2.0 TDI Injector Wear: Early Symptoms & Causes

Hello everyone.
(Hello everyone (for those who aren't from Bavaria))

"I have a sneaking suspicion that the injectors in my Octavia 3, 4x4, manufactured in 2013 and with 190,000 km on the odometer, are wearing out, but I'd be happy to be proven wrong."

The vehicle was tuned at approximately 110,000 km. The original power output was 150 hp / 320 Nm of torque, which was increased to 180 hp / 398 Nm.
Usage profile in recent years has mainly been for short distances, approximately 15 km.
I couldn't find the MKB CKFC anywhere, but it has the same engine specifications as the CRBC or CRLB.
I heard that while the engine is supposedly a Euro 6 engine (without AdBlue), the vehicle is classified as Euro 5 due to its all-wheel drive system.

Symptoms:
My friend noticed a long time ago, even before 50,000 km, that my car runs rougher than the similarly powerful Octavias he's driven professionally as rental cars.

"Recently, I've mainly experienced reduced power at low engine speeds (below 1800 RPM), increased fuel consumption, and increasingly frequent (but not always) starting problems when the engine is cold. I've also noticed a brief, approximately 3-second hesitation more and more often under partial load, when accelerating around 2200 RPM."

The error message indicating that the EGR system has a low return rate has not appeared for a very long time.
Diagnostic system for carport available.

Would it be worthwhile to replace the injectors, considering that I plan to use the car for at least another 100,000 kilometers?
What about the possibility of using injectors that are standard in my engine's performance range (MKB CUPA or CUNA) if needed? This wouldn't be to increase power further, but rather to protect the existing injectors. Or would the tuning need to be adjusted for that?

Thank you in advance for your feedback.

Stefan.

Check TDI injectors with VCDS (Common Rail)

For anything that is not original, the tuning needs to be adjusted accordingly.
The number of people who can make a meaningful difference here is very small.

Thank you for the quick response.

If I decide to replace the injectors, I will use the original sizes again.

I still need to figure out whether I will exchange it or not.

So far, I've already extracted some data from the control unit.


Rail pressure calibration points 1/2/3 [µs] for each cylinder:

Cylinder 1: -23.6 / -28.4 / -24.0
Cylinder 2: -0.8 / -22.0 / -21.6
Cylinder 3: -23.2 / -26.8 / -20.8
Cylinder 4: 20.0 / -22.4 / -20.4


Injector correction amount at partial load (acceleration from idle) [mg].
Cylinder 1: -0.35 to -0.12.
Cylinder 2: -0.22 to -0.05.
Cylinder 3: -0.38 to -0.20.
Cylinder 4: 0.55 to 0.73.
Medium injection quantity: 3.68 to 9.66.

I have (tried) to attach a file containing the injector correction values for full load. Hopefully, it worked.

The car is still running wonderfully, but today I consciously noticed that when driving within the RPM range of 1050 to 1400 RPM, using only about one-third of the accelerator pedal, the engine clearly exhibits some hesitation or jerking.

Greetings and have a nice weekend everyone!

Stefan.

Jerking can also have other causes. For example, a malfunctioning EGR valve, problems with the mass airflow sensor, etc.

All possible sensor values that influence the injection amount should also be considered, and in cases where sensor defects or cable/connector problems cause the values to fluctuate.

A rail pressure sensor is one example; it provides setpoint and actual values in the measurement data of the engine control unit.

Best regards, Rainer.

Hello Rainer (and other interested readers),

This weekend, I have a bit of "work" ahead of me: I need to find and record the corresponding values in the control unit.

While I'm driving the bus on my routes, I often have these "great" ideas, but by the time I get to my break and can write them down, they're all gone.

I'm going to look into all the relevant pressure values and significant parameter settings, as far as available, and then continue to think about it.

Greetings.

Stefan.

Hello Stefan,

How did it turn out?

@all
I have a 2013 Golf 7 TDI 2.0 CRBC (EU5) with 180,000 km and it's making a loud knocking noise between 1200-1800 RPM.

At P at 1700 RPM, there is a noticeable shaking. Currently, I suspect it's due to the fuel injectors... but the more you read (the crazier it gets).

According to ODIS, the following calibration points have been adjusted:

01/Injector 1, Rail pressure calibration point 1/--- -18
01/Injector 1, Rail pressure calibration point 2/--- -17.6
01/Injector 1, Rail pressure calibration point 3/--- -22
01/Injector 2, Rail pressure calibration point 1/--- -8.8
01/Injector 2, Rail pressure calibration point 2/--- -9.6
01/Injector 2, Rail pressure calibration point 3/--- -9.2
01/Injector 3, Rail pressure calibration point 1/--- -24.8
01/Injector 3, Rail pressure calibration point 2/--- -21.6
01/Injector 3, Rail pressure calibration point 3/--- -17.6
01/Injector 4, Rail pressure calibration point 1/--- -56.4
01/Injector 4, Rail pressure calibration point 2/--- -26.8
01/Injector 4, Rail pressure calibration point 3/--- -18


Are injectors number 3 and number 4 faulty? Should we replace them all at once, or should we replace them individually based on their individual testing results?

Sure, here's the translation:

"Thank you in advance."

Regards,
Stirlitz.

Take a look at this for comparison:
Actuation duration + Calibration pressures for TDI injectors

What values does the LLR regulation provide?

hg
Herbert.

Hello Herbert,

I saw the linked post... and in my opinion, my values are different.

I've attached the injection deviations as an Excel file... once "cold" and once "warm," both recorded while driving on the highway. I hope you can make sense of it.

The sums of the values from the four cylinders always result in +0 or -0.


Best regards,

Hi,
The measurement is not very helpful. To measure the idle speed (LLR), it's best to start by simply measuring it in idle, once when the engine is cold and once when it's warm. A set of values including engine speed and temperature is sufficient for each measurement. Only record data over time if there are significant fluctuations.
hg
Herbert.

Hi there,

I only recorded the cold state due to time constraints. Here are the excerpts from the attached Excel file:
time | Zyl1 | Zyl3 | Zyl4 | Zyl2 | RPM | Oil temperature
15302 0.43 0.56 -0.51 -0.47 771 18.4
15630 0.43 0.55 -0.51 -0.47 770 18.4
15835 0.44 0.54 -0.52 -0.47 773 18.4
16166 0.45 0.54 -0.52 -0.47 772 18.4

And here's the area where the car is shaken.

time Zyl1 Zyl3 Zyl4 Zyl2 Z1+Z2.. Revolutions per minute (RPM) | Oil temperature.
83894 0.61 3 -2.04 -1.84 -0.27 1624 18.2
84230 0.84 3 -2.2 -1.96 -0.32 1583 18.3
84436 0.99 3 -2.27 -1.98 -0.26 1569 18.4
84775 1.24 3 -2.43 -2.08 -0.27 1.624 18.5
85099 1.42 3 -2.53 -2.16 -0.27 1.603 18.6
85305 1.54 3 -2.6 -2.2 -0.26 1.608 18.6
85508 1.57 3 -2.69 -2.21 -0.33 1592 18.7
85833 1.78 3 -2.8 -2.25 -0.27 1635 18.6
86159 1.92 3 -2.88 -2.3 -0.26 1582 18.6
86484 2.05 3 -3 -2.31 -0.26 1.605 18.5
86688 2.1 3 -3 -2.33 -0.23 1591 18.5
87018 2.18 3 -3 -2.41 -0.23 1.627 18.5
87343 2.22 3 -3 -2.44 -0.22 1.583 18.5
87678 2.26 3 -3 -2.48 -0.22 1.619 18.6
87886 2.28 3 -3 -2.51 -0.23 1.613 18.6


The MSG is reaching its regulatory limit (sum of deviations > 0.1) and can no longer compensate?

Recommendations?

Best regards,

It's a shame you measured it with a cold engine; it would be more useful to measure it at operating temperature.
From now on, everything is subject to verification - assuming that the Low Load Regulation (or perhaps better, the idle speed control) would still function at 1800 rpm, and that the EGR correction is limited to 3 mg/stroke, then the engine with cylinder 3 would have a problem. This could be narrowed down to the injector, and poor compression would have been noticeable even at low RPM.
My suggestion is to record the data again with the engine running at its normal operating temperature, specifically at approximately 1800 RPM, and save it as a log file. Perhaps you could also record data at a second RPM (1700, 1900).
hg
Herbert.

Hello Herbert,

I now have data for both the cold and the warm (55°C oil temperature) conditions, as well as with slightly higher engine speeds.

At 1800 RPM, it vibrates so much that the engine speed drops to 1600 RPM, even though the accelerator pedal position remains the same.


Best regards,

Hi,
I would have understood "warm" to mean operating temperature.
However, injector 3 is already very noticeable.
I would exchange that one, but I would wait and see about the others.
hg
Herbert.

Hi there,

I'm back to working on the topic. And I'm in a situation that's not quite ideal.

I (somewhat hastily) bought four brand new (04L130277AC) Bosch injectors (at the price of refurbished ones), which are compatible with my engine code CRBC, but according to the list, they are suitable for Euro 6 vehicles. Mine is Euro 5, and the CRBC engine code was available in both Euro 5 and Euro 6 versions (the latter with a NOx storage catalyst and two EGR valves...).

"I had the 04L130277E part installed, which Bosch has since replaced with the 04L130277KE. I have a question for Bosch about whether the 04L130277AC part is backward compatible with Euro5 standards. Unfortunately, the technical employee who was looking into this matter is unavailable for the rest of the week. I likely won't receive an answer until next Monday, and I imagine the employee will probably err on the side of caution."

What do you think? Are they compatible?

The new calibration code is at least accepted by the engine control unit, which I have verified.

I removed injectors 3 and 4 today... they came out without any problems, with just a little bit of gentle prying.

The image from the third one is attached.

Quote:

I had 04L130277E installed, which, according to Bosch, have been replaced by 04L130277KE.

I now have a question for Bosch about whether the 04L130277AC are backward compatible with Euro5 standards.
Bosch...List........ Injector poker }
Why don't you check with VW (AKTE) to see what parts are supposed to be included? Or just try it out - if it works, that's good; if it works for a long time, that's even better.
hg
Herbert.

Hi Herbert,

I inquired with VW... the numbers I posted are VW part numbers. And according to VW, the correct type of catalytic converter (E/KE or AC) depends on the Euro standard and is determined by the engine code.

According to my understanding, the EU6 standard should result in better fuel distribution/improved throttle response, etc. I don't rule out the possibility that the classification is determined at the end of the production line, based on tolerances and accuracy, similar to how processors are classified based on their maximum clock speed.

The injectors are still in their original packaging... I can still return them.

Perhaps someone has already had this experience, or maybe there's even a Bosch MA expert hanging around here?

Best regards,