return hose. Remove the nuts for the oil trap and pull off the air intake assembly.
  6.  
  7. Pull off the plug plate from the fuel injectors. Disconnect the fuel lines from the fuel rail. Pull of the intermediate plug for the idle speed control.
  8.  
  9. Remove the fuel rail with the fuel injectors.
  10.  
  11. Disconnect the vacuum hoses, after noting the routing pattern. Remove the 10mm nuts and the 13mm nuts. Remove the shaft connection nut. Disconnect the throttle linkage and remove the throttle bodies.
  12.  
  13. Separate the throttle bodies by detaching the connecting pipes. Check the O-rings on the pipe. Clean the throttle shafts before pulling out of the bores and do not use tools on the shaft or it may be damaged.
  14.  

To install:
  1. Install the throttle bodies together using new O-rings on the connecting pipes. Install the throttle bodies to the engine using new gaskets. Tighten the 10mm nuts to 6-8 ft. lbs. (9-11 Nm) and the 13mm nuts to 14-17 ft. lbs. (20-24 Nm).
  2.  
  3. Route and connect the vacuum hoses. Install the shaft connection nut and the throttle linkage. Install the fuel rail and the fuel connections. Connect the intermediate plug and the injector plug plate.
  4.  
  5. Check the O-rings on the air intake assembly and attach the pins at the bottom of the assembly. Install the air intake assembly.
  6.  
  7. Connect the oil return hose, the idle speed hose and the venting hose. Install the air intake duct and install the screws at each throttle. Connect the negative battery terminal.
  8.  

 
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