2011 BMW 535i Sedan (F10) Fuel Injector Removal and Replacement (N55 Engine)
This guide details the procedure for removing and replacing a fuel injector on the N55 engine, specifically for the 2011 BMW 535i Sedan (F10). It covers necessary tools, preliminary tasks, step-by-step instructions, and critical post-installation procedures like injection quantity compensation.
General Information
Vehicle: 2011 BMW 535i Sedan (F10)
Engine: L6-3.0L Turbo (N55)
Procedure Reference: REP-REP-RAF0713N55-1353_NIEDERHALTER_OB - V.12
Engine Number Reference: 14407685 (Hold-down device concept at the top)
It is of vital importance to adhere to the warnings on removing the injectors!
Special Tools Required
- 13 0 320
- 00 9 170
- 13 0 191
- 13 0 283
- 13 0 281
- 13 0 282
Necessary Preliminary Tasks
- Disconnect the negative battery terminal (risk of fire due to short-circuiting on dismantling).
- Remove the ignition coil of the corresponding cylinder.
- Disconnect the pressure lines of the corresponding cylinder.
Injector Removal Procedure
Step 1: Disconnect Electrical Connectors
Unlock and disconnect the electrical connectors from the injectors using a small slotted screwdriver. Unlock the connector lock in the direction of the arrow. Disconnect the connector on the connector housing from the injector.
Note: The following description applies to all injectors in cylinders 1-6.
Step 2: Detach and Slacken Components
Unlock connector (1) from the injector and detach it. Slacken nut (2).
Tightening Torque for Earth Cable:
| Part Number | Type | Application | Tightening Specification | Dimension |
|---|---|---|---|---|
| 12 90 5AZ | Earth cable for ignition coils | N53 / N55 / N55 Hybrid | 5 Nm | - |
Remove the ground cable (3).
Step 3: Remove Hold-Down Device
Attention! First, release screw (2), then release screw (1). Otherwise, the hold-down device may tilt.
Remove the hold-down element (3).
Pull injectors upward out of the cylinder head and remove them.
Note: If several injectors are removed, ensure that each injector is reinstalled in its original installation location (cylinder). Mark injectors.
Step 4: Procedure for Stuck Injectors
Use special tool 13 0 320 to remove injectors that are stuck.
Lightly oil the pull-out thread (1) and unscrew it completely (refer to graphic) before using the special tool.
Attention! The pull-out thread (1) is a left-hand thread!
Step 5: Attaching Removal Tool
Fit special tool (1) 13 0 320 onto the injector slot. Join screws (2) to the injector slot by a few threads. Screw in the pull-out thread (4) until it is possible to screw the threaded sleeves (3) onto the injectors. Screw threaded sleeves (3) onto the injectors and tighten them down. Tighten down screws (2).
Tightening Torque for Threaded Sleeves:
| Part Number | Type | Application | Thread Specification | Tightening Specification | Dimension |
|---|---|---|---|---|---|
| 13 53 13AZ | Special tool 13 0 270 or 0 496 885 on injector shaft | N55 / N55 Hybrid | M6 | 8.5 Nm | - |
Step 6: Final Removal with Torque Wrench
Attention! 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 is activated when the injector is pulled out!
Fit torque wrench (1) and special tool (2) 00 9 170 onto the hexagon head (3) of special tool 13 0 320.
Turn torque wrench (1) in a clockwise direction until the injector is pulled out.
After removing, fit protective caps (1 and 2) to the injector tip and fuel line connection.
Injector Installation Procedure
Important Notes for Installation:
- When installing a new injector: Install the decoupling element (3) without fail! Failure to comply with this requirement may result in line breaks and fuel discharge!
- When reusing a running injector: Replace the decoupling element (1) without fail! Replace the Teflon ring (2) without fail! A Teflon ring that has already been installed once in the cylinder head must be replaced before the injector is reinstalled. Failure to comply with this requirement may result in line breaks and fuel discharge!
Teflon Ring Replacement:
Before replacing the Teflon ring (1), ensure your hands and the support areas are clean and free of oil. Avoid mechanical contact with the injector tip (2).
Remove the old Teflon ring (2) with special tool (3) 13 0 191 from the injector (1).
Use a fluff-free cloth only to remove combustion residues from the cylindrical part of the injector tip. Do not use ultrasound or other tools/agents. Do not clean the injector tip itself.
Mounting New Teflon Ring:
Push the new Teflon ring (1) onto the installation cone (2) 13 0 283.
Mount the Teflon ring (1) with the installation cone (2) 13 0 283 onto the injector tip (3).
Note:
- Do not use fingernails to slide the Teflon ring on.
- Do not use any lubricating agents.
- The sealing ring is expanded when slid on.
Using special tool (1) 13 0 281, push the Teflon ring into the injector groove (3).
To bring the widened Teflon ring to installation size, push special tool (1) 13 0 282 as far as it will go onto the injector (2). Do not use any lubricating agents.
Note: Pull the mounting tip (1) of special tool 13 0 282 towards the rear to release the mounting taper (2) 13 0 281.
Step 7: Installing the Injector Assembly
Insert injectors into their respective injector bores.
Fit special tool (1) 13 0 320 onto the injector slot. Join screws (2) to the injector slot by a few threads. Screw in the pull-out thread (4) until the threaded sleeves (3) can be screwed onto the injectors. Screw threaded sleeves (3) onto the injectors and tighten them down. Tighten down screws (2).
Tightening Torque for Threaded Sleeves:
| Part Number | Type | Application | Thread Specification | Tightening Specification | Dimension |
|---|---|---|---|---|---|
| 13 53 13AZ | Special tool 13 0 270 or 0 496 885 on injector shaft | N55 / N55 Hybrid | M6 | 8.5 Nm | - |
Step 8: Final Tightening of Hold-Down Device
Attention! Set torque wrench (1) to 2 Nm counter-clockwise rotation.
Fit torque wrench (1) and special tool (2) 00 9 170 onto the hexagon head (3) of special tool 13 0 320.
Turn torque wrench (1) in a counter-clockwise direction until 2 Nm is reached.
Installation note: Install the hold-down device (1) with curvatures (indicated by black arrows) downward.
Fit the hold-down device (3) onto the injectors. Tighten screws (1) and (2) only hand-tight.
Step 9: Connecting Pressure Lines
Install pressure lines onto the injectors and rail. Tighten nuts (1) and (2) manually only.
Installation note: Reinstall the line damper (3).
Firstly, tighten screw (1).
Tightening Torque for Hold-Down Device Screw (First Stage):
| Part Number | Type | Application | Thread Specification | Tightening Specification | Dimension |
|---|---|---|---|---|---|
| 13 53 6AZ. | Hold-down device to cylinder head | N55 / N55 Hybrid | M7 x 20 | 13±1 Nm | - |
Then tighten down screw (2).
Tightening Torque for Hold-Down Device Screw (Second Stage):
| Part Number | Type | Application | Thread Specification | Tightening Specification | Dimension |
|---|---|---|---|---|---|
| 13 53 6AZ. | Hold-down device to cylinder head | N55 / N55 Hybrid | M7 x 20 | 13±1 Nm | - |
Step 10: Tightening Pressure Lines
Tighten down pressure lines on injectors (1).
Tightening Torque for Injector Pressure Lines:
| Part Number | Type | Application | Thread Specification | Tightening Specification | Dimension |
|---|---|---|---|---|---|
| 13 53 9AZ | High pressure lines to rail and injection system | N55 / N55 Hybrid | M12 with transmission oil | 23±3 Nm | - |
Then tighten down pressure lines (2) on the rail.
Tightening Torque for Rail Pressure Lines:
| Part Number | Type | Application | Thread Specification | Tightening Specification | Dimension |
|---|---|---|---|---|---|
| 13 53 9AZ | High pressure lines to rail and injection system | N55 / N55 Hybrid | M12 with transmission oil | 23±3 Nm | - |
Installation note: Reinstall the line damper (3).
Step 11: Reconnecting Electrical Connectors and Ground Cable
Note: The following description applies to all injectors.
Connect connector (1) to the injectors noticeably.
Mount the ground cable (3).
Tighten nut (2).
Tightening Torque for Ground Cable Nut:
| Part Number | Type | Application | Tightening Specification | Dimension |
|---|---|---|---|---|
| 12 90 5AZ | Earth cable for ignition coils | N53 / N55 / N55 Hybrid | 5 Nm | - |
Check all connectors (1) on the injectors again for correct fit and make sure that all connectors have noticeably engaged.
Injection Quantity Compensation
Attention! Injection quantity compensation is a critical step!
An injection quantity compensation must be carried out if an injector is replaced or changed on the cylinder side.
Injection quantity compensation is performed using a so-called adjustment value, which is printed in three digits on the injector body (e.g., "7 238"). 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.
The procedure for injection quantity compensation is typically performed using a diagnostic tool and involves the following steps:
- Connect the BMW diagnosis system to the vehicle.
- Identify the vehicle.
- Navigate through the diagnostic software: Select "Function selection" > "Service functions" > "Engine electronics" > "Adjustment functions" > "Adjust injectors" > "Test plan".
- For each replaced injector, enter the adjustment value according to its specific installation location (cylinder).
Final Assembly and Checks
- Clean the spark plug slot.
- Assemble the engine components that were removed.
- Check the fuel system for leak tightness.
- Check the function of the DME (Digital Motor Electronics).
