Procedures

13 53 ... Warnings for the removal of injectors (N55)







WARNING:
Fuel, oil and dirt particles may get into your eyes.
Wear full face guard and protective gloves.
Observe warning on cylinder head cover.
Disconnect negative battery terminal (risk of fire due to short circuit on removal).
Carry out installation work on fuel system only with coolant temperature below 40 °C.
Electric fuel pump starts up automatically when door is opened.
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.
Before removing the injectors, clean or vacuum off injector slots.







IMPORTANT:
There are two different injector versions for the N55 engine.
A mixed installation of the components (hold-down device, spark plug shafts, injectors, cylinder heads, and screws) between the two hold-down device versions is not possible/permitted.

Compliance with the following notes regarding the removal of the injectors is absolutely mandatory:
- 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.
- When assembling, it is essential to adhere to screwing sequences and tightening torques.
Failure to comply with this requirement may result in leaks.
- 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 contamination before removing lines or separate components.
- Use only fluff-free cloths.
- Seal all fuel system openings with protective caps or plugs.
- High pressure lines may be re-screwed a maximum of 10 times.
- 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.
- Prior to removing injectors, remove the ignition coil of the corresponding cylinder.
- 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.
- Clean spark plug slots before installing ignition coils.
- Make sure the spark plug slot is absolutely clean.