When are fuel injectors worn out?

Hello,

I've read several times that fuel injectors eventually wear out. Could someone perhaps tell me at what mileage one should start considering a replacement, and what are the signs of a faulty injector? Nozzles are?

Best regards.
Ronny.

Hi,

Generally speaking, it's probably not possible to assign a specific mileage to this. It depends on how verschandeln the fuel was at that time.
In most cases, abrasive wear occurs on the injector nozzle, which leads to a poor spray pattern and, consequently, incomplete combustion. After replacing the nozzle, you will immediately notice a different smell coming from the exhaust. If the TDI smells like diesel fuel or an old VK diesel engine, I would replace the injectors.

I would estimate that the nozzles could last for approximately 150,000 to 200,000 kilometers.

'Can anyone possibly help me? Since I replaced my fuel injectors, I've had a very faint but audible ticking sound. It's mostly noticeable in the passenger compartment. It becomes more distinct when you slightly press the accelerator around 1800 RPM. You don't really hear it when coasting or using the engine brake, but you do hear the ticking when accelerating and at idle.'

What does it sound like when there's something wrong with the hydraulic lifters? I'm not really familiar with engine technology, and I don't know much about what components are involved in wear and tear.

Does anyone have any advice?

cry

... Your engine is now burning fuel properly again...

Unfortunately, it's typical for TDI engines that the combustion process can be somewhat harsh. PD-TDI, HDI, or CDI engines regulate this through a multi-stage injection process. A VE TDI cannot do that! Once the nozzle is open, the injection process can only be stopped, but not restarted.

Assuming everything else around your engine is fine (no stuck-open EGR valve, for example), and the injectors are not newly defective, I wouldn't worry about the noise.

Bertil wrote:

... Your engine is now burning fuel properly again... PD-TDI, HDI, or CDI engines regulate this through a multi-stage injection process. A VE TDI cannot do this! Once the nozzle is open, the injection process can only be stopped, but not restarted.

Hi,

Most VEP (Vehicle Emission Pre-conditioning) systems cannot accept a pre-injection, which is already present in the 132kW TDI engine (and likely also in the 114 and 120kW TDI engines).

The Audi A6 features a version with increased power output of 132 kW (180 PS). [...] The power and torque curves impressively demonstrate the advancements compared to the 110 kW (150 PS) V6-TDI engine. A key feature of this engine is a high-pressure radial piston pump with three pistons, the VP44-SIII from Bosch. This pump achieves pressures of up to 1850 bar at the injector. For the first time, a pre-injection system, similar to that used in common-rail systems, was implemented during cold starts and the engine warm-up phase.

Best regards,
Munch.

Mampf wrote:

...most VEP (Vehicle Emission Pre-conditioning) systems cannot perform the pre-injection that is already available in the 132kW TDI engine (and likely also in the 114 and 120kW TDI engines). The Audi A6 features a version with increased power output of 132 kW (180 PS). [...] The power and torque curves impressively demonstrate the advancements compared to the 110 kW (150 PS) V6-TDI engine. A key feature of this engine is a high-pressure radial piston pump with three pistons, the VP44-SIII from Bosch. This pump achieves pressures of up to 1850 bar at the injector. For the first time, a pre-injection system, similar to that used in common-rail systems, was implemented during cold starts and the engine warm-up phase. ...

ääähhhm sorry but every TDI has a pre-injection... it's just realized through a dual-nozzle holder with two different opening pressures (so it's purely mechanical). If that weren't the case, the TDI would sound like an old tractor (with just as harsh a combustion). For maximum noise reduction, multiple injections (sometimes two main injections) are crucial, but this is not possible with the VEP TDI system (unless someone manages to use electrically controlled injectors, as with PD or CR systems).

Hi,
I randomly came across this again. The VP44 has an electrical control system, including a solenoid valve, which allows it to achieve true pre-injection.