Blend Door Repair Secret '96 Passat B4V

diesel300dmanual

Active member
Joined
Dec 16, 2004
TDI
Jetta, 1999, Silver
In the event that any others struggle with the poor heat (lukewarm) issue:

Symptoms: foam pieces blowing out of the vents
Problem: The blend doors have lost their foam backing

Note: i found that it wasn't necessary to remove the dash or HVAC.

1. Remove the center console which surrounds the shifter
2. Drop the knee bar down which runs the entire width of the car (2 screws at either end)
3. Remove the stereo and get a screwdriver in there to release two clips that hold the HVAC front cover on. By releasing them, it will begin to split.
4. On the bottom of the exposed HVAC (roughly in back of where the storage bin was on the console), take out the lower bolt
5. Put a wire tie in through that exposed hole (where the bolt came out) and cinch the HVAC cover back towards the seats, exposing the compartment where both blend doors are.
6. Using a mirror and light, notice how many of the holes in the doors have lost some or all their foam.
7. Using sticky back felt (88 cents per sheet at Walmart), cut to size and apply to each door. NOTE: you can adjust the doors by using the control knobs. One adjust the forward (closest to engine) door with the AC-Heat control. The other adjusts with the air selection knob (vent, floor, defrost, etc).

I was able to get my entire hand in there. After ruining a couple of pieces of felt due to it sticking to random things, I was able to get it repaired.

Car heats wonderful now.

Thanks to everyone for their help

Diesel Don
 

r90sKirk

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Oct 21, 2003
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CedarTuckey, Michigan
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All TDI's - No gassers! Luxo-Tourer = 13 Passat (hands down, the nicest car we've ever owned), Most fun = MK4 Golf
Don,

You are the man, thanks for the tip! It's especially helpful for us "dying breed" B4V owners, there's getting to be less and less of us out here.

Ya might want to post this in the A3/B4 section though or maybe a moderator could move it?

Thanks again,

Kirk
 

tdidieselbobny

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Apr 4, 2005
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Stafford,NY (WNY)
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'03 Galactic Blue Jetta TDI, '15 Silk Blue Golf Sportwagen TDI
Thanks!!!!! It's supposed to be decent weather here this weekend,so a good time to try. Do you think the HVAC foil tape would work as well? Maybe I'll grab both on my trip to store this morning.
 

schultp

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Mar 11, 2008
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Michigan
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2010 Jetta Sportwagen, 6sp manual
I'm posting a link to this post over in the A3/B4 forum. Anybody know if this method will also work on the A3 cars?
 

tdidieselbobny

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Joined
Apr 4, 2005
Location
Stafford,NY (WNY)
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'03 Galactic Blue Jetta TDI, '15 Silk Blue Golf Sportwagen TDI
I needed to remove the emergency brake boot,and 2 screws that hold the console in rear seat area also. I recommend using zip tie to cinch the cover back,then cut the extra pc off flush-I figured a wire might poke my skin or eye when I looked into the blend door-I was able to peer into the box w/ light-both doors were cleaned of foam:rolleyes:..... I tried to use the HVAC tape-but that didn't work too well.I then broke open the 5 pack of adhesive felt sheets-didn't even have to use a whole sheet..... I cut a pc. 3"x7" -that fit the first door pretty good,so I test fit it on the inner door-seemed to be ok,so pulled back out and peeled the paper of back-took a couple tries,but eventually got it on inner door-probably could have been cut another 1/8"-1/4" wider,but all holes were covered.First door was piece of cake. Couldn't tell what was causing the heat control door to bind-ended up not working w/ knob,so I rigged a wire w/ loop over arm on bottom(cable popped off of bottom)-cinched it a little w/ needle nose vise grips,then ran the wire into passenger side a little,then twisted a loop.Now the cold/hot is hand control:p.Got it back together,but haven't tried it yet-need to do a couple more things to car,so I left it in garage.I will post back.....
 

Rickstah

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Feb 5, 2002
Location
Yukon, Oklahoma
TDI
NB, 2002, green, Eurotek STG1
If I can follow these directions it will be a great load off my mind, wasn't looking forward to the whole dash removal!

One thing, is the adhesive on the felt pads supposed to resist the hot air in there? The heater in my A3 could make the air almost too hot for the skin, just wondering if it will retain its integrity, or melt? I'm hopeful! So is the final consensus the felt pads from Walmart will work as well as anything, in this particular situation?
 

Mcgink

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Oct 15, 2004
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South of Boston MA
TDI
I-Red,"The Passat formerly known as Harlequin" 97 B4, a non VW GTDI too
Worked great!!! This was an easy fix. I'll have heat when I head north next week.
I'm curious if the blend door fix had a positive impact on your A/C temps as well. I'm thinking that it should improve both since the temp door either blocks off the heater core or sends air through it.
 
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tdidieselbobny

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Apr 4, 2005
Location
Stafford,NY (WNY)
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'03 Galactic Blue Jetta TDI, '15 Silk Blue Golf Sportwagen TDI
I'm curious if the blend door fix had a positive impact on your A/C temps as well. I'm thinking that it should improve both since the temp door either blocks off the heater core or sends air through it.
I forgot to try it Tuesday when temps got warm,but my A/C temps seemed ok this past summer.
 

tdidieselbobny

Top Post Dawg
Joined
Apr 4, 2005
Location
Stafford,NY (WNY)
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'03 Galactic Blue Jetta TDI, '15 Silk Blue Golf Sportwagen TDI
If I can follow these directions it will be a great load off my mind, wasn't looking forward to the whole dash removal!

One thing, is the adhesive on the felt pads supposed to resist the hot air in there? The heater in my A3 could make the air almost too hot for the skin, just wondering if it will retain its integrity, or melt? I'm hopeful! So is the final consensus the felt pads from Walmart will work as well as anything, in this particular situation?
Time will tell on the adhesive-but I have 4 more felt sheets if it doesn't hold up. I tried to put the HVAC foil tape in there,but it stuck together when I tried to place it inside. I guess I could've tried some smaller strips:eek:-
 

Mcgink

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Oct 15, 2004
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South of Boston MA
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I-Red,"The Passat formerly known as Harlequin" 97 B4, a non VW GTDI too
I started this job today on "I-Red" and took some pics that I'll post here in this thread for others to see.

After you remove the center console and knee-bar you can see the screw and clip. (marked red)



And the Driver-side clip



And the clips slide outward from the center



When you pull the cover from the bottom, you can see the mode door (three holes)



Unfortunately, the space you see here is about all you get to work with. I removed the four 8mm bolts (2 each side) from the upper dash to allow the cover to be tweeked open a smidge more. A helper to pull upward/rearward on the lower middle dash gave me enough to get my hand/arm into the heater blend door.

There's not a real good way to get a pic of the blend door so I snapped the pic below by sticking the camera into the access area. You can look at it with a flashlight, but the repair is done kind of blindly by hand /feel.
 
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Mcgink

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I-Red,"The Passat formerly known as Harlequin" 97 B4, a non VW GTDI too
I finished this today. On the blend door, I ended up doing a vertical layer and then a horizontal layer since the seems in the 2" strips were over the holes in the flap. I cut the stips ~2" longer for the horizontal layer, I wanted them to wrap around and stick to the back of the flap on each side. I was able to get my fingers around the right side to make it stick. I couldn't find a way to get my fingers/hand to wrap the left side around so I made a Gizmo :D



It actually worked pretty well at getting the strips wrapped around and stuck to the back of the flap on the left side. I think if I do another one (The Green B4), I will try the 1 piece felt though. Alignment is prob tougher, but easier only having to apply 1 piece.

The mode door was pretty easy since it's right behind the access area.
 

IndigoBlueWagon

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Aug 16, 2004
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South of Boston
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'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
This is going on the to-do list for the B4. Heat is pretty good but I do have to shut the dash vents off manually.
 

Abacus

That helpful B4 guy
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Nov 10, 2007
Location
Nobleboro, Maine
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See signature for TDI's
I did this last night on the B4V I'm selling and have to say "Thank You" to the original poster who came up with the idea. It took me 3 hours from start to finish, including buttoning up the interior.

I originally was going to use the 2" wide heat acceptable foam, but based on Mcgink's post, decided to go with the one-piece foam. I backed it with the metal tape, since that stuff is tenacious, by sticking the foam to the back of the tape so the tape would attach to the door. Then I covered the outside seams with it, so if it did separate, it wouldn't go anywhere. It was not as easy as it looks since when the silver aluminum tape touches anything, it's attached.

It's not pretty, but is very functional and won't be seen anyway.

I did need to remove the radio, which allowed the dash to come up a little more, but not enough to see while your hand is in there attaching the foam.








This was the mode door and the blend door, which is why it had no heat.






And here is the final product. I added holes in the mode door so it would still provide heat/air to other areas despite the selection. I believe this is why the original foam was porous, and using a non-porous foam would stop that effect. The holes I added were a guess, and they are a little larger than they could have been, but the effect is nice. When I want to shut down all heat to the dash, I just close the dash vents manually. It's not a problem or annoying, just more flow than I expected.






When you get done, I HIGHLY recommend vaccuming out the debris you see in the bottom picture. If you don't, you will be covered in it when you turn on the fan. Lesson learned.
 

TDI Convert

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Feb 15, 2006
Location
Ames, IA
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2006 Jetta BRM
^ Thanks for posting and including the pictures. I need to do this to my A4 Jetta. I am going to cover completely with metal tape and foam as you did. Where did you get the one piece foam from?
 

rockymountainwannabe

Well-known member
Joined
Jan 26, 2008
Location
U.S.
TDI
1996 Passat
First of all thank you to all that contributed to this write up. Just did mine last night and the heat will once again melt your skin. I didn't remove the radio and had just enough room. Removing the four bolts(2 on each end of the dash) really helped. I used HVAC tape. Cut into 3-4" pieces and started sticking it on. The smaller pieces made it easier to place more precisely. You can go both horizontally and vertically. I also taped up the lower part of the heater box(from just below the clip on the drivers side to the fastener screw on the bottom) after I put it back together because the foam seal was deteriorated and was losing a lot of air flow there. Had so much fun I told my friend I would do his this weekend. Took just under 4 hours start to finish. Make sure you get all three rows(3 vertical rows) on the blend door. The row under the silver tape in Abacus pictures was hard for me too see, kind of wrapped around the corner. Also, I read an update in another thread by Abacus - DO NOT cut the holes in the mode door felt. Thanks again to all.
 

bherman13

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Feb 26, 2013
Location
Ohio
TDI
2006 BRM 5spd
So I may be interpreting this wrong, but it sounds like there have been a couple different types of foam people have used? Can somebody give a link/picture of what they think is the best choice?

Also, does anybody have any long term positive/negative feedback on the foam they used (how well it's holding up)?

I'm thinking about tackling this some time soon since I've had a decent amount of foam coming out my vents on the B4 I picked up this year.
 

augie dog

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Apr 5, 2012
Location
Apex,NC
TDI
1996 Passat
Is it possible to use a material that could be glued on to door? I am thinking spray or apply glue to door or material then put felt or whatever into place by sliding or positioning material into place. I was having an engine temp issue that was resolved with a new thermostat. I was all excited that I would now have cabin heat but to my surprise it was not enough heat for the 39 deg. morning drive to work. I can safely assume I have the same issue with the blend door. I was getting foam fragments blowing out of vents early on after purchasing the car. I also have to manually close vents when in defrost mode. Anyway looks like I will be tackling this also.
 

BKmetz

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Illinois
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2015 Passat, titanium beige, 6MT
Unless you're hell-bent on making it like stock, you don't have to use any kind of foam on the blend doors. The foam is there so a minimum of fresh air flow circulates in the car when the HVAC is shut off.

Use duct tape, plumbers heavy foil tape, whatever works.

:)
 

GTSLOW

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Oct 26, 2010
Location
Fort Knox, Kentucky
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15 GSW & 04 Golf
I desprately need to do this! All the foam blew out of my vents and now when you close one it whistles like crazy!
 

Turb0

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Oct 26, 2013
Location
Charleston, Sc
TDI
MK4 GLS Wagon TDI
Can anyone verify if the blend door foam issue affects the air conditioning? Recently my foam has passed through the vents and I get the typical low heat. But my a/c is not cooling at all. Everything seems to be operational, compressor kicks on, cooling fans turn on, system pressures were checked, but still no cool air at all. Worked fine last month before I started using the heater. I thought the blend door issue only affected heat, do I stand corrected? Thanks in advance for any information. I was hoping to continue putting off repairing the foam, but if it is my issue, I'll have to handle that ASAP.


Sent from my iPhone using Tapatalk
 

Mcgink

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I-Red,"The Passat formerly known as Harlequin" 97 B4, a non VW GTDI too
I think it has some, but very little affect on the A/C Temp. My temp at the vents changed a couple degrees. It was only noticeable via a thermometer though, it didn't really feel any cooler.
 

Ray_G

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Jul 20, 2004
Location
Tulsa
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98 Jetta TDI
Thanks for the write up. It took me about 2 1/2 hours to do, and I used the Wal Mart felt with sticky back on it. I warmed mine up a bit with my heater before I tried to stick it on. The glue got really tacky and once I had it smoothed out it was stuck pretty well. My only complaint with my car is that with the foam gone the door that controls the air going to the outlets does not seal all the way. So, when you have the air directed at the footwell there is still some air coming out of the dash vents. Not a huge problem, but somewhat annoying. On the other hand I HAVE HEAT NOW!! Thats the most important thing. Thanks again.
 

ToddA1

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Aug 3, 2011
Location
NJ 08002
TDI
'96 B4V, '97 B4, '97 Jetta
I did this today, but I added a step.

I unbolted the kneebar and dash and had the "chest plate" like panel pulled as far as I could. It pretty much looked like Abacus's pic. I was staring into the heater box and was already thinking it would be awkward.

Since I already had the dash unbolted, I decided to pull the airbag, its left bracket and pull the entire panel out. Normally, the upper bracket bolts are impossible to reach, but since the dash was unbolted, I was able to lift it enough to easily get a ratcheting box end wrench in there.

Disconnect the side ducts and the panel easily slides out. A benefit of open access is I was able to vacuum out the rotted foam and get the blow gun in there to blast the doors of any residual foam. I had the vacuum in there at the same time to keep the stuff from going everywhere.

You have plenty of room to clean the doors with solvent to ensure your repair sticks. I used cold weather HVAC tape. I also replaced the foam gasket on the removed panel and vacuumed the rotting foam from the wiring harness.

I figure I spent 30 minutes pulling and reinstalling the airbag stuff, but figure I saved time trying to work around the panel.

This is what you'll be looking at if you decide to pull the panel. The dash is still in the car.




This is the box of deteriorated foam from the heater box and wiring that I pulled with my hands. This doesn't include what I vacuumed out.




-Todd
 
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