AGR Off: No Gas Response? Troubleshooting Guide.

Hello. A lot has already been written about the AGR (Abgasrückführung) system, but I couldn't find anything that helps me with my problem. Yesterday, I disconnected the hose from the AGR valve on my Bora PD (ATD) and plugged it with a screw. Then I reconnected the hose to the valve. For the first few meters, I thought the car was running better. However, the following problem then occurred: The car no longer responded as quickly as before. Even though I pressed the pedal, it took some time for the power to come. I then removed the screw, and the problem was resolved. What could have caused this?

Hi,

Are you sure that the screw completely sealed the hose? Nothing should leak through.

I had to force the screw into the hose a bit. I think it's completely sealed now. The hose hasn't been damaged either.

I still suspect that the screw didn't seal properly. You mentioned that you reattached the closed hose to the valve, and it's possible that the EGR valve slowly opened due to the very small remaining cross-section of the hose over the first few meters. However, even with strong acceleration, the valve might not be able to close quickly, which would result in noticeable loss of power and spontaneity. Have you checked in your rearview mirror and observed the soot behavior?
I sealed the hose with a large screw and clamp. I couldn't attach it to the valve anymore, but I didn't want to. So far, it's working perfectly.

I can only agree with René, even though the screw looks tight, it probably doesn't seal completely. I recently had the same problem: Initially, a slight vacuum builds up in the valve (at partial load), causing it to open. Then, when you accelerate, the boost pressure goes directly into the exhaust, and the power is lost. After a while at full load, the power returns because the vacuum in the valve decreases and it closes.

Conclusion: Use a thicker screw, or use the often-mentioned metal plate to create a non-visible closure for the exhaust gas recirculation system near the valve.

Regards,
Sure, here's the translation:

'Hey guys' or 'Hey everyone' (informal)

Thank you for your help. You were, of course, right. It's working perfectly now.

Hello.
I don't understand what you're trying to achieve by closing off the vacuum hose to the EGR valve; you're only making the exhaust behavior of your engine worse and risking premature failure of the catalytic converter due to the high amount of soot (it will become clogged, and then you'll have achieved exactly the opposite of more power ).
During the acceleration process, the EGR valve is closed anyway, so it doesn't make a difference if you close it. Furthermore, in the partial load range, you won't even notice if it's working.
Best regards,
Hanomag2001

PS: Please send me a dynamometer test report, once with the EGR valve closed and once in the stock configuration, and then I'll be happy to reconsider my opinion.

Hi Hanomag2001,

Deactivating the EGR system causes the engine to only draw in air during partial load operation, instead of a mixture of exhaust gases and air. The result is that you produce LESS soot! However, the levels of nitrogen oxides increase, and this unauthorized modification can lead to the loss of the operating license (ABE) due to its impact on pollutant emissions.

Your argument is fundamentally flawed from the very beginning.

Best regards,

Jan.

Hello Jan,
'Sorry, I got something mixed up there. Of course, NOx emissions increase, but I haven't seen any increase in power compared to when the EGR valve is working correctly. The EGR valve was introduced in the early engines, which already had a continuous minimum exhaust gas recirculation system.'
Best regards,
hanomag2001

more power, no, but lower consumption and significantly better turbocharger response .

CU Gremlin.

Hello,

hanomag2001 wrote:

The issue with the EGR valve arose in the initial engines that already had a constant minimum exhaust gas recirculation system.

Please familiarize yourself with the AGR (Agricultural Research) article before writing anything about the topic.
Your statement is simply incorrect; there is no TDI engine with a constant minimum exhaust gas recirculation. I'm just going to say that there isn't any engine that does that.
Okay, but please don't start talking about the crankcase ventilation system... it vents into the intake manifold because otherwise the oil mist would leak out onto the road.

Best regards, Rainer.