Octavia 1.6 Cayc Nails

Hello!

"I'm experiencing a problem with my Octavia 1Z 1.6CR CAYC engine: it makes a noticeable knocking sound at low RPMs. It's most audible after shifting gears, when accelerating between 1200-1500 RPM."
There's no noticeable stuttering or loss of power, it's just the rattling that bothers me.

Skoda informed me that the injectors are faulty. I performed a fuel return flow measurement, and all four injectors showed the same amount of fuel being returned.

The values for the idle speed control would be:

1 cylinder, +2 mg.
2 cylinders -0.5
3 cylinders -0.86
4 cylinders + 1 mg.

The first cylinder is out of sync.

I believe the current software version is: 9972.

Address 01: Engine Control Module (J623-CAYC)
Label file: DRV\03L-906-023-CAY.clb
Part number SW: 03L 906 023 AG, Part number HW: 03L 906 023 AG.
Component: 1.6L R4 CR turbo diesel H23 9972.
Revision: --H23--- Serial Number:
Encoding: 00114016032400080000
Operating number: WSC 38940 001 1048576
ASAM Dataset: EV_ECM16TDI02103L906023AG 003011
ROD: EV_ECM16TDI02103L906023A_VW32.rod
VCID: 6BD1975582AA6C66BB-803E

Does anyone have more experience with the injectors?

Hello...

Could it be that one of the injectors is failing and performing even worse than indicated? Shouldn't the long-term fuel trim (LTFT) value be close to zero, rather than 1.64 like you have?

Or is it just the usual problem with the 1.6 injectors again...?
Does it start normally?

Sure, here's the translation:

"SG" can have different meanings depending on the context. It could stand for "Spielgemeinschaft," which is a German term for a sports club or association that combines players from multiple teams or organizations. Alternatively, it could refer to "Säkularkantor," a type of church musician who does not hold religious beliefs. Finally, "SG" might be an abbreviation for "Sonstige," meaning "other" or "miscellaneous."

Quote:

1 cylinder, +2 mg. 2 cylinders -0.5. 3 Cyl -0.86 4 cylinders + 1 mg

The sum of all offset values always results in zero. Simply take a Screenshot in VCDS or click the "Save" button in the program.

Best regards, Rainer.

Attached is the image.

It results in a sum of 0.00 mg/H. Consequently, the initially reported values were not actually correct.

The values are within the acceptable range. Regarding the noise levels, there were indeed software updates for the 1.6 TDI engines, but your software version appears to be quite up-to-date.

What exactly is the problem, and is there an audio file of the hammering sound?

Best regards, Rainer.

dieselschrauber wrote:

It results in a sum of 0.00 mg/H. Consequently, the initially posted values were not actually correct. The values are within the acceptable range. Regarding the noise levels, there were indeed software updates for the 1.6 TDI engines, but your software version appears to be quite up-to-date. What exactly is the problem, and is there an audio file of the hammering sound? Best regards, Rainer

The engine control unit (ECU) has been updated to the latest software version, and then a small-batch adaptation process will be performed. According to the diagnostic tool ODIS, all injectors are outside of their specified operating range.

I will upload the audio file soon.

Best regards.

Chris.

Normally, there's a policy of goodwill where defective ODIS units should be replaced.

What are the injector timing values?

Background:
I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.

Best regards, Rainer.

Hi.

I can't find the injection timing data (multi-point working behavior).
Do you know which ones those are for the PCR 2.1?
Are these piezoelectric injectors?

I think you can skip that, because there are no reference values available.

chli1976 wrote:

I think you can skip that, because there are no reference values.

But perhaps there are comparable values available for CAYC engines that don't exhibit the same knocking issue?
If he doesn't look, there will never be any, .

It's an old thread, but I have a question about it, since my family owns the same engine.

Does the knocking sound caused by faulty injectors on this engine always only occur in the lower RPM range, or also in the higher RPM range?

As I understand it, you can't always rely solely on the measured values, such as return flow measurements and data from VCDS. I also lack the experience in this area.