SPETRUZZI

Mine blows fiercly hot air out the outside vents. I found that if I switch to econ then rotate the dial to hi , then to low then back to my temp setting 70 degrees and hit ac again, the air slowly becomes cool again. Thanks for the info on parts. Sounds like a simple repair. Can't wait to take care of this most annoying problem.

Nedrager

I just swapped the valve on mine. Same issue, outside vents hot center vents cool. I was able to find it much cheaper here at the dealer than anywhere on the web, that was surprising. It's not to hard to change if you have some experience working on cars, it's just a bit of a pain due to where it sits. There isn't a lot of room to get the tools in there to remove the hose clamps. You'll lose about 2 liters of coolant, so plan ahead and buy some beforehand.

SPETRUZZI

Thanks for the heads up. Is bleeding the system hard?

SpeedCrazie

Is there a how to yet for this?

SPETRUZZI

I'm going to take pictures and post if their isn't.

Nedrager

Haven't even seen a how to for this part. I suggest you have a look at the part then find something the right size to plug the lines as you remove them. You also need to keep the valve body plugged as you're removing the houses or it drains through the valve assembly... And put something absorbant under the valve before you start, helps make clean up a bit easier and quicker. You don't really need to "bleed"the system afterwards. All you need to do is start the car and turn the heater on high, then refill the coolant reservoir once you see it's dropped down. I left the cap off the reservoir and refilled as it dropped. It's not big deal to run it without the cap for a few minutes to get the air out of the system, just remember to put it back on when you're done... Good luck, it's not a fun job.

caf

I had this issue last summer on our '05 A6 3.2. Started blowing REALLY hot air from the outside air vents on a REALLY hot day. We melted. Then it got better, but eventually had a couple more episodes.

Pump/valve unit, 4F1-959-617-B was replaced under CPO warranty, so I don't know the actual charge. Problem was fixed, though, and it hasn't recurred. I was out of warranty I'd probably try to fix it myself.

MNblackS4

Has anyone tried to clean up the valve to resolve this issue? Given the TSB states they are now cleaning the engine blocks better to avoid this I'm wondering if there is just debris in the valve that needs to be cleaned out.

ideas?

Gambit7

I'm necroing this thread only because I recently had the same issues. I'm a professional captain/engineer so instead of just replacing things I like to find out why they broke and prevent it from occurring again.

For me, this issue started after having let the car sit quite a while.

Knowing that the pump valve unit was a simple solenoid valve (having worked with solenoids many times before), I surmised that it was possible the solenoid itself was simply gummed up.

So, instead of spending $500 on a new part I decided to fix the old one. Basically all you do is unscrew the hex screws holding the valve unit covers in place (they look like silver tophats) and carefully set them aside w/o damaging the gasket. You'll see the solenoid plungers (silver cylinders) sitting inside the housing; no need to remove them, just work them up and down until you're not feeling as much restriction anymore (add a dab of grease if u need to). You will likely notice some heat scoring on the sides of the solenoid plungers; this is what causes the valve unit to fail and is what you're basically trying to fix. Engine gets hot, solenoid sits in the same place too long and you get scoring.

Anyways, voila. Slap the valve covers back on exactly how you took them off and test it out. More then likely it'll work like a charm.

The "redneck fix" for gummed-up solenoids is typically just to beat the hell out of the solenoid cover. You can try this if you're scared to pop the covers off, but really it's not a hard fix. Just make SURE you dont lose any components, because if you do you'll likely be stuck having to tow your car to a mechanic since you may end up with an open coolant line.

While you're doing this fix you can check all of your wiring, but odds are they'll be fine. If the wiring was an issue I'd figure you'd get a code. Tighten em just to be safe.

And yah, if you wanna know what happens to your old pump after you buy a refurb one for $500, it's essentially what you just did. The parts reseller just cleans up the solenoid. So you just cut out the middleman for $0. Enjoy!

Martinoslav

You should keep searching, guys...

Here is the answer how to fix this issue:
https://www.audiworld.com/forums/sho...9&postcount=40