Why replace an injector?
An injector needs replacing if it malfunctions (permanent failure), or if its correct operation can no longer be guaranteed (intermittent failure). On 1.6 TDI engines, intermittent failures are rare (for example, when the needle “sticks”, causing over-consumption, jerking and popping), but permanent failures are common: short-circuited injector (damage to the coils controlling the injector, needle jamming in closed or open position). Damage to the injector may also be linked to malfunction of the high-pressure pump, which introduces filings into the diesel circuit, destroying the low-pressure pump (tank).
How much does it cost to replace an injector?
On average, a new diesel injector costs between €200 and €450. The 1.6 TDI Common Rail engine (EA188 generation, Siemens PCR 2.1 ECU) is no exception. Injectors for this engine (03L130277B, 03L130277S, A2C9626040080) now cost around €400, at the high end of the range. Professional replacement costs average between €150 and €250.
Can I change one or more injectors myself?
It's perfectly possible to change one or more injectors yourself. We'll explain the procedure in detail in this article. Please note, however, that replacing an injector sometimes requires special tools, which we'll also describe in detail.
What tools are needed to change an injector yourself?
Ideally, to change an injector on a 1.6 TDI 03L130277B, you'll need the following tools:
- diagnostics PC (ideally VCDS)
- small flathead screwdriver or metal pick
- long-nose pliers
- ratchet with XZN (triple square) size 8 male socket
- 17mm open-end wrench
- torque wrench (capable of precise 8Nm tightening)
- injector gaskets (4x 3 gaskets - firewall copper ring, oil and diesel return)
- new injector flange screws (2)
What precautions should be taken before dismantling?
Before dismantling the injectors, it's a good idea to blow them out with compressed air. Dust and debris often stagnate around these areas, and when the injectors are removed, they risk falling into the engine and polluting the oil, or even causing damage.
How do I disconnect an injector?
The VAG Group's electrical sockets (connectors) have a shape very similar to that of other automotive connectors, with one exception: the way they are removed.
A conventional plug has a small lever (red), connected to a retaining tab (green):
To remove this plug, you need to identify the direction of disconnection, i.e. the direction in which the connector is to be removed. Then push against the direction of removal (if the connector is to be removed by pulling to the left, first push to the right), keep pressure on the lever (red) and only then remove the connector.
This system keeps the connector in place even under strong vibrations, so it's vital to remove the connectors correctly.
We make a point of detailing this “simple” procedure, as many of the customers we receive have broken tabs or connectors, caused by previous mishandling. An unrepaired broken connector can lead to it becoming disconnected when the engine is running, creating a potentially dangerous situation for you, your passengers and other road users!
To clear the workspace, remove the 4 connectors (1 per injector), as well as the connector for the turbo wastegate actuator (sometimes a protective “pocket” surrounds this connector, located on the top of the turbo):
How do I remove the fuel lines?
Diesel inlets: These are the 4 rigid metal hoses in front of the injectors:
To remove these hoses, you'll need a 17mm open-end spanner to loosen and remove them one by one. Some nuts are difficult to access, so you'll need to remove the hoses one by one, starting with the one closest to the timing belt side. This will give you easier access to the nuts on the gearbox-side hoses.
Fuel return lines: fuel return lines are the small, flexible hoses on the side of the injectors:
To remove them, you'll need long-nosed pliers and a fine flathead screwdriver or metal pick, which will be used to pry the retaining staples holding them in place:
Caution! You need to hold the staples firmly with the pliers: these are spring steel parts, so they tend to “jump” when removed, and you can easily lose them, or even worse, drop them into the motor!
Once the clips have been removed, simply pull the return pipes slightly to get them out, then set them aside to clear the workspace.
How do I remove the injectors?
To remove the injectors, remove the retaining clamps. Each clamp (light green) holds 2 injectors in place, and is held in place by a screw (dark green):
To loosen the screw, you'll need an M8 male XZN socket. Once the screw has been removed, you need to rotate the injector body in its housing. The flange doesn't allow for much movement, but a few mm of play is easily possible. Once the 2 injectors are moving, you have two options:
- use an inertia hammer (not recommended, as it may damage the injector body)
- pull on the injector body by hand while rotating it (sometimes tedious, but much safer).
Cases of injectors blocked by scale in the cylinder head are extremely rare on 1.6 TDIs, but in the event of this happening, an inertia hammer may prove indispensable.
Precautions before reassembly?
Before reassembly, it's essential to check the injector wells: if there's any scale, clean them with a plastic brush.
Caution: do not use a wire brush, and certainly not a drill brush! The aluminum cylinder head may be marked, and the oil seal may leak, allowing oil to flow into the cylinder, or carbonize in the well, blocking the injector.
Also check that all fireproof seals (copper gaskets) have come with the injectors. If this is not the case, use a fire-gasket extractor or a long flathead screwdriver to remove the gasket.
Blow compressed air into the threads of the injector flange screws in the cylinder head, to remove any oil that has sunk to the bottom.
If possible (or necessary), brush the injector bodies with a grinding wheel, without touching the nose. You can use a pick to remove scale from around the injector nut, but don't go near the tip where the fuel vaporizes.
Caution! By brushing the tip of the injector nose, you risk damaging the spray holes, by enlarging them (even a minimal enlargement can be destructive, as the nose has 6 holes 240 micrometers in size, i.e. the size of 3 hairs put together) thus changing the injection angle and causing local overheating on the piston due to disparate injection.
Brush injector flanges if necessary to clean them.
Replace firewall gaskets (copper) and oil O-rings on injectors. Discard old flange screws, and prepare new ones (approx. 3€ incl. VAT at the dealership). Replace diesel return O-rings.
Caution! Reusing injector flange screws can lead to one of three scenarios:
- the screw will withstand another tightening (unlikely and dangerous)
- the screw will loosen because it no longer has the same clamping force, having been lengthened by it's previous angular tightening
- the screw pulls out the thread in the aluminum cylinder head
- the screw breaks in the tapped hole flush with the head
As you can see, for approx. €3, you can avoid a lot of potential problems.
Refitting the injectors
- To refit the injectors, apply a little copper grease to the injector body, between the firewall and the oil O-ring, to facilitate future disassembly.
- Insert the injectors into the flanges, then place the whole assembly in their wells, taking care not to drop the fireproof (copper) gaskets.
- Press on the injectors simultaneously to bring them down to the stop (where they belong).
- Once in place, insert the flange screw (NEW) into its slot, without applying oil or grease to the thread.
- Approach the screw by hand
- Lightly tap the injectors to ensure they are in place.
- Tighten to a precise 8 Nm, then 180° (angular tightening), i.e. half a turn
- (Repeat the procedure for the other 2 injectors if all 4 have been removed)
- Refit the diesel fuel return pipes, then use long-nose pliers to press in the retaining clips as far as they will go.
- Refit the rigid hoses one by one, tightening only on the Commonrail side
- Place handkerchiefs around the rigid hoses on the injector side
- Run the engine 1-2 times, then finally tighten the rigid hoses where the diesel has exited, and repeat the operation until all hoses have been tightened (and primed with diesel).
- Run the engine 10-15x to fill the injectors with diesel
- Refit the electrical connectors on the injectors and turbo.
- Using the VCDS (or other diagnostic tool), encode the injectors with their corresponding codes (IIC code in the picture, consisting of 6 characters):
- Run the engine again until the car starts and idles.
- Follow the injector adaptation procedure available here
- The injector change is now complete!