BMW Cars 1999-06

Exhaust Manifold

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Removal & Installation



Before removing the exhaust manifold, spray the fasteners with a suitable penetrating lubricant to ease their removal, but make sure the engine is cool first! If possible apply the penetrating lubricant several times before attempting to remove any fasteners.

E30 Models
M20 Engine
  1. Disconnect the negative battery terminal.
  2.  
  3. With the exhaust system cool, disconnect the exhaust pipes from the manifolds. Remove the 3 nuts on each flange connection and lower the exhaust pipes. Support the exhaust system. Make sure the oxygen sensor wire is not being stretched.
  4.  
  5. Remove the nuts securing the manifolds to the cylinder head. Remove the manifolds.
  6.  

To install:

  1. Clean the mounting surfaces on the manifolds and the cylinder head. Check the condition of the studs and replace if necessary.
  2.  
  3. Install the new exhaust manifold heat shield gaskets and install the manifolds. Torque the nuts to 16-18 ft. lbs. (22-25 Nm). Use new copper nuts.
  4.  
  5. Connect the exhaust pipes to the manifolds using new gaskets. Connect the negative battery terminal. Start engine and check for leaks.
  6.  

M42 Engine
  1. Disconnect the negative battery terminal.
  2.  
  3. With the exhaust system cool, disconnect the exhaust pipe from the manifold. Remove the 4 nuts on the flange connection and lower the exhaust pipes. Support the exhaust system. Make sure the oxygen sensor wire is not being stretched.
  4.  
  5. Remove the nuts securing the manifold to the cylinder head. Remove the manifolds.
  6.  



Click image to see an enlarged view

Fig. Remove these bolts when removing the exhaust manifold-M42 engine



Click image to see an enlarged view

Fig. Make sure the graphite side of the exhaust manifold gasket faces the cylinder head

To install:

  1. Clean the mounting surfaces on the manifolds and the cylinder head. Check the condition of the studs and replace if necessary.
  2.  
  3. Install the new exhaust manifold gaskets with the graphite side towards the cylinder head and install the manifolds. Torque the nuts to 16-18 ft. lbs. (22-25 Nm). Use new nuts and anti-seize.
  4.  
  5. Connect the exhaust pipe to the manifolds. Connect the negative battery terminal. Start engine and check for leaks.
  6.  

S14 Engine
  1. Disconnect the negative battery cable.
  2.  
  3. With the engine cool, remove the coolant drain plug from the block.
  4.  
  5. Remove the 2 electrical connectors from the front of the coolant manifold that runs along the exhaust side of the engine.
  6.  
  7. Disconnect the radiator hose from the front of this pipe.
  8.  
  9. Then, remove all the mounting bolts for this pipe and remove it. Inspect the O-rings and replace any that are worn or damaged.
  10.  
  11. Disconnect the exhaust pipe at the manifold flange. Remove the heat shields from under the engine.
  12.  
  13. Remove the mounting nuts at the cylinder head, then remove the exhaust manifold.
  14.  
  15. Clean all gasket material from the surfaces of the manifold and head and replace the gaskets.
  16.  

To install:

  1. Position the manifold on the head, torque the manifold bolts to 7 ft. lbs. (9 Nm) and the coolant pipe mounting bolts to 5-8 ft. lbs. (7-11 Nm).
  2.  
  3. Torque the bolts at the flange attaching manifold and exhaust pipe first to 22-25 ft. lbs. (30-34 Nm) and then to 36-40 ft. lbs. (48-54 Nm).
  4.  
  5. Make sure to refill the cooling system with fresh anti-freeze/water mix and bleed the cooling system.
  6.  

E36 Models

The exhaust manifold for the 6-cylinder engines is actually two pieces and comprised of one manifold each for cylinders 1-3 and cylinders 4-6. Because the engines used in the E36 models are a slant design being tilted toward the exhaust side of the vehicle, accessing the exhaust manifold-to-cylinder head fasteners can be done from the engine compartment and from underneath the vehicle. Handy tools for this procedure include an 11mm (a 7 / 16 inch) universal (flex) socket, a long extension, a ratchet and an 11mm ( 7 / 16 inch) deep well socket. If available, due to the corrosion that tends to accumulate around exhaust fasteners, use 6 point wrenches and sockets to help prevent rounding off the fasteners.

  1. Allow the engine to cool until the coolant temperature is less than 100 °F (38°C).
  2.  
  3. Note the radio security code and disconnect the negative battery cable.
  4.  
  5. Place a protective cover over the right side fender area and using an 11mm ( 7 / 16 inch) deep well socket and ratchet, loosen all the accessible fasteners, then remove all but one of the accessible fasteners on 4-cylinder manifolds and one each for the two 6-cylinder manifolds to prevent the manifolds from falling off while working underneath the vehicle.
  6.  
  7. Raise and safely support the vehicle.
  8.  


CAUTION
Exhaust related work can generate many loose particles of debris. Wear eye protection at all times to help prevent debris from entering your eyes.

  1. Working from underneath the vehicle, use a deep well socket and ratchet or boxed end wrench to loosen the remaining manifold-to-cylinder head fasteners. If available, use a long extension and an 11mm ( 7 / 16 inch) universal socket and a ratchet to remove the loosened fasteners.
  2.  


WARNING
Use care when using an universal socket to keep the working angle as straight as possible, otherwise an excessive side load could break an exhaust stud.

  1. Spray a suitable penetrating oil onto the exhaust pipe-to-manifold mounting nuts.
  2.  
  3. Using a suitable 16mm ( 5 / 8 inch) socket, extension and ratchet, remove the exhaust pipe-to-manifold fasteners, then loosen the connection.
  4.  
  5. Safely lower the vehicle.
  6.  
  7. On 4-cylinder models, remove the fastener used to support the manifold.
  8.  
  9. On 6-cylinder models, remove the fastener used to support the cylinders 1-3 manifold
  10.  
  11. Remove the manifold by either lowering it downward or lifting it up out of the engine compartment.
  12.  
  13. On 6-cylinder models, remove the fastener used to support the cylinders 4-6 manifold and remove the manifold by either lowering it downward or lifting it up out of the engine compartment.
  14.  



Click image to see an enlarged view

Fig. Many of the exhaust manifold-to-cylinder head fasteners are easily accessed from the engine compartment-M44 engine shown



Click image to see an enlarged view

Fig. The fasteners that may be difficult to access from the engine compartment are easily accessed from beneath the vehicle



Click image to see an enlarged view

Fig. Use a deep well 6 point socket to loosen and remove the fasteners from underneath, or . . .



Click image to see an enlarged view

Fig. . . . once loosened, a swivel socket and . . .



Click image to see an enlarged view

Fig. . . . a long extension can help speed up removal time



Click image to see an enlarged view

Fig. The front pipe-to-manifold fasteners usually have a light coating of rust. Use a 6 point socket when removing them



Click image to see an enlarged view

Fig. Spray a penetrating lubricating fluid on exhaust fasteners before removal

To install:

  1. Installation is in reverse order of removal making sure to:
    1. Replace all gaskets.
    2.  
    3. Coat all exhaust manifold studs with a high temperature anti-seizing compound and tighten the manifold-to-cylinder head fasteners in a crisscross pattern working from the inside out as follows:

      M6: 88.5 inch lbs. (10 Nm)
       
      M7, EXCEPT M50/M52/M52TU/S52/S50 engines: 11 ft. lbs. (15 Nm)
       
      M7, M50/M52/M52TU/S52/S50 engines: 15 ft. lbs. (20 Nm)
       

    4.  

  2.  
  3. Upon completion check for any leakage and repair as necessary.
  4.  

M44 1.9L Engine
  1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
  2.  
  3. Remove or disconnect the following:

    Negative battery terminal
     
    Exhaust pipe from the manifold. Remove the nuts on the flange connection and lower the exhaust pipes. Support the exhaust system. Be sure the Oxygen (O 2 S) sensor wire is not being stretched.
     
    Nuts securing the manifold to the cylinder head, then remove the manifolds
     

  4.  

To install:

  1. Clean the mounting surfaces on the manifolds and the cylinder head. Check the condition of the studs and replace if necessary.
  2.  
  3. Coat the exhaust studs with an anti-locking compound.
  4.  
  5. Install or connect the following:
    NOTE
    After 1200 miles, loosen, then tighten each nut to 10 ft. lbs. (12 Nm).



    New exhaust manifold gaskets with the graphite side towards the cylinder head and install the manifolds. Nuts: 11ft. lbs. (15 Nm).
     
    Exhaust pipe to the manifolds
     
    Negative battery terminal
     

  6.  

M50/M52/S50 Engine
  1. Disconnect the negative battery terminal.
  2.  
  3. Remove the mounting nuts on each flange connection and separate the exhaust pipes from the manifold. Support the exhaust system. Make sure the oxygen sensor wire is not being stretched.
  4.  
  5. Remove the nuts securing the manifold to the cylinder head. Remove the manifolds.
  6.  

To install:

  1. Clean the mounting surfaces on the manifolds and the cylinder head. Check the condition of the studs and replace if necessary.
  2.  
  3. Install the new exhaust manifold gaskets with the graphite side towards the cylinder head and install the manifolds. Torque the nuts to 14 ft. lbs. (19 Nm). Use new nuts and anti-seize.
  4.  
  5. Install the exhaust pipe to the manifolds using new mounting nuts.
  6.  
  7. Connect the negative battery terminal.
  8.  
  9. Start engine and check for exhaust leaks.
  10.  

M52 2.5L, 2.8L, And S52 3.2L Engines
  1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
  2.  
  3. Remove or disconnect the following:

    Negative battery terminal
     
    Mounting nuts on each flange connection and separate the exhaust pipes from the manifold. Support the exhaust system. Be sure the O 2 S sensor wire is not being stretched.
     
    Nuts securing the manifold to the cylinder head
     
    Manifolds
     

  4.  

To install:

  1. Clean the mounting surfaces on the manifolds and the cylinder head. Check the condition of the studs and replace if necessary.

    New exhaust manifold gaskets with the graphite side towards the cylinder head and install the manifolds. Nuts, with exhaust studs coated with an anti-locking compound: 14 ft. lbs. (19 Nm).
     
    Exhaust pipe to the manifolds using new mounting nuts
     
    Negative battery terminal
     

  2.  

M54 & S54 Engines
  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Remove or disconnect the following:

    Negative battery terminal
     
    Mounting nuts on each flange connection and separate the exhaust pipes from the manifold. Support the exhaust system. Be sure the Oxygen (O 2 S) sensor wire is not being stretched.
     
    Nuts securing the manifold to the cylinder head
     
    Manifolds
     

  4.  

To install:

  1. Clean the mounting surfaces on the manifolds and the cylinder head. Check the condition of the studs and replace if necessary.

    New exhaust manifold gaskets with the graphite side towards the cylinder head and install the manifolds. Nuts, with exhaust studs coated with an anti-locking compound: 14 ft. lbs. (19 Nm).
     
    Exhaust pipe to the manifolds using new mounting nuts
     
    Negative battery terminal
     

  2.  

M60/M62 Engine
Left Exhaust Manifolds
  1. Disconnect negative battery cable.
  2.  
  3. Disconnect the oxygen sensor plug and remove the exhaust assembly.
  4.  
  5. Remove the alternator.
  6.  
  7. Remove the left cylinder head cover.
  8.  
  9. Remove the complete air cleaner upper section along with the mass air flow sensor.
  10.  
  11. Remove the bolts from the left and right engine mounts at the bottom.
  12.  
  13. Remove the rear engine splash guard.
  14.  
  15. Remove the bolts of the center of gravity mount to front axle carrier. Remove the left heat shields on the front axle carrier.
  16.  
  17. Lift the engine, with a suitable tool, at the front eye. Ensure clearance between the engine and the firewall.
  18.  
  19. Remove the manifold bolts and remove the manifolds downwards.
  20.  

To install:

  1. Scrape the old gasket off of the cylinder head and exhaust manifold and replace the gasket. The gasket beads face the exhaust manifolds.
  2.  
  3. Coat the upper row of the exhaust bolts with locking fluid. Position the exhaust manifold and install the bolts. Torque the mounting bolts to 16 ft. lbs. (22 Nm).
  4.  
  5. Lower the engine to its original position. Install the left heat shields and the center of gravity mount-to-front axle carrier bolts.
  6.  
  7. Install the rear engine splash guard.
  8.  
  9. Install the bolts for the left and right engine mounts at the bottom. Torque the 10mm bolts to 31 ft. lbs. (42 Nm) and the 8mm bolts to 16 ft. lbs. (22 Nm).
  10.  
  11. Install the complete air cleaner upper section along with the mass air flow sensor.
  12.  
  13. Install the left cylinder head cover and replace the gasket. Torque the mounting bolts in a criss-cross pattern to 11 ft. lbs. (15 Nm)
  14.  
  15. Install the alternator. Connect the oxygen sensor plug, and install the exhaust assembly.
  16.  
  17. Connect negative battery cable.
  18.  

Right Exhaust Manifold
  1. Disconnect negative battery cable.
  2.  
  3. Disconnect the oxygen sensor plug and remove the exhaust assembly.
  4.  
  5. Remove the right heat shields on the front axle carrier.
  6.  
  7. Remove the rear engine splash guard.
  8.  
  9. Remove the washing fluid tank.
    NOTE
    Remove the manifold for cylinders two and four first.

  10.  
  11. Remove the manifold bolts and remove the manifolds upwards.
  12.  

To install:

  1. Scrape the old gasket off of the cylinder head and exhaust manifold and replace the gasket. The gasket beads face the exhaust manifolds.
  2.  
  3. Coat the upper row of the exhaust bolts with locking fluid. Position the exhaust manifold and install the bolts. Torque the mounting bolts to 16 ft. lbs. (22 Nm).
  4.  
  5. Install the washing fluid tank.
  6.  
  7. Install the rear engine splash guard.
  8.  
  9. Install the right heat shields.
  10.  
  11. Connect the oxygen sensor plug and install the exhaust assembly.
  12.  
  13. Connect negative battery cable.
  14.  

M62 Engine
Left Side
  1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
  2.  
  3. Remove or disconnect the following:

    Negative battery cable
     
    O 2 S sensor plug and the exhaust assembly
     
    Alternator
     
    Left cylinder head trim cover
     
    Complete air cleaner upper section along with the MAF sensor
     
    Bolts from the left and right engine mounts at the bottom
     
    Rear engine splash guard
     
    Bolts of the center of gravity mount to front axle carrier
     
    Left heat shields on the front axle carrier
     

  4.  
  5. Support the engine and ensure clearance between the engine and the firewall.
  6.  
  7. Remove the manifold fasteners and remove the manifolds downwards.
  8.  

To install:

  1. Remove the old gasket off of the cylinder head and exhaust manifold and replace the gasket. The gasket beads face the exhaust manifolds.
  2.  
  3. Install or connect the following:

    Exhaust manifold, with upper row of the exhaust fasteners bolts coated with a locking agent. Mounting fasteners: 16 ft. lbs. (22 Nm).
     
    Left heat shields and the center of gravity mount-to-front axle carrier bolts
     
    Rear engine splash guard
     
    Bolts for the left and right engine mounts at the bottom. 10mm bolts: 31 ft. lbs. (42 Nm). 8mm bolts: 16 ft. lbs. (22 Nm).
     
    Complete air cleaner upper section along with the mass air flow sensor
     
    Left cylinder head cover and replace the gasket. Mounting bolts, in a crisscross pattern: 11 ft. lbs. (15 Nm)
     
    Alternator
     
    O 2 S sensor plug
     
    Exhaust assembly
     
    Negative battery cable
     

  4.  

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Remove or disconnect the following:

    Negative battery cable
     
    Oxygen O 2 S sensor plug and the exhaust assembly
     
    Alternator
     
    Left cylinder head trim cover
     
    Complete air cleaner upper section along with the MAF sensor
     
    Bolts from the left and right engine mounts at the bottom
     
    Rear engine splash guard
     
    Bolts of the center of gravity mount to front axle carrier
     
    Left heat shields on the front axle carrier
     

  4.  
  5. Support the engine and ensure clearance between the engine and the firewall.
  6.  
  7. Remove the manifold fasteners and remove the manifolds downwards.
  8.  

To install:

  1. Remove the old gasket off of the cylinder head and exhaust manifold and replace the gasket. The gasket beads face the exhaust manifolds.
  2.  
  3. Install or connect the following:

    Exhaust manifold, with upper row of the exhaust fasteners bolts coated with a locking agent. Mounting fasteners: 16 ft. lbs. (22 Nm).
     
    Left heat shields and the center of gravity mount-to-front axle carrier bolts
     
    Rear engine splash guard
     
    Bolts for the left and right engine mounts at the bottom. 10mm bolts: 31 ft. lbs. (42 Nm). 8mm bolts: 16 ft. lbs. (22 Nm).
     
    Complete air cleaner upper section along with the mass air flow sensor
     
    Left cylinder head cover and replace the gasket. Mounting bolts, in a crisscross pattern: 11 ft. lbs. (15 Nm)
     
    Alternator
     
    O 2 S sensor plug
     
    Exhaust assembly
     
    Negative battery cable
     

  4.  

Right Side
  1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
  2.  
  3. Remove or disconnect the following:
    NOTE
    Remove the manifold for cylinders number 2 and 4 first.



    Negative battery cable
     
    Oxygen (O 2 S) sensor plug and remove the exhaust assembly
     
    Right heat shields on the front axle carrier
     
    Rear engine splash guard
     
    Windshield washer fluid tank
     



    Manifold fasteners and remove the manifolds upwards
     

  4.  

To install:

  1. Remove the old gasket from the cylinder head and exhaust manifold and replace the gasket. The gasket beads face the exhaust manifolds.
  2.  
  3. Install or connect the following:

    Exhaust manifold, with upper row of the exhaust fasteners coated with a locking agent. Mounting fasteners: 16 ft. lbs. (22 Nm).
     
    Washer fluid tank
     
    Rear engine splash guard
     
    Right heat shields
     
    O 2 S sensor plug and install the exhaust assembly
     
    Negative battery cable
     

  4.  

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Remove or disconnect the following:
    NOTE
    Remove the manifold for cylinders number 2 and 4 first.



    Negative battery cable
     
    Oxygen (O 2 S) sensor plug and remove the exhaust assembly
     
    Right heat shields on the front axle carrier
     
    Rear engine splash guard
     
    Windshield washer fluid tank
     



    Manifold fasteners and remove the manifolds upwards
     

  4.  

To install:

  1. Remove the old gasket from the cylinder head and exhaust manifold and replace the gasket. The gasket beads face the exhaust manifolds.
  2.  
  3. Install or connect the following:

    Exhaust manifold, with upper row of the exhaust fasteners coated with a locking agent. Mounting fasteners: 16 ft. lbs. (22 Nm).
     
    Washer fluid tank
     
    Rear engine splash guard
     
    Right heat shields
     
    O 2 S sensor plug and install the exhaust assembly
     
    Negative battery cable
     

  4.  

M73 5.4L Engine
  1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
  2.  
  3. Remove or disconnect the following:

    Negative battery terminal
     
    Left side upper section of the air cleaner assembly along with the MAF sensor
     
    Clamp on the left and right split pipes
     
    Heat shields on the left manifold and on the steering gear
     
    Manifold and split pipe bolts on the left-hand side
     
    On the left-hand side, the front and rear manifolds along with the gaskets
     
    Nuts on the stay bolts. Remove the stay bolts in the cylinder head for the left manifold.
     
    Right side upper section of the air cleaner assembly along with the MAF sensor
     
    Windshield washer fluid tank
     
    Oil dipstick guide tube
     
    Heat shields on the right manifold
     
    On the right-hand side, the front and rear manifolds along with the gaskets
     
    Nuts on the stay bolts. Remove the stay bolts in the cylinder head for the right manifold and remove the manifold.
     

  4.  

To install:

  1. Clean the mounting surfaces on the manifolds and the cylinder head. Check the condition of the studs and replace if necessary.
  2.  
  3. Install or connect the following:

    Stay bolts in the cylinder head for the right manifold. Install the nuts onto the stay bolts.
     
    On the right-hand side, new exhaust manifold heat shield gaskets and the manifolds. Nuts: 16-18 ft. lbs. (22-25 Nm). Use new self-locking nuts.
     
    Heat shields on the right manifold
     
    Oil dipstick guide tube
     
    Windshield washer fluid tank
     
    Right side upper section of the air cleaner assembly along with the air mass sensor
     
    Stay bolts in the cylinder head for the left manifold. Install the nuts onto the stay bolts.
     
    On the left-hand side, new exhaust manifold heat shield gaskets and the manifolds. Nuts: 16-18 ft. lbs. (22-25 Nm). Use new self-locking nuts.
     
    Manifold and split pipe bolts on the left-hand side
     
    Heat shields on the left manifold and on the steering gear
     
    Clamp on the left and right split pipes
     
    Left side upper section of the air cleaner assembly along with the MAF sensor
     
    Negative battery terminal
     

  4.  

N52 Engines
  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Remove or disconnect the following:

    Negative battery cable
     
    Engine splash guard
     
    Reinforcement plate
     
    Oxygen (O 2 S) sensor plug from cylinders number 4 and 6 and remove the exhaust assembly
     
    Manifold for cylinders number 1 and 3 downwards
     
    Manifold for cylinders number 4 and 6 downwards
     

  4.  

To install:

  1. Remove the old gasket from the cylinder head and exhaust manifold and replace the gasket. The gasket beads face the exhaust manifolds.
  2.  
  3. Installation is reverse of removal.
  4.  

 
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