Fuel System - Repair (n52) BMW Z4 E89

00 Safety information for working on vehicles with automatic engine start-stop function (MSA)

Observe safety precautions when working on MSA vehicles

Before carrying out practical work on the engine, always ensure that the MSA functionality is deactivated so as to prevent automatic engine starting while work is being carried out in the engine compartment.

MSA function is deactivated by

1. Deactivate MSA by means of button (1) in passenger compartment
2. Open seat belt buckle and driver's door
3. Open engine bonnet/hood and ensure that engine hood/bonnet contact is not in workshop mode

1. Workshop mode
2. Basic setting (engine hood/bonnet open) B = 7 mm

To make sure that the engine hood/bonnet contact is at the basic setting, if necessary press the hood/bonnet contact up to the limit position before starting work and slowly release.

Scheme 111

When working with diagnosis tools

1. Observe instructions in diagnosis tool

Feature of this version with ambient pressure

The connection for the vacuum hose of the fuel pressure regulator is located between the throttle and the air cleaner or on the air cleaner.

Test precondition

The correct fuel pressure regulator is fitted.

1. Using the EPC, check whether the fuel pressure regulator suitable for the car is fitted

Connect test adapter.

Description of operation

The control function of the fuel pressure regulator must be guaranteed under all operating conditions. The fuel pump must always be able to generate a higher fuel pressure than the pressure regulated by the pressure regulator.

The injection rate is adjusted by means of the injection time; the injection time is controlled by the DME.

Description of operation: fuel return line

When the engine is at a standstill and the ignition key is in position 0, the fuel return line after the pressure regulator is at zero pressure.

Description of operation: pressure retaining function

The pressure regulator closes when the engine is at a standstill and the ignition key is in position 0. The fuel pressure in the delivery line is retained over an extended period. A non-return valve closes in the fuel pump. These measures help to retain the fuel pressure in the fuel system. Extended starting times are thus avoided.

Complaint: drive characteristic faults, lack of power

1. Run engine at idle speed and measure fuel pressure.

If the measured value is less than the nominal value - 0.2 bar

1. Line cross-sections in fuel feed are constricted or fuel filter is clogged
2. Fuel pump voltage supply is not O.K.: e.g. as a result of high contact resistance (corrosion) in plug connection between wiring harness and fuel pump.

If the measured value is greater than the nominal value + 0.2 bar

1. Turn off engine stop and then observe measured value.
2. If measured value drops to nominal value, then line cross-sections in fuel return are constricted or clogged.
3. Check the fuel lines for kinks.

If no kinks are visible

1. Replace return lines

If measured value remains too high, then pressure regulator is in all probability faulty.

1. Have a cleaning cloth ready and catch and dispose of escaping fuel.
2. Replace the return line but not the pressure regulator.

Complaint: starting problems

1. Run engine briefly at idle speed and switch off.
2. Note down measured value while engine is stopped.
3. Read off measured value again after approx. 20 to 30 minutes while engine is stopped.

Special tool 13 3 010 (hose clamp) is required for the following test.

If the measured value has dropped by more than 0.5 bar

1. Start engine and wait briefly for a stable pressure increase.
2. Switch off the engine and immediately pinch off the delivery line just before the pressure gauge with the special tool 13 3 010.
3. Note down measured value
4. Read off measured value again after approx. 20 to 30 minutes while engine is stopped

If the measured value has now dropped by less than 0.5 bar, the following faults can be present

1. Fault in delivery lines
2. Fault in in-tank delivery hose
3. Faulty pressure-holding non-return valve in fuel pump

Check components. Replace faulty components.

If the measured value has dropped by more than 0.5 bar again

1. Replace pressure regulator

Note. All the fuel hoses and hose clips which were detached within the framework of the checks must be replaced. Interrogate fault memory of DME control unit. Check stored fault messages. Rectify faults. Now clear the fault memory.

13 31 029 Check fuel delivery pressure (N51, N52, N52K)

Special tools required

1. 13 5 220
2. 13 5 221
3. 13 5 222
4. 11 4 310

Necessary preliminary tasks

1. Switch off ignition.
2. Remove acoustic cover.

Scheme 112

Unclip connector (1) from bracket (2). Unclip bracket (2) from fuel injection pipe.

Scheme 113

Remove dust cap (1).

Scheme 114

Procedure with the 25 bar pressure sensor

Connect the set of special tools 13 5 220 (consisting of 13 5 221 and 13 5 222) to the pressure sensor of the BMW diagnosis system.

Connect pressure sensor to the BMW diagnosis system or IMIB.

Scheme 115

Install set of special tools 13 5 220 at injection pipe and tighten knurled nut hand-tight.

Unscrew shutoff valve (1) so that valve in pressure regulator housing is closed.

Establish fuel delivery pressure.

Screw in shutoff valve (1) until a pressure reading is displayed on BMW diagnosis system or IMIB. Read off fuel delivery pressure and compare with values in BMW diagnosis system.

Scheme 116

Procedure with the 100 bar IMIB pressure sensor

For the check of fuel delivery pressure with the 100 bar IMIB pressure sensor only tool 13 5 221 is needed from the set of special tools. Unscrew special tool 13 5 222 from special tool 13 5 221.

Install special tool 13 5 221 at fuel injection pipe and tighten knurled nut hand-tight.

Unscrew shutoff valve so that valve in pressure regulator housing is closed.

Screw onto special tool 13 5 221, the special tool 11 4 310.

Screw IMIB 100 bar pressure sensor on the special tool 11 4 310.

Establish fuel delivery pressure.

Screw in shutoff valve until a pressure reading is displayed on IMIB. Read off fuel delivery pressure and compare with values in BMW diagnosis system.

Scheme 117

Note. Removal of the set of special tools 13 5 220

1. Stop engine.
2. Fully unscrew shutoff valve
3. Remove set of special tools 13 5 220 from pressure regulator housing
4. Catch and dispose of escaping fuel

Note. Read out the fault memory of the DME control unit. Check stored fault messages. Delete fault memory.

13 64 501 Removing and installing/replacing a fuel injector (N52K)

Necessary preliminary tasks

1. Remove «FUEL RAIL»(/bmw/z4/e89-2009-2013/remont/fuel-system/#fuel-system-repair-n52__13-53-240-replacing-complete-fuel) .

Recycling

Fuel escapes when fuel line is detached. Catch and dispose of escaping fuel.

Observe country-specific waste-disposal regulations.

Note. This procedure is applicable to all fuel injectors. Lever out retainers (1). Pull fuel injectors out of fuel rail.

Installation

Replace sealing rings on fuel injectors and coat with anti-friction rubber coating.

Scheme 118

Note. Check stored fault message. Now clear the fault memory. Check injection system for leaks.

13 53 240 Replacing complete fuel rail (N52K)

Necessary preliminary tasks

1. Read out fault memory of DME control unit
2. Turn off ignition
3. Remove «ACOUSTIC COVER»(/bmw/z4/e89-2009-2013/remont/oem-general-information/#maintenance-and-general-information-repair-n52__11-00-removing-and-installingreplacing-acoustic)

Recycling

Fuel escapes when fuel line is detached. Catch and dispose of escaping fuel.

Observe country-specific waste-disposal regulations.

Unclip plug connections (1) from holder (2) and disconnect.

Unclip wiring harnesses from holder (2) and connector strip.

Remove holder (2) from fuel rail.

Remove protective cap from compressed air valve.

Connect compressed air line (1) to compressed air valve.

Blow fuel back into tank with a short blast of compressed air (max. 3 bar).

Scheme 119

Unlock and detach fuel line (1).

Detach connector strip (2) in direction of arrow.

Release screws.

Tightening torque 13 53 1AZ .

Remove fuel rail (3).

Note. Modify FUEL INJECTORS only when replacing fuel rail.

Scheme 120

Close off fuel hose with special tool 13 5 281.

Scheme 121

Note. Check stored fault message. Delete fault memory.

Check injection system for leaks.

13 54 250 Removing and installing/replacing air intake hose on air filter housing (N52K)

Necessary preliminary tasks

1. Switch off ignition

Release clamps (1).

Tightening torque 13 71 3AZ .

Feed out air intake hose (2) and remove.

Scheme 122

Assemble engine.

13 54 251 Removing and installing/replacing air intake hose on throttle valve assembly (N52K)

Necessary preliminary tasks

1. Remove «AIR INTAKE HOSE»(/bmw/z4/e89-2009-2013/remont/fuel-system/#fuel-system-repair-n52__13-54-250-removing-and-installingreplacing)

Unfasten clip.

Tightening torque 13 71 13AZ .

Detach air intake hose (1) from throttle valve assembly and remove.

Scheme 123

13 54 030 Removing and installing/sealing throttle valve assembly (N52K)

Read and comply with notes on PROTECTION AGAINST ELECTROSTATIC DAMAGE (ESD protection).

Necessary preliminary tasks

1. Switch off ignition
2. Remove «INTAKE FILTER HOUSING»(/bmw/z4/e89-2009-2013/remont/fuel-system/#fuel-system-repair-n52__13-71-000-removing-and-installingreplacing)
3. Remove «AIR INTAKE HOSE»(/bmw/z4/e89-2009-2013/remont/fuel-system/#fuel-system-repair-n52__13-54-251-removing-and-installingreplacing)

Unlock plug (1) and remove.

Release screws.

Tightening torque 13 54 1AZ .

Remove throttle assembly (2).

Scheme 124

Installation

Replace sealing ring (1) of throttle assembly (2).

Scheme 125

Installation

Check stored fault messages.

Now clear the fault memory.

13 62 560 Removing and installing/replacing air-mass sensor (N52K)

Necessary preliminary tasks

1. Read out fault memory of DME control unit
2. Switch off ignition

Unlock plug (1) and remove.

Unfasten screws (2).

Tightening torque 13 62 8AZ.

Pull air-mass sensor (3) out of intake filter housing.

Scheme 126

Note. Check stored fault message. Now clear the fault memory.

13 62 010 Removing and installing/replacing differential pressure sensor (N52K)

Release screws.

Tightening torque 13 62 4AZ .

Unlock plug (1) and remove.

Pull differential pressure sensor (2) out of intake air manifold.

Scheme 127

Installation

Read out fault memory of control unit of Digital Motor Electronics (DME).

Check stored fault message.

Now clear the fault memory.

13 62 531 Replacing coolant temperature sensor (N52K)

Recycling

Catch and dispose of escaping coolant.

Observe country-specific waste-disposal regulations.

Necessary preliminary tasks

1. Read out fault memory of DME control unit
2. Switch off ignition

Coolant temperature sensor is mounted on cylinder head at front.

Unlock plug (1) and remove.

Release temperature sensor (2).

Installation

Tightening torque 13 62 5AZ .

If necessary, top up coolant.

Check COOLING SYSTEM for leaks.

Scheme 128

Note. Now clear the fault memory.

Necessary preliminary tasks

1. Remove «FUEL RAIL»(/bmw/z4/e89-2009-2013/remont/fuel-system/#fuel-system-repair-n52__13-53-240-replacing-complete-fuel) .

Recycling

Fuel escapes when fuel line is detached. Catch and dispose of escaping fuel.

Observe country-specific waste-disposal regulations.

Note. This procedure is applicable to all fuel injectors. Lever out retainers (1). Pull fuel injectors out of fuel rail.

Installation

Replace sealing rings on fuel injectors and coat with anti-friction rubber coating.

Note. Check stored fault message. Now clear the fault memory. Check injection system for leaks.

13 64 541 Replacing all fuel injectors

This work step is described in the section "Removing complete injection pipe".

13..... Removing intake port (N52K, N54, N54T)

Release screws (1). Tightening torque 13 71 4AZ . Detach intake port (2) from intake silencer housing and remove toward the top.

Scheme 129

13 71 000 Removing and installing/replacing intake filter housing (N52K)

Necessary preliminary tasks

1. Read out fault memory of DME control unit
2. Switch off ignition
3. Remove «intake duct.»(/bmw/z4/e89-2009-2013/remont/fuel-system/#fuel-system-repair-n52__13-removing-intake-port-n52k-n54)

Release screws (1).

Tightening torque 13 62 3AZ .

Release clamp (2) and detach air intake hose.

Tightening torque 13 62 5AZ .

Unlock plug (3) and remove.

Remove intake filter housing (4) towards top.

Scheme 130

Installation

Make sure intake filter housing is correctly seated on stop buffer at bottom.

Only when replacing intake filter housing, convert AIR-MASS SENSOR .

Note. Check stored fault messages. Now clear the fault memory.

13 72 001 Replacing air cleaner element (N52K)

Necessary preliminary tasks

1. Remove «intake duct»(/bmw/z4/e89-2009-2013/remont/fuel-system/#fuel-system-repair-n52__13-removing-intake-port-n52k-n54) .

Unlock retainers (1) at top and side on intake filter housing.

Scheme 131

Remove front section of intake filter housing (1) towards top.

Scheme 132

Replace air filter element (1).

Installation

Clean intake filter housing from inside.

Make sure guide (2) is correctly seated in intake filter housing.

Scheme 133

Note. Assemble engine.

13 90 500 Replacing tank vent valve (N52K)

Necessary preliminary tasks

1. Check stored fault messages
2. Switch off ignition
3. Remove «THROTTLE VALVE ASSEMBLY»(/bmw/z4/e89-2009-2013/remont/fuel-system/#fuel-system-repair-n52__13-54-030-removing-and-installingsealing)

Installation location

Tank vent valve is fitted at bottom on intake air manifold.

Unlock plug (1) and remove.

Unlock hose (2) and detach.

Unlock hose (3) on intake manifold and detach.

Detach tank vent valve (4) from bracket and remove.

Scheme 134

Note. Read out fault memory of DME control unit. Now clear the fault memory.

See also:
• ACOUSTIC COVER
• 13 53 1AZ
• PROTECTION AGAINST ELECTROSTATIC DAMAGE
• COOLING SYSTEM
• FUEL RAIL
• FUEL INJECTORS
• AIR INTAKE HOSE
• INTAKE FILTER HOUSING
• AIR INTAKE HOSE
• intake duct.
• AIR-MASS SENSOR
• THROTTLE VALVE ASSEMBLY