I need help with my 1999 Audi A6 Quattro (157,000miles)!!
I got car 1 week ago. Check engine light was on, and tune up resolved situation. 287 miles later check engine light reappeared throwing a new code, P0411. Received outrageous estimate for new air pump, vaccuum hose, and some other hose.
I am concerned about driving the car long term because I was told if i drive it, it will cause my three O2 sensors to go out, resulting in $600 more of work.
I am not naive by far, and got a second opinion. The Air pump itself is $400, but geez i just spent $430 on the tune up and $100 on oil flush/change due to sludginess.
Does anyone have any suggestions or info to help me!!!! Please!!
Thank you in advance!

 

I think the P0411 is considered to be the secondary air pump. If that is true you don't have to worry about it unless you live in a state that has emission checks.
The only thing it does is pump extra air into the engine for the first 30 seconds during a cold start. It will keep the revs a little higher during that time and heat up the engine a little quicker which will reduce emissions.
So honestly the only thing it does is reduce emissions during a cold start. I had mine throw a code for 10k miles until I finally got sick of the check engine light (CEL) and found the main hose connecting to the engine was basically gone. Once replaced with a 10$ autozone hose CEL was gone forever.

I am not aware that this part will damage your O2 sensors. I also looked into taking the pump out completely instead of replacing it (before I knew it was just a hose) but that requires also a fix to fool the ECU in thinking the pump is still there and working.

 

I would check the vacuum line first. In many cases, P0411 is caused by a faulty vacuum hose. Although replacing vacuum lines are pretty straight forward i.e. 45 minutes at the most, if you don't feel comfortable working on the car, then I would negotiate with the mechanic to just replace the vacuum lines first. It will cost you an hour of labor and $20 of parts at the most. If the mechanic is not willing to do that, then take it to someone else.

BTW, o2 sensors are designed to last about 100,000 miles. If the sensors were never replaced, then they will need to be replaced soon.

 

Sheldon, Thank you so much for the information. For whatever reason the two mechanics I went to are trying to dupe me into paying $845 to fix this problem. 1) New air pump for $399.99 2) $179 for vaccuum hose 3) $80 for another hose.... idk I think they see a lone woman trying to fix up a car and are trying to schomooze me over.

Hxgaser!
Thank you for the info!! If i was able to do it myself I definitly would! I am in the process of trying to get a mechanic friend of mine to try and help me! I am praying for it to be a faulty vac hose. I am totally frustrated, i am worried that this car isn't going to be worth my time and money for the long run..... I paid $3500 for it and now have already put in almost $700, with still needed to put on brake pads, get airbag light off, abs/brake light off, and some other stuff the mechanic said i needed like Valve gasket cover, Transmission flush, and engine mount change (even though the mounts are still good).
What happened to honest mechanics anymore!

Once again i truely do appreciate your guys information and help!!!!

 

Guys one more thing.... I just got through researching the sound of the cold start on youtube. My car does not make that sound at all.... it does take a little bit longer to get moving in the morning but there is no awful noise like that? Am I missing something?? Is my water pump really needing to be replaced??? Or is my best bet just to replace the vac hose right now??
I apologize... I just don't want to over pay for service and parts i don't need!!!! thanks a million!!!

 

In case you do have to get the air pump I wanted to let you know our internet price puts that at 299.25 dollars. I do see 2 hoses that connect to the pump. Not sure which one you might need but I see one at 73.50, the other at 59.63 dollars. I'd need your vin # to figure out which you'd need as there were vin splits for your year, I had more than one choice.

I'm in parts, and I'm not sure about the noise issue you said you were looking into but do not have. But a water pump can make bearing noises. A low growling kind of noise, but so can a bad alternator. It's not uncommon for a water pump to leak coolant out of the weep hole that is designed into the bottom of the pump. It's quite likely that if you have a water pump bearing going bad that is making noise it's going to leak on you soon too. Either way it would need replacing. To diagnose where a bad bearing is, whether it's a water pump, alternator or some other accessory, techs usually use a stethoscope and run the engine, touch the tip to various parts and then it's easy to find what part is making the noise if in fact there is a bad bearing in one of the belt driven parts on your engine. If that noise is internal inside the engine, then it's going to be much tougher to find. Good news is, it's usually not internal. It could be a serpentine belt tensioner, or roller. There are belt tensioners and rollers for the timing belt too. If you have a timing belt tensioner or roller going bad, get that fixed asap. If those stop rolling/spinning then the belt that rolls on that bearing will get hot, melt and break in mere minutes. Then you bend valves in the head and things get messy and expensive quickly.

 

I think the sound you are referring too is that horrible grinding/dentist noise that some air pumps give from them before they die. If you don't hear that it either means the pump is already dead or it is working properly but one of the hoses needs to be replaced. It is usually easy to figure out. When you car has been sitting over night, start the engine, walk outside in front of the car and put your head close to the passenger side headlamp (at least that is the location of mine but it's a 2002). Within 30 seconds after the engine has been turned on you should hear the pump go quiet/turn off (it will noticeably change the sound/db). If that the engine sound pretty much remains the same for 60 seconds you have a dead pump and not the hose.

If it is the hose it will be most likely the big one going to the back of the engine. Have your friend check for any damage to that hose and again you can get a replacement from auto zone for like 10 bucks. It won't have the nice Audi rings on the hose, it won't be nicely shaped to run exactly along the body but if you friend is mechanically inclined he will have no trouble getting it connected

 

Thanks Sheldon!!!!!
I have an update!! When I left work at lunch yesterday the engine light was on... came back and finished working. Upon parking on the slope, i slightly scraped the right front area of bumper. so.... When I leave work, guess what... the CEL was off.. I has remained off!!
I did what you said this morning, I cold started the car, You can hear the rev then after 30 seconds the rev stops and the car starts warming up. No weird sounds, I had my ear to my headlight area (i think my neighbors thought i was crazy) and I heard it kick off after about 30 seconds. I am assuming the pump is good.
I also went to a 3rd mechanic yesterday to just ease my feelings, explained that the CEL was off. He suggest that one of the hoses is no good being that on scraping on the incline possible jarred it again into place. He is checking today and said the he will change the hoses out for me if needed. He is going to take off the faulty hose (if it was that) and get one cut and applied for me!!
The mechanic is actually surprised on how well educated i am on my Audi A6. I told him it was thanks to you guys here at AudiForums who have helped to educate me from being a sitting duck!! I'm telling you education makes a difference with mechanics!! They no longer see me as a naive woman trying to fix a car!!! Yay!! Once again thanks!!!!!! I'll keep yall updated!!!

 

Glad to see your issues have been resolved.

Also since your MIL (check engine light) is intermittently turning on and off that means that it is infact a problem with a hose somewhere. That and the fact that you only have one code stored in the ecu. A bad pump will throw 2 codes one for each bank of the cylinders.

And one more thing if the mil comes back on there's no big problem. You will not harm the engine or any other components by driving it with that code. It is strictly for emissions. If you are planning to keep the car I'd suggest to buy a 10 dollar cable called VAG-COM. The software is free and you will be able to check codes and clear them without having to take it to a mechanic. And you can do best things with it such as program the windows to roll down when you hold and press the unlock button on your remote and roll windows up by holding the lock button your remote.

 

Budanhi,
Thank you so much for the information!! I am definitely going to look into the VAG thing!!!
I am getting ready to start a new thread... another issue just came up, but i sincerely thank everyone for all the info on the air pump CEL issue!!!!!