I just bought this car and decided to do regular maintenance on it has two hundred twelve thousand miles on it. when I replace the air cleaner the old air cleaner was really filthy so I put a new one in a few days later I needed to change my mass air flow. when I open the airbox my air filter was soaking wet I thought because the water was getting in from the rain after pulling the Box apart I realized that would be really hard to do because the air goes in on the bottom of the Box not through the filter on the top. I then decided to order a new diverter valve and when I pulled the old one off it was full of water. the car runs fine has a check engine light I thought was the mass air flow the new mass air flow did not fix the light there is no white Vapor coming out of the exhaust and there is no coolant in the oil where could this water be coming from? I'm pretty sure that the water is coming from the cooling system but I'm not a hundred percent because I flush the cooling system out it had really nasty green grey coolant in it.. I filled it up with pure water for a couple days so the driving woodwork the rest of that nasty coolant loose so the water on the air cleaner and in the diverter valve was clear but I'm sure if I had coolant in it it would be the color of the coolant. I'm new to Audis and any help would be great.

 

First thing is first, take the car to your local AutoZone, Advanced Auto, or Oriellys and have them do a Check Engine Light on your vehicle when they give you the codes that are being tripped, you can look up what they are, as well as probable causes and fixes here... Category:Fault Codes - Ross-Tech Wiki Secondly, I do not believe that the coolant runs through any part of the crankcase ventilation system or the boast/ vacuum hoses, the only thing I could possibly think of, would be if you have a bad head gasket, (w/o smoke out of exhaust unlikely) or perhaps a bad valve cover gasket, or some kind of gasket where your getting coolant running into vacuum. I for one would suggest that you clean and tidy up all the vacuum lines that you can, reinstall and then fill up the coolant, and see if the coolant is disappearing after a few drives (its easiest to mark your coolant take with a marker on the outside to know where its at- also best to mark and check when cold- warm coolant will expand) Most likely cause IMHO is that the vehicle sat for a few months if not longer and depending on environment, the vehicle became saturated with water vapor.. But with the P-codes for ur CEL and the coolant check you should be able to pinpoint and isolate a possible cause.

 

Make sure the air filter box is correctly mated together and sealing around the air filter edges. It's possible for some of them to get misaligned or not completely closed allowing gaps to exist where the two halves of the box clamp together using the air filter as a seal. If it's raining when you drive it, it can and will pull water into the airbox from the suction and get the filter wet.

Also, when the check engine light comes on, take it somewhere and get the codes read before throwing $200 MAF sensors at it. They will read them for free at the places gearhead mentioned above. The OBD codes will tell exactly what sensors are reporting issues.