v6 2,5tdi-AFB / sägen bei Gasannahme? | Posts 16+

Could it also be a faulty regulator in the ESP system, or perhaps the ESP system itself is malfunctioning?

Is there anything new here? I'm interested. Thanks.

Hi,

Unfortunately, not yet. But it seems to me that the rattling is getting worse. However, this only happens when accelerating! When the vehicle is idling, for example, rolling without touching the accelerator, the engine runs smoothly. I think the problem might be related to the diesel injection system (pump, injectors, etc.). What do you think?

Regarding the hydraulic lifters, I will replace them if I have the time, as I can clearly see that some are no longer maintaining pressure properly. However, I don't think it's directly related to the sawing sound (only when accelerating), otherwise the engine would continue "sawing" even at idle. Best regards.

Hello,

"I have some new information: Today, the vehicle went into emergency mode. Initially, there was a very rough combustion noise in the partial load range, which then disappeared. After about 30 km of driving, the vehicle then went into emergency mode. Error reading:"

0550 - Injection start control/Regulation limit exceeded.

This error reappears immediately after being cleared. I don't see any air in the transparent diesel line. This could have several causes. Perhaps the tensioner for the timing belt is stuck? Or maybe the EP (electric pump) is failing?
How should I check something now? Thank you.

I understand your assumptions. There's also the needle valve, could that be the culprit?
Unfortunately, an ESP (Electronic Stability Program) is quite expensive, and you wouldn't just replace it on a whim. However, in this case, isn't it very likely to be the problem? Or am I wrong?

I doubt it's NHG. If it were, the effects wouldn't be so extreme.

I would check the timing belt on the ESP (Electronic Stability Program) and its tensioner.

Regarding that saw, it reminds me that mine does the same thing in the winter when it's cold. I start it, and it runs at a higher RPM, about 1100 RPM, then it slowly decreases. Around 1000 RPM, it starts "sawing" (oscillating about 50 RPM up and down). After that, it naturally drops further to about 900 RPM (idle) and then runs normally. If I give it some throttle in between, it doesn't cause any problems and it responds to the throttle without "sawing," without any issues. It only "saws" when the idle is elevated (between 1050 and 950 RPM).

Hi,

Currently, my vehicle is constantly running in "limp mode." The engine speed is limited to only 2800 RPM. And the error code persists.

I haven't had a chance to check the valve timing yet. Can I check it using VAG-COM in the basic settings mode? Or do I need to manually check the valve timing to determine the cause of the fuel injection problem? Thanks.

Hello,

I just quickly went to the car to check the fuel injection start using VCDS.
Sure, please provide the text you would like me to translate from German to English.
Coolant temperature at approximately 80-85°C:
In the default setting mode MWB 4:

1.2-1.4° after Ot, early spring.

2.0-2.2 °after Ot, late.

It should fit perfectly, right?
Can I use this to rule out the need for checking the valve timing with a timing light, or is it always necessary to perform that check?

Could someone possibly tell me if the value is correct or not? Thank you.

The default settings of the NW (injection control unit) are independent of Block 4. If the default settings don't work, the pump can still be adjusted to match the engine, but this will result in incorrect valve opening times.

I can't comment on the basic settings, as I only have the shareware version. However, you can also do a test run and compare the desired and actual values, as well as the control mechanisms.

Hi,

I've checked everything now (air, etc.).
I think I'll probably have to replace the fuel injection pump. I hope that solves the problem. The pump is still the original one, as it has a date stamp from 1998 on it.

Me again.

I have now read the electric pump in the MWB18 again, and the following results were obtained:

00001000 - Fuel injection pump status.

That means there's a 100% chance that the fuel injector is defective.

I will let you know how it went after I install the new pump. Best regards.

Hello,

I finally had some time to install the new EP. When I removed the timing belt for the pump, I manually rotated the pump. That's when I immediately noticed that something loose was inside the pump (it sounds like a ball?). However, I'd like to open the pump sometime to investigate the exact defect.

Okay, short update: My vehicle is running perfectly again! The pump replacement cost me €1100, including labor.