Intermittent power loss on Audi 100 TDi (AAT 115 hp)

Hi everyone, I'm new here.

I'm having a problem with my Audi 100 C4 TDI AAT. Occasionally, and increasingly recently, I'm experiencing noticeable power loss above 2000 RPM, similar to what you'd feel if the turbo wasn't engaging. However, I can still hear the turbo whistling. Not excessively, but noticeably.

It seems that sometimes, when I'm maintaining a certain speed in a gear and then want to accelerate, I don't have any power. However, if I release the accelerator, press the clutch, and let the engine speed drop to idle, and then re-engage the clutch to accelerate, the power is fully available again.

I have a chip installed in my car, but it's not the cause of the problem, because the issue still occurs even without it. The error code reading showed: 1 error in the exhaust gas recirculation system, indicating a control difference.

After that, I removed the EGR valve, cleaned it, and checked its functionality. Everything seemed okay. I also inspected the vacuum hose connected to the EGR valve. None of that has made things any better.

What else could it be? Could the intermittent error code that's being read be related to the loss of power, and if so, which specific part could it be?

Thank you in advance.

Chris.

What happens if you temporarily disable the EGR valve? So, disconnect that vacuum hose and seal it with a screw in a way that prevents any dirt from being sucked in and prevents any loss of vacuum.

If it works, the control system could also be given a shot.

Best regards,

Jan.

I haven't tried it yet, but shouldn't there be a different error code in the error memory if the control system is faulty? And wouldn't there always be a performance gap?
Based on my feeling, it seems like a mechanical issue, because after returning to the idle position, the power is always available again.

The control system consists of a valve that converts an electrical signal into a pneumatic signal through pulsed control, which then activates the EGR system. It essentially works with an iron core that is "levitated" by the pulsed magnetic field, causing it to flutter slightly - Ulf once disassembled one of these and described the process in detail.

If this iron core is stuck, then your effects are explainable - the control is working fine, and the valve is also okay, but it's getting too much vacuum pressure due to that particular component, causing it to expand too much. And when the engine is idling, where it is further drawn in, it is then dissolved again because the magnetic field has become stronger.

Try this: it will disconnect the valve from the EGR system, ensuring that it remains closed all the time, regardless of what the computer says. If it's a problem, it's likely due to some AGR components, probably the catalytic converter (which, in my opinion, isn't that expensive).

Regarding the error memory: Since a "defective" EGR valve that has been deactivated won't be registered, I don't think you'll find anything conclusive there.

Best regards,

Jan.

Hello again,

I just tested what happens when I disable the EGR valve... It made no difference. I disconnected the hose, sealed it with a screw, and taped the EGR valve shut where the hose normally connects. But I'm still experiencing power loss. After releasing the clutch and while idling, the engine immediately returns to full power.

What else could it be? The AGR valve is working, which means the pressure regulator is also working. Could it be due to a stuck valve lifter? While I don't stutter, it could be something else, right?

'Exhaust gas recirculation system, control difference error.'

Hello,

Do you have the error number?

The error codes on the printout are:

00560 017

Please provide the text you would like me to translate from German to English.

Exhaust gas recirculation system.
Regulatory difference.
intermittent error
sporadic error
occasional error

hello everyone...

I struggled with the same problem for about half a year...

Together with Falken, who was experiencing a similar problem, we eventually came up with a solution...

The problem was the valve, which is controlled by the STG (Steuergerät - control unit), and the EGR (Abgasrückführung - exhaust gas recirculation) valve, which was being exposed to vacuum/atmosphere... it simply wouldn't open anymore.

Instead of approximately 45, the value for the amount of air being drawn in was always 110... that probably threw everything off.

I replaced this valve with a generic one, in this case an N75 type, and lo and behold, the car runs like it did before... however, I have to admit that the throttle response was more immediate before.

Maybe this will help someone.

Best regards,