13 53 310 Removing and installing or replacing an injector (N20, N26)

Special tools required:

WARNING: Observe warning on cylinder head cover.
Disconnect NEGATIVE BATTERY TERMINAL (risk of fire due to short circuit on removal).
Electric fuel pump starts up automatically when door is opened!
Carry out installation work on fuel system only with coolant temperature below 40 °C.

WARNING: Wear full face guard and protective gloves.
Fuel can emerge spontaneously at high velocity from the fuel injectors!
To reduce the fuel pressure, place rag over fuel injector and carefully tap against the fuel injector with a spanner.
There is a risk of injury if the fuel pressure is not reduced!

IMPORTANT: Wear safety goggles.
Oil and dirt particles may get into your eyes!

Before removing the injectors, clean or vacuum off injector slots.

IMPORTANT: Injectors may be pulled out with a maximum tensile force of 2000 N and twisted only to 6 Nm (torsion movement). If these values are exceeded, the injectors must be replaced!

IMPORTANT: When assembling, it is essential to adhere to screwing sequences and tightening torques!
Failure to comply with this requirement may result in leaks!

IMPORTANT: Adhere to conditions of absolute cleanliness when working on the high-pressure fuel system.
Introduced contaminants can cause malfunctions in the system!

Do not allow any dirt particles or foreign bodies to get into the system.
Remove all traces of dirt before removing lines or separate components.
Use only fluff-free cloths.
Seal all fuel system openings with protective caps or plugs.

IMPORTANT: Carry out engine cleaning/washing only with ignition coil cover fitted.
No water may penetrate into injector slots and corrosion between injectors and cylinder head must be prevented.

NOTE:

Ignition coils must not become coated with fuel!
The resistance of the silicone material is reduced significantly by contact with fuel, which may cause the ignition coil to fail! It is therefore essential to protect the spark plug slot against ingress of fuel with a cloth!
Before installing ignition coils, clean spark plug slots with compressed air.
Make sure the spark plug slot is absolutely clean.

Necessary preliminary tasks:

Remove IGNITION COILS .
Remove and renew the PRESSURE LINE between rail and high pressure pump.

NOTE: Removal and installation of injectors are described separately from each other.
Observe screw fastening sequence without fail.

Injector removal:

Unlock connector (1) and remove.

Unscrew nuts (2).

Release screws (3) a few threads until rail (4) is loose.

Fig 1: Identifying Injector Rail, Screws And Nuts

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Turn rail (1) anticlockwise until injectors can be removed.

Fig 2: Turning Injector Rail

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NOTE: The following description applies to all injectors.

Unlock connector (1) from injectors and detach.

Slacken nut (2).

Tightening torque 12 52 2AZ .

Remove ground cable (3).

Fig 3: Identifying Ground Cable, Nut And Connector

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IMPORTANT: First, release screw (2). The, release screw (1).
Otherwise, the hold-down device may tilt.

Remove holding-down element (3).

Pull injectors upward out of cylinder head and remove.

NOTE: If several injectors are removed, ensure that each injector is reinstalled in its original location (cylinder).
Mark injectors.

Fig 4: Identifying Injector Hold-Down Device Screws

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Procedure in event of stuck injector:

Use special tool 13 0 320 to remove injectors that are stuck.

Lightly oil pull-out thread (1) and unscrew completely (see Fig 5) before using the special tool.

IMPORTANT: Pull-out thread (1) is a left-hand thread.

Fig 5: Identifying Pull-Out Thread

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Fit special tool (1) 13 0 320 on injector slot. Join screws (2) to injector slot by a few threads. Screw in pull-out thread (4) until it is possible to screw the threaded sleeves (3) onto the injectors. Screw threaded sleeves (3) onto injectors and tighten down.

Tighten down screws (2).

Tightening torque 13 53 8AZ .

Fig 6: Identifying Injector Pull-Out Thread And Screws

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IMPORTANT: Set torque wrench (1) to 5 Nm clockwise rotation. Together with special tool 13 0 320 this corresponds to a tensile force of max. 2000 N. The injector must be replaced if the torque wrench clicks when the injector is pulled out!

Fig 7: Fitting Special Tool (00 9 170) On Special Tool (13 0 320)

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Fit torque wrench (1) and special tool (2) 00 9 170 on hexagon head (3) of special tool 13 0 320 .

Turn torque wrench (1) in clockwise direction until the injector is pulled out.

After removing, fit protective caps (1 and 2) to injector tip and fuel line connection.

Installation note:

When installing a new injector:

Replace decoupling element (3).

Fig 8: Identifying Injector Tip Protective Caps
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Installation note:

When reusing fuel injector:

Replace decoupling element (1).
Replace Teflon ring (2).
A Teflon ring that has already been installed once in the cylinder head must be replaced before the injector is reinstalled.

Fig 9: Identifying Fuel Injector Decoupling Element And Teflon Ring
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Replace Teflon ring:

Before replacing the Teflon ring (1), make sure your hands and the work surface are clean and free of oil.

Avoid mechanical contact with injector tip (2).

Fig 10: Identifying Teflon Ring And Injector Tip

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Remove Teflon ring (2) from injector (1) with special tool (3) 13 0 191 from set of special tools 13 0 190 .

Use a fluff-free cloth only to remove combustion residues from cylindrical part of injector tip (do not use ultrasound or other tools/agents).

Do not clean injector tip.

Fig 11: Removing Teflon Ring From Injector With Special Tool (13 0 191)

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Slide new Teflon ring (1) onto installation cone (2) 13 0 283 from set of special tools 13 0 280 .

Fig 12: Identifying Teflon Ring And Installation Cone

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Fit Teflon ring (1) on injector tip (3) with installation cone (2) 13 0 283 from set of special tools 13 0 280 .

NOTE:

Do not use fingernails to slide Teflon ring on.
Do not use any lubricating agents.
The sealing ring is expanded when slid on.

Fig 13: Identifying Teflon Ring, Injector Tip And Installation Cone

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Using special tool (1) 13 0 281 from set of special tools 13 0 280 , push Teflon ring (2) into groove (3) on injector.

Fig 14: Pushing Teflon Ring Into Injector Groove

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To bring the widened Teflon ring to the installation dimension, special tool (1) 13 0 282 from set of special tools 13 0 280 must be slid up to limit position on injector (2).

Do not use any lubricating agents.

Fig 15: Sliding Special Tool (13 0 282) On Injector

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NOTE: Pull mounting tip (1) of special tool 13 0 282 towards rear to release installation cone (2) 13 0 281.

Fig 16: Releasing Installation Cone

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Installing injector:

Before installing injector in engines that have been run:

IMPORTANT: Injectors must not be twisted to 6 Nm!
The injector must be replaced if this value is exceeded!

Fig 17: Identifying Fuel Injector Decoupling Element And Teflon Ring

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Check injector bore for dirt.
Clean only dirty injector bores.

Important - do not damage injector!
Clean injector bore: To do so, preferably slide injector without decoupling element (1) but with new Teflon ring (2) in and out of injector bores several times.
The Teflon ring must subsequently be replaced.
Clean contact surfaces of decoupling elements (1) in cylinder head.
Replace decoupling element (1).

IMPORTANT: Injection quantity compensation!

An injector quantity compensation must be carried out if an injector is replaced or changed on the cylinder side.

Injector quantity compensation is carried out with the aid of a so-called adjustment value.

The adjustment value is printed in three digits on the injector body.

Fig 18: Identifying Injector Adjustment Value

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The adjustment value must be read off before installation!

Enter the adjustment value according to the installation location (cylinder) of the injector.

If injector quantity compensation is not carried out, the engine may run roughly or fail to start.

Description of injector quantity compensation at end of instructions.

Insert injectors in injector bores.

Tighten down screws (2).

Tightening torque 13 53 8AZ .

Fig 19: Identifying Pull-Out Thread, Threaded Sleeves And Screws On Injectors

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IMPORTANT: Set torque wrench (1) to 2 Nm counterclockwise rotation.

Fit torque wrench (1) and special tool (2) 00 9 170 on hexagon head (3) of special tool 13 0 320 .

Turn torque wrench (1) in counterclockwise direction until 2 Nm are reached.

Fig 20: Fitting Special Tool (00 9 170) On Special Tool (13 0 320) Hexagon Head

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Installation note:

Install hold-down device (1) with curvatures (black arrows) downward.

Fig 21: Installing Hold-Down Device

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Fit hold-down device (3) on injectors.

IMPORTANT: Only hand-tighten screw (1). Screw the screw (2) in by only a few threads.
Otherwise, the hold-down device may tilt.

Fig 22: Identifying Injector Hold-Down Device Screws

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Install (4) rail, manually tightening nuts (3) and bolts (2) only.

NOTE:

Rail must still be displaceable on cylinder head.
Nuts (2) must be able to be screwed on easily by hand.

Fig 23: Identifying Injector Rail, Screws And Nuts

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Firstly tighten screw (1).

Tightening torque 13 53 5AZ .

Then tighten down screw (2).

Tightening torque 13 53 5AZ .

Fig 24: Identifying Injector Hold-Down Device Screws

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First tighten screws (3).

Tightening torque 13 53 4AZ .

Then tighten nuts (2) on the injectors.

Tightening torque 13 53 6AZ .

Push on connector (1) for high pressure fuel sensor.

Fig 25: Identifying Injector Rail, Screws And Nuts

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Install pressure line (2).

Tighten nut (1) manually only.

IMPORTANT: Connect pressure line (2) without tension only.
To ensure distortion-free installation of the pressure line and to avoid damaging the thread, it must be possible for both nuts (1) to be screwed on easily by hand!

Fig 26: Identifying Pressure Line And Nut

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Follow the correct screw connection sequence.

First tighten nut on high pressure pump.
Tightening torque 13 53 7AZ .
Then tighten the nut on the rail.
Tightening torque 13 53 7AZ .

Assemble engine.

Check fuel system for tightness.

Check function of DME.

Perform an injection quantity compensation:

The adjustment value is printed in three digits on the injector body.

Fig 27: Identifying Injector Adjustment Value

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Connect BMW diagnosis system
Identify vehicle
Select "Function selection"
Select "Service functions"
Select "Engine electronics"
Select "Adjustment function"
Select "Adjust injectors"
Select "Test plan"
For each replaced injector, the adjustment value must be entered according to the installation location (cylinder).

Clean spark plug slot.

Assemble engine.

Check fuel system for tightness.

Check function of DME.