13 53 310 Removing and installing or replacing one fuel injector in fuel injection system (N14)
Special tools required:
- 13 0 191
- 13 0 192
- 13 0 193
- 13 0 194
- 13 0 195
- 13 0 231
- 13 0 232
Carry out installation work on fuel system only with coolant temperature below 40°C.
Fuel can emerge spontaneously at high velocity when the high-pressure line is released!
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 pipes or individual components.
- Use only fluff-free cloths.
- Seal all fuel system openings with protective caps or plugs.
Necessary preliminary tasks:
- Remove HIGH-PRESSURE RAIL
Recycling:
Fuel escapes when fuel lines are detached.
Catch and dispose of escaping fuel.
Observe country-specific waste-disposal regulations.
Removal:
Remove retainer (1) and discard.
Pull up fuel injector (2) to remove.
Procedure in event of stuck injectors:
For purposes of clarity, illustration shows and description refers to the removed engine.
Mount special tool 13 0 231 with lettering "Top" facing upwards.
Mount special tool 13 0 232.
To secure injector, turn nut (1) by hand until noticeable resistance is felt.
Turn nut on special tool 13 0 232 several turns until injector has been released from hole.
Remove special tool.
Remove injector.
The fuel injector installation procedure is described separately.
To find the correct new part, the 13-digit cylinder head number must be known.
The number can be found on the cylinder head.
Read and write down the cylinder head number.
There are two designs of the injectors and fastener.
To ensure the correct installation of the injectors/fastening components, the cylinder head number is important!
From MCGU10xxxxxxx:
Cylinder head with injector without Stop Choc.
From MCGU15xxxxxxx:
Cylinder head with injector with Stop Choc.
Injector differences:
- For injectors (1) of the first generation the connecting tube is rounded. The first part of the encapsulation is made of plastic.
Injector (1) has a compensation element without Stop Choc.
- Injector (2) of the second generation the connection tube is slightly thicker and not rounded. The first part of the encapsulation is made of metal.
Injector (2) has a decoupling element with Stop Choc.
Differences between the compensation elements and decoupling elements:
- 1) Compensation elements with retaining ring are without Stop Choc
- 2) Decoupling elements without retaining ring are with Stop Choc
Decoupling elements must be replaced after each disassembly!
Procedure for cylinder head number starting with MCGU10xxxxxxx:
Only injectors (1) of the first generation must be installed with compensation elements (2) without Stop Choc and retaining rings!
Injectors of the second generation with Stop Choc decoupling elements must not be installed!
Procedure for cylinder head number starting from MCGU15xxxxxxx:
Both injector designs may be installed into cylinder heads starting with MCGU15xxxxxxx . To do this, the injectors must be modified to Stop Choc decoupling elements (1).
Injectors (1) of the first generation may only be installed into cylinder heads starting with MCGU15xxxxxxx , if they were modified to Stop Choc decoupling elements!
Remove retaining ring (2) from injector (1) and pull off compensation element (3) without Stop Choc.
Install new Stop Choc decoupling element (2) onto injector (1) until a clicking noise is audible.
Injectors (1) of the second generation must only be installed with Stop Choc decoupling elements (2).
When reusing or replacing the injector, Stop Choc decoupling elements must be replaced.
Installation:
Installation note:
- Make sure guide pin (3) of fuel injector (2) is correctly positioned in designated hole (4) in cylinder head
- Replace seal (6) and support ring (5), making sure support ring (5) is seated correctly
- Replace retainer (1)
- Replace Teflon seal
Replacing Teflon sealing ring:
Before replacing Teflon sealing ring (1), make sure hands and work surface are clean and free of oil.
Avoid mechanical contact with injector tip (2).
Remove Teflon sealing ring (1) with special tool 13 0 191 from injector (2).
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 (2).
Slide new Teflon seal (1) onto mounting taper 13 0 195.
Use fingers and mounting taper 13 0 195 to slide Teflon seal (1) on to fuel injector (2).
- Do not use fingernails to slide on Teflon seal.
- Do not use any lubricants.
- The seal is expanded when slid on.
To bring the expanded Teflon sealing ring to its installation dimension, slide three mounting sleeves with decreasing diameters onto the injector.
Slide mounting sleeve (1) with large opening first onto injector (2).
Do not use any lubricating agents.
First slide mounting sleeve 13 0 192 (large diameter) onto injector (1).
Then slide mounting sleeve 13 0 193 (medium diameter) onto injector (1).
Finally, press injector (1) into mounting sleeve 13 0 194 (small diameter).
Assemble engine.
Check fuel system for LEAKS .
Check function of DME.