Temperature blend door does whatever it wants

So heres the deal... last spring I noticed I was having trouble changing from heat to AC and the other way around. I figured it was something with the temperature blend door and I didnt really worry about it because it was getting to be nice out anyway so I just drove with the windows down all summer. Recently I actually took it in to our local mechanic to find out what was really wrong with it and see how much it would be to fix. He looked at it and told me it was definitely the temperature blend door and the only way to fix it would be to totally remove and replace the heater box out of the dash, and he told me it was going to run about $1200... I was more than a little surprised with the cost. Well its September now, and in Nebraska it can start getting cold late September-early October and I'd really like to get it fixed so I can have heat this winter.
Has anyone else had this problem with their car?
Does anyone have a shop or know of a shop that can fix it cheaper?
I'd even be willing to make a little road trip if it meant saving a few hundred dollars!
If anyone knows anything about it please let me know.
Thanks
-Fred-

The biggest part of the job is removing/reinstalling the dash. I have done it myself on a MKIV, took a total of 6 hours. Might be something to consider - you can remove the dash, have someone repair the heater box and then reinstall the dash yourself.

see these first.
http://forums.tdiclub.com/showthread.php?t=180593
http://forums.tdiclub.com/showthread.php?t=222830

I read your other posts about it and it seemed easy enough so I took off the little panel by the gas pedal just to take a look for myself. Once I got my bearings for what exactly I was looking at I was kinda surprised... the little tab that my mechanic told me had "broken off" was still there attached to the arm. And the cable looked just fine too. The only thing that looked kinda off was where the arm actually goes inside of the heater box. It looked like it was sticking out further than it was supposed to be, and once I got my hand in there and touched it I could tell right away that the entire arm had kinda just fallen out and wasnt even attached to the blend door anymore. I played with it for a little while and I got the arm to clip right back into the heater box and reattach it to the blend door. I took the car for a quick spin to warm up the engine and played with the controls and everything seems to be working just fine! I now have nice cold AC and some nice heat coming out for the first time in a while.... and it DIDNT cost me $1200!!! THANKS "sdeck" for pointing me in the right direction! It took maybe 15mins and it was FREE I took a pic, its not the greatest, but its there haha.

Yep, that is the same as mine and a few others. seems to be a once-a-year issue on mine. You may need to redo it in a few months. Never have found a part number for that insert about the arm. Your mechanic may have meant the tab on that peice. I know one of mine is broken off, but the remaining one usually holds in in place for a while.

Ugh... Mine came out and I can't get it back in. I've tried having the temp control in several different positions, and even with a fair amount of force behind it, I can't get it back in. :-(

first, check and make sure the cable is still attached and working. If not, you can turn the knob all day and it won't change the position of the insert. What I did was push the insert up into the hole while turning the temp bland knob from one end to the other. I think it took a couple of tries. If all else fails, it may be that the actual flap is too far in one direction or the other. try running the A/C on full blast to see if the airflow will move it. When mine failed, I could get cold air on the lowest setting intermittantly at idle, but as soon as the air flow went up it would go hot. Suggested to me that the flap was loose....

My '89 Jetta and'90 Corrado had crappy heat/AC preceded by black foam pieces flying out the vents. Pulled the dash on both and attached thin card stock to the blend doors and that took care of it. VW covered the door with foam to allow some bypass through the doors. The doors have several holes in them.

It does take about 6 hours to pull and install the dash plus empty/fill the AC freon if you remove the heater box.

Good luck.

Blend door repaired: 2 hrs labor $8 part vs $1,500+

It is truly amazing how this and other forums can save the DIY VW owner thousands. I, too, had my AC go to full hot during a brutal August afternoon in Gerogia. What was going on?

The local import shop informed me that the "blendor" as they wrote on the estimate was "broken". They told me the entire dash had to be removed and the Air Distrubution Housing $450, Heater Core $150, Evaporator $300 would need to be replaced, AC charged and $600 labor. Total cost around $2,000. I thought i didn't have any other options.

I found this post at VW Vortex that helped me fix this problem in addition to the posts here: http://forums.vwvortex.com/showthread.php?4445527-DIY-Heater-Air-Conditiong-Fix-(blend-door-issue)
The part you need is called a "Pin" but it's really a plastic bushing with two cheap plastic tabs--one of mine broke and it fell out of the housing. The part number you need to buy is 1H0 819 136
World Impex sells it for $7.98 i believe.

The most challenging part was working in a very confined area. What i can't get over is either the laziness or plain ignorance of repair shops that won't make the effort to fix this with a $8 part. Screw them. Good luck to all of you fixing this problem. My dowel trick that is listed below was my key to getting the metal tab on the blend door alligned--it's very hard to get centered and it does need to be centered within .040" or so.

Here is how i did it:
1. To make the job easier, I removed the passenger seat. Take care wtih removing the airbag connections and be warned that removing the seat will trip the airbag light on the dash. Make sure you have a vag-com to reset when you are done.

2. Using a small, circular mirror that's adjustable (a must for this job) i noticed that the metal tab at the bottom of the blend door was not centered. I also needed to figure a way to know the orientation of that tab for lining up the replacement bushing "pin". So, i bought a 3/8" dowell at Wal-Mart, cut it to about 1.5" and then cut a slot in the top about 1/4" deep and beveled both sides. The kerf of the jigsaw blade was about .020" bigger than the metal door tab and worked perfectly. Draw a black line from the slot down each side so you have a reference as to the position of the blend door. Insert the dowel in the hole and orient the metal tab. I made a mark on the housing wtih a white marker for reference. Make sure the door is centered and then gently slide the bushing in place.

3. For my Jetta i used a 6mm combination wrench to undo the screw at the bottom. Didn't have enough room for anything else.

I also had the carpet and soundproofing out of my car on the passenger's side due to a leaky sunroof drain--not sure if that was critical to performing this job. It might be a bit harder wtih the carpet.

The key is patience to line up the blend door and also make sure you are comfortable while conorted in the passenger foot well. Good luck!!

Used two post between the arm and took a piece of sheet metal to help hold the arm up.

Its actually quite easy to just pop it back in there. Just stick your hand under the side of the middle dash from the passenger side. feel around while turning it from hot to cold and you'll feel the arm. just push it back into place and turn the know back and forth and it will eventually pop back in. Takes 5 minutes

Hey does anybody have a pic of what the top of the insert looks like, I pulled mine and reinstalled it but can't get it to switch to cold. I don't see any broken remnants on the top, is it just a matter of getting aligned properly?

Mogwin said:

Hey does anybody have a pic of what the top of the insert looks like, I pulled mine and reinstalled it but can't get it to switch to cold. I don't see any broken remnants on the top, is it just a matter of getting aligned properly?

Click to expand...

you have to get the "bushing" (pin) lined up with the blend door. fyi you can buy these here.

http://kansascitytdi.com/tdi-parts-for-sale-new/