Ok so car has been throwing P4011 code for quite a while, had it at my tech and he tested the whole system for leaks and found nothing. He also could not do anything to get the Air Pump to turn on, so diagnosed it as the air pump needing replacement.

I finally found a good deal on a part and ordered it in, but while changing it out today I ran into some issues. When I detached the hoses from the pump, water came out of both of them, probably ~3oz. Also, after getting the pump out, I noticed it was heavier than the new pump, and when you shake it around you can hear water sloshing inside. I'm assuming that there should be no water at all in this system and won't be putting the new pump on until I figure this out.

So....ideas? What's wrong and where should I look?

 

I have the same code right now but I also have an O2 code so I think mine is O2 related. But, I researched and checked the SAIS just in case to make sure it was working correctly. I've read two different things. I've read that water can get into the pump because it is positioned so low on the car. I've also read that if your combi-valves are stuck open, exhaust gas can back feed into the SAIS pump then when the gas cools it creates condensation in the pump. I'm not sure about either of these. However, since you have your pump off you can easily check if your combi-valves are stuck open. With the engine off, blow air into the hose that goes from the pump to the front of the engine. If you can't blow through it, the valves are closed as they should be with the engine off. If you are able to blow through it, either your combi-valves are stuck open or there's a leak somewhere between the pump and the combi-valves.

 

its probably just condensation. if the pump were running, it would ge pumped out and it wouldnt build up

 

i also have the same problem with my car. p0411 and a o2 problem . i havent done anything yet i havent checked the combi valves or the pump. just havent had time but thanks for that little write up on how to check the valves. if i get sometime this weekend i will do that

 

Thanks for the tip, gonna try this out and see what happens. Really hope it's just the pump that's fried and not something else

 

True. If the pump stopped working and the combi-valves were working correctly, when they opened it could allow exhaust gas to back feed into the SAIS pump.

 

I had p0411 and it went away after I did my vacuum lines. Check those first before you go ordering expensive pumps/valves.

 

re: bold section in original post

 

Still, at least inspect them. Look for kinks.. Just cause there aren't leaks or he didn't see the leaks doesn't mean anything.

Think about it.. If you haven't replaced them their at least 11-12 years old by now. Cost less than 10 dollars and an hour of your time.

 

I'm agreeing with this My 01.5 A4 has the same issue. Been throwing the same trouble code for about a year and a half and it's now time to smog it. So while I had the front end off to do the timing belt I pulled the hose from the SAIS pump to check for cracks and it was full of water to the upper connector. clear water but had a strong fuel smell to it. Im thinking exhaust gas and condensation after the pump died. Been running like this for the past year and a half, so a LOT of water built up. More than comfortable with...

On a side note, I haven't found any boost leaks, but I am showing 10psi at the gauge (used to get 12). (I did replace all lines within the past 4 years). Hopefully it goes up with a new pump and that settles it...