First off... Great forum!!

I have a '98 A4 2.8 Quattro

About a month ago I had my secondary air pump start making sounds like a jet engine in the morning... so I replaced it..... about a week later I get a CEL .... P0411 code ...Secondary Air System: incorrect flow detected. I have checked the hoses to and from the pump... still tight and no cracks that I could find... I cleared the code, and 3 days later the CEL is back on and the same code. I have verified on cold starts the the pump is actually running ( its so quiet now I can hardly hear it). Now after reseting a second time it is back so I consulted with a local Audi repair shop.
They checked all the vacuum lines and said that they would replace all the lines to start.... ( I have 101k miles on the car) So I have replaced all, and I mean all of the brittle old lines on the car!! I had asked them about other possible things that could cause this, and they brought up the pump that I have already replaced, the solenoid for the combination valves and the combination valves themselves.. They stated that it has been rare for them to have to replace the combination valves or the solenoid.

Has anyone had a similar experience with this and what was the outcome??? Any other suggestions??

 

I guess no one knows....... or has any other ideas....and yes i did use the search button... most of what i have found relates to the 1.8t!!!

 

Looks like I am talking to myself... but I may have figured this out.... It looks like I have a damaged electrical connector on secondary air pump. It looks like it only had partial contact and melted a little.... I hope that replacing that connector has solved the problem!!! I will let you know in 3-4 days!!

 

I have a 00' 2.8 that has been making the "jet" noise on start up for about a month now. Like you, it is the smog pump, but I don't have a lot of time right now to replace it. How bad of a job is it, I think I read the bumper has to come off. Is that true?

 

Yes you have to remove the front bumper, even though it sounds intimidating, it is really easy!!!2 bolt, 2 screws and pry out of side brackets... however, i think they over simplify the removal of the pump itself.... I needed to loosen some of the brackets etc.... (it is a tight area were it is located) At the dealer, the pump was about $290. I picked up a used one for $125.

Now it is so quiet I don't even hear it.

If you need instructions on the bumper removal I can get them to you!!

 

Yes please. Any help would be much appreciated. Or could you point me in the correct direction to find how to remove it?
Thanks

 

I would need to email you the instructions!!

 

Let me know if you need anything else!!!

 

I have a 2001 A4 1.8T that is giving me the same error codes and making the jet engine sounds on start up. Is the smog pump located in the same area as the ones discussed in this post? If so, I would like the instructions on how to remove the bumper and where it is located. I haven't had it in the shop yet. I like to try to fix these problems my self if I can.

 

I looked on Bentley and it says that yours is located under the air box in the engine compartment... lucky you no bumper removal!! looks like you have to remove the belly pan though.