How to: Replacing 2012+ NMS Passat heater core

jjblbi

Veteran Member
Joined
Sep 27, 2000
Location
lbi, nj
TDI
2014 Passat SEL TDI
Had core replaced and connector recall done yesterday, cost to me zero. VW reimbursing Toms River VW $633.00. No hassle, great service. Other than free oil services, this is my first dealer visit ~100k miles.
 

Booth44

Active member
Joined
Jul 21, 2015
Location
SW Ontario
TDI
2013 Passat SEL
Had core replaced and connector recall done yesterday, cost to me zero.
Same here in Canada.

I tried to turn on the heat on the first cold day of fall only to realize that there was zero heat coming out - even on the driver's side. Took it to my local dealer. No questions asked - heater core replaced completely free. They also did the connector that jjblbi mentioned - so a nice bonus, as I had some intermittent CELs thrown from that.
 

eugene89us

Veteran Member
Joined
Mar 17, 2014
Location
Southern USA
TDI
2014 Volkswagen Passat TDI SEL Premium
Part Number Variation

Quick notice: had my heater core replaced today with just under 49K miles. Noticed the new heater core has a sticker with part number ending in A (like the old one). The invoice of course had it ending in B. In OP's post, the new core has a label that also ends in A. Should I be concerned? Why is this variation? I was hoping to get a redesigned core, now I feel the dealership used old part number that was original and will clog again. How do I tell?
 

jason_

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Joined
Jun 2, 2014
Location
michigan
TDI
2015 s wagon dsg
Honestly I think the g12/13 can't take the heat from regens. It's breaking down and plugging, or reacting with the material the cooler is made out of/assembled with.

Several have posted with only dealer visits, dpf still in place, and have plugged cores.




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eugene89us

Veteran Member
Joined
Mar 17, 2014
Location
Southern USA
TDI
2014 Volkswagen Passat TDI SEL Premium


Here is the sticker photo I referenced on a new heater core. Can anyone else confirm the same or different part number on sticker?

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YukonLT

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Nov 28, 2012
Location
N/A
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2010 Golf TDI 6MT
Honestly I think the g12/13 can't take the heat from regens. It's breaking down and plugging, or reacting with the material the cooler is made out of/assembled with.

Several have posted with only dealer visits, dpf still in place, and have plugged cores.




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I think you might be onto something.
 

jason_

Veteran Member
Joined
Jun 2, 2014
Location
michigan
TDI
2015 s wagon dsg
Well, facts are there. G13 is a drop in replacement of G12, and 12 never gave issue prior to dpf bolt ons. Aluminum heads and blocks have been around. Aluminum heater cores have been around.

Only real difference is tremendous heat involved to smoke soot into ash, and that heat is a buddy to either chemical break down or chemical reaction happening with the assist of heat.

Honestly when I swap my core, I'm going to 5 gallon bucket the core hoses separately and run engine until fully flushed with good ol green Prestone. Let the water pump do the work.


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jason_

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Joined
Jun 2, 2014
Location
michigan
TDI
2015 s wagon dsg
This was before I replaced it.

Idling, 29*F out side, Blower on high, temp dial to max, during a regen, water jacket bobbing 107*c...




Can I say, no flow? I'm not quick with metric temps, but 16 isn't high on the scale for creature comfort

Now holding my fingers near a vent, so much heat it makes the skin itch. I love it.

Sent from my S-Off'ed HTC One...
 

Jesse_Boyer

Veteran Member
Joined
Aug 16, 2007
Location
Sioux Falls, SD
TDI
I'm all out...
My 2012 passat unfortunately had the clogged heater core issue. At first I thought it was going to be very costly or labor intensive to fix but after some research it turns out its not a dash out procedure on these cars and is actually relatively easy and cheap to do yourself. I did mine start to finish in about 3 hours.

Heater core PN: 561819031B

Seals and clamps PN: 561898380

Car was at 77,000 miles. Build date 04/12. Climatronic dual climate control. G12 coolant was the factory fill and had only been serviced with G12 until now. The core is clogged with thick white buildup. It may be white rather than the pink that some have reported because I flushed it before removal.

The core exposed. Remove the clamps and pull the lines apart. This was the hardest part. The manual tells you to loosen the 6mm screw that is in between the heater core lines under the hood. It is recessed in a hole between the coolant lines. It must aid in allowing you to move the lines off of the core. It was still tough to do even with it loosened. The bolt is somewhat hard to get to under the hood. I left the lines under the hood hooked up and just drained the coolant at my block heater because it was a lot easier than messing with the lines at the firewall. The pipes leading to the core stay attached and the connection is made where you see the clamps in the pictures. Make sure not to cut the new o rings when trying to reinstall the lines. I bent the lines on the old core to remove it but the new one took more patience as I didn't want to bend it much. The flanges on the pipes kept wanting to cut the o rings as I worked the heater core lines past each other. It would be wise to do a leak check with engine running before reinstalling the trim.

A tip to get the flanges fully seated on the heater core so you can install the clamps. I went under the hood and pushed firmly multiple times on the hose connections to try and seat the pipes onto the core. I also took a rubber mallet and small piece of wood and was able to catch the rib on the line to knock it into place. The lines in the car just don't seem to give a whole lot. Just be very careful not to use too much force when "forcing" things! The lines are just thin aluminum after all!
The core removed. It pulls straight out once the lines are off. I didn't get much coolant out of the lines after I drained the car. This catch can was plenty large enough. Cover the area with rags to catch any other spillage when pulling apart the lines.

Info note: the electric auxiliary heater grid sits directly in front of the heater core and slides out like the core.

Heat works great with the new core. Both sides are HOT on Hi setting and high blower. Decent heat starts being produced with the engine at 145 degrees
I was able to find the core for $74 and the seals for $14 although you could probably reuse the clamps and o rings if you had to. I purchased mine from ecs tuning.

Can you help me with the infamous 6mm bolt that holds the coolant lines to the firewall? I can't seem to find it so I can't get the heater-core to slide out. Any help is extremely appreciated.
 

YukonLT

Veteran Member - TDIClub Enthusiast
Joined
Nov 28, 2012
Location
N/A
TDI
2010 Golf TDI 6MT
Can you help me with the infamous 6mm bolt that holds the coolant lines to the firewall? I can't seem to find it so I can't get the heater-core to slide out. Any help is extremely appreciated.
It's right in the middle between the two lines in the rubber grommet. You can't see it easily and have to just stick the wrench in there and feel for engagement.
 

BKmetz

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Staff member
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Sep 25, 1997
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Illinois
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2015 Passat, titanium beige, 6MT

jolvi1

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Sep 27, 2015
Location
Southwest MO.
TDI
2012 Passat TDI SEL
Hey had a Baretta GTU and first bit of instruction "Jack up front of car" well the heater core hoses are so far down into the engine compartment only reachable from under car.
 

HockeyFan1972

New member
Joined
Jan 5, 2017
Location
Wisconsin
TDI
2012 Passat TDI SEL
TDI SEL as well?

Hi,

AWESOME Post and great pics! I have recently had this issue with my 2012 VW Passat TDI SEL (Automatic). Drivers side blows hot as hell, Passenger side is ice cold. in -5 degree weather, car gets maybe tepid warm.

I have been looking all morning on how to change the Heater core OR Flush the core.

QUESTION: Is my '12 Passat TDI SEL somewhat the same as your pictures?

I vaguely verified thru VW dealer that my car is the same setup as your pictures (Minus the clutch pedal) but they were kinda cryptic about it "Sliding out", wanting me to "Bring her on in!" but i really dont want the bill and im out of warranty.

I am mechanically inclined, and can do most DIY stuff to cars, so if these pictures reflect my car, then this looks a HELL OF ALOT EASIER than removing the dash and such for $1000.00+ the dealer said it might take to fix.

Thanks!

Felix
 

roni024

Veteran Member
Joined
Mar 31, 2007
Location
Syracuse, NY
TDI
2015 Passat TDI SEL DSG
Has anyone thought of or tried to flush the heater core with a solvent? Flux is typically greasy. I wonder if you could cut the lines to the heater core and plumb in a pump to circulate, say, alcohol. Then, install couplings and splice the hoses back together.
 

HockeyFan1972

New member
Joined
Jan 5, 2017
Location
Wisconsin
TDI
2012 Passat TDI SEL
Also, i have re-read this thread 3 times. Does anyone know WHY the drivers side stays hot but the passenger side goes cold? Thanks!
 

Rico567

Top Post Dawg
Joined
Jun 13, 2003
Location
Central IL
TDI
2013 Passat TDI SEL Premium (Turned in 7/7/18)
Also, i have re-read this thread 3 times. Does anyone know WHY the drivers side stays hot but the passenger side goes cold? Thanks!
Someone explained this in another post, somewhere in the several threads on this subject. It has to do with which part of the heater core plugs up first. As it happens, that's the part that's going to blow air to the passenger side. I think there may even be a diagram of the heater system posted as a pic somewhere.
All I know is our car did the same thing when the heater core started to go out. We drove to VA over the holidays, my wife having a couple of blankets on her legs. Overall, though, we were lucky that the heater was still putting out enough heat overall that the inside of the car never became uncomfortable, nor did we have any issues clearing the windows. The dealer replaced the heater core today under the extended 10/120 warranty, and the car is toasty warm again.
 

HockeyFan1972

New member
Joined
Jan 5, 2017
Location
Wisconsin
TDI
2012 Passat TDI SEL
Thanks!

Thank you for that reply. I guess it makes sense.

So i got a quote from my dealer today after VWoA said they would not help me since i have a 2012 Passat, that the estimated cost is $960.00 to replace the core...

BUT

He also told me VW is back ordered on these parts for 2-3 months so even if i wanted to pay that amount, which i dont, he couldn't help me anyway for a few months, nor can the dealers in Milwaukee (My dealer is in Madison)!

Crazy. I feel i could do this project, but right now its -2 degrees and I do not have a heated garage. So i am checking with my friend to see if he has time to do it (As of this week and next, i cant tackle it), if not there is a great mechanic in Milwaukee i am going to bring it to.

Drove it home last night, had to play with the climate to get it good. Basically was warm, to a bit hot, but the side windows were frosted up (Drivers was kinda ok) and windshield was mostly good.

Frustrating.:(
 

Rico567

Top Post Dawg
Joined
Jun 13, 2003
Location
Central IL
TDI
2013 Passat TDI SEL Premium (Turned in 7/7/18)
<snip>
He also told me VW is back ordered on these parts for 2-3 months so even if i wanted to pay that amount, which i dont, he couldn't help me anyway for a few months, nor can the dealers in Milwaukee (My dealer is in Madison)!
<snip>
It's frustrating to have a car with a sub-optimal heater in winter, that's for sure, and up where you live, double down! But in this, I think that time may be on your side. We were also subject to the nationwide back order. I originally went in before Christmas, but they had no heater cores, and gave me a date of 1/7. We went ahead and drove on a holiday vacation to VA despite the cold passenger footwell, with my wife having a couple of blankets over her legs, and all went well. Got a call when we were back East that they had gotten a core in for me, and I got the car in and had it replaced yesterday. This situation is so widespread, and, as you say, with months-long waits, that I can't help but think that VW is going to extend that 10/120 warranty to more vehicle. Keep hoping!
 

BarryMunson

Well-known member
Joined
Aug 13, 2004
Location
Cleveland Ohio, U.S. of A.
TDI
2014 Passat tdi SEL
2014 Passat tdi heater core replacement.

I tackled this project today. Took about 4 hours start to finish. Thanks to 767Wrench for the how to pictures. Some things I encountered...
Draining the coolant was done by disconnecting the radiator quick disconnectors on the middle and bottom passenger side hoses of the radiator after dropping the belly pan. I was able to drain out about a gallon and a half. Lots of reddish gritty sediment settled at the bottom of the bucket. I did two fill and flushes with 50/50 distilled water and G13 coolant. After the second flush, the coolant appeared clear of any solids. I left the system drained and tackled removing the core.
I loosened the 6mm clamp bolt for the heater tubes passing through the firewall using a nut driver with about 3/4 of the handle sawed off. It's really hard to see the recessed hole that the bolt lives in, but it's directly in between the inlet and outlet tubes. There was just enough room to fit my hand in there and loosen the bolt.
All the panels under the drivers side dash came out exactly as 767Wrench described. My sawed-off 6mm nut driver came in handy here. Now time to disconnect the core lines. You will need a 3mm allen wrench for the clamp screws. You bend them open and they come off away from the tubing. Pulling the lines apart was a bit of a bear. I had to bend the lower tube of the core as I pulled hard away from the lower engine supply tube. I quickly discovered a lot of the resistance was from the tight fit of the O-ring inside the joint. You just have to be patient. I'd say about a cup of coolant drained out once everything was opened up. Have a container or an old towel ready.
The core was very tight pulling out of the heater duct. As you slide in the new core, you have to push the engine supply lines forward to make room for the lines of the new core to pass by. I used a 12 inch piece of 2 inch diameter wooden doweling to do this, which worked well. Push forward with the dowel as you GENTLY pull back on the core tubing to get the tubing connections aligned. Once the tubing was aligned, I used 767Wrench's technique of placing the edge of my dowel against the lip on the core tube, and lightly tapping the dowel with a mallet. This quickly popped the tubing ends together with lip of the core tube flush with the supply tube. The gasket kit comes with new clamps, and they go on just like they came off.
I then filled the radiator with coolant, and took it for a test drive. No leaks and lots of heat once again!


I have tried to reach my arm in from the engine topside to loosen that 6mm screw. I can only get my fingertips on the ratchet and then dropped it. There is only about 3 inches of arm clearance between the engine and firewall.

I then removed the lower plastic engine catch pan and tried to come up from below to reach the 6mm screw. I could not get on the 6mm screw.

Any suggestions here on a 2014 Passat? There's no arm room from above to get to the coolant fittings at the firewall.

I thought I might try and separate the core inside the passenger compartment without loosening the 6mm screw. That does not look promising at this point as I think I might have to cut the core tubes for removal.

Would the be more room to wiggle the old core to the rear if I took out the electric heater grid?

I'm looking for suggestions here. Thanks.
 

dslskier

New member
Joined
Jun 27, 2016
Location
Fishers, IN.
TDI
2015 Passat SEL
accessing firewall screw

I can help with the last question.....after just replacing the heater core on my '15 65K mile TDI SEL.
I also struggled to reach the 6mm firewall screw to enable some play to the connecter pipes to the heater core. I found that if the air intake duct to the turbo housing was removed access was easy. Various vacuum hoses and electrical plugs need to be removed. The intake attaches to the turbo housing with a single easily accessible T30. The intake then rotates past the flanges after removing the front clamp.
The upper hose is then removed by releasing the wire latch on the right with a screwdriver. It then takes quite a bit of force to pull it off. Likewise to replace it with a light hammer.
I turned my '13 TDI SEL back to VW with 103K since the heater core was clogged. I had to replace the adBlue heater on that one and expect to also perform that on the '15 some day.
 

BarryMunson

Well-known member
Joined
Aug 13, 2004
Location
Cleveland Ohio, U.S. of A.
TDI
2014 Passat tdi SEL
I can help with the last question.....after just replacing the heater core on my '15 65K mile TDI SEL.
I also struggled to reach the 6mm firewall screw to enable some play to the connecter pipes to the heater core. I found that if the air intake duct to the turbo housing was removed access was easy. Various vacuum hoses and electrical plugs need to be removed. The intake attaches to the turbo housing with a single easily accessible T30. The intake then rotates past the flanges after removing the front clamp.
The upper hose is then removed by releasing the wire latch on the right with a screwdriver. It then takes quite a bit of force to pull it off. Likewise to replace it with a light hammer.
I turned my '13 TDI SEL back to VW with 103K since the heater core was clogged. I had to replace the adBlue heater on that one and expect to also perform that on the '15 some day.

It's been a little over a year now since I worked on my heater core. I did manage to get on the heater core tubes at the firewall with a cut down nut driver and socket wrench. There was a lot of brownish colored flakes seen that clogged up the very small core tube openings.

The sad part is that it is once again clogging after only one winter driving season. This is after also performing the shop vac cleaning method through the coolant reservoir that was posted here.
 

MostroDiesel

Veteran Member
Joined
Aug 6, 2009
Location
North Haven, CT and Brooklyn, NY
TDI
2012 Passat Gasser VR6; (Sold and missed) 09 JSW DSG Pano Blue Graphite Build Date 05/09
Well hello TDI folks! I see my last visit here was in 2012, back when I had my 09 JSW, before moving to Manhattan and selling it.

I have recently picked up a 2012 Passat (though not a TDI -- don't kill me) and have had a rough day trying to do this heater core procedure.

Basically I chickened out when trying to remove the quick-connect coupler at the firewall. Didn't seem to want to budge, and I didn't want to wreck the heater pipes between the firewall and core.

So, instead, I found another way to wreck them. Since I hadn't loosened the nut at the firewall, I was rassling at the core trying to get the pipes to separate, and mangled the flanges on the pipes. Result? When reassembling, they just didn't want to go back together, and I had leaks at the top. Removing and reattempting didn't improve matters.

So a couple questions: how much force do you need to separate the quick coupler at the firewall? And, if I am left with no alternative but to replace the pipes, does anyone know how this is done? They seem reasonable at $65, not too bad for a newbie mess-up on a new vehicle.

In the end, I expect these moments on an unfamiliar platform, so I'm not too bent out of shape. And I'm glad to be able to tap into this EXTREMLY fine site, even if I'm a gasser interloper!

By the way, the car has 158k, and the coolant was flushed at 75K from the records I have. Today it is a nice, thin, brown, tea-colored horror show, so no surprise about the clogged core. I'm gambling on getting through the winter on the replacement core, then addressing the coolant and other service items at 160K -- doing it myself too. I'll be okay with replacing the core again if I have to then.

Looking forward to hearing your thoughts!
 

suthn3

New member
Joined
May 11, 2016
Location
31602
TDI
2004 Passat GLS
Hello,
I am experiencing the same as in possible clogged heater core, but my reason for messaging you is that I am unable to view a clear picture of your pictures. I sends me to a separate site to view them, so will have to do this for each photo, or do I have to subscribe with this other site inorder to see a clearer picture for each picture at a time.
Thank you,
Jon
 

forrest resto`s

Veteran Member
Joined
Jul 8, 2007
Location
athens ga.
TDI
2000 jetta tdi auto rc2 2013 passat tdi 2015 passat tdi auto 2011 jetta tdi nav. s'roof..man. dpf delete 1970 GTO JUDGE 520 HP
Is your passat a 2004?? I believe this thread would be different as far as replacement procedures..I believe this is for the 2012 -2014 or around that
 

PLC Geek

Well-known member
Joined
Jan 24, 2017
Location
Murrieta, CA
TDI
2015 TDI SE 6MT
I replaced my heater core this weekend. I pulled this fitting off again to gain access to the 6mm bolt that secure the heater tubes to the firewall.
http://forums.tdiclub.com/showthread.php?t=504721


Having a person help is the key here. I don't know how a person do this job alone. I fought the tubes for twenty minutes to try and get them loose before I smarted up enough to go ask for help.



I had my son pull on the tubes from the engine firewall side while I pulled from the heater core side. The tubes popped right off. Then I had him pull again while I slid the new core in place. He pushed and wiggled the tubes while I lined them back up. To seat the flanges over the o-rings I had him push on the tubes with a piece of wood while I used the handle of a wooden shop brush and a mallet to tap against the flange to seat them. With the help it took like 5 minutes to swap the core.
 

NikoSRB

Member
Joined
Sep 11, 2020
Location
Ottawa, Canada
TDI
2013 Passat (NMS) TDI
My 2012 passat unfortunately had the clogged heater core issue. At first I thought it was going to be very costly or labor intensive to fix but after some research it turns out its not a dash out procedure on these cars and is actually relatively easy and cheap to do yourself. I did mine start to finish in about 3 hours.

Heater core PN: 561819031B

Seals and clamps PN: 561898380

Car was at 77,000 miles. Build date 04/12. Climatronic dual climate control. G12 coolant was the factory fill and had only been serviced with G12 until now. The core is clogged with thick white buildup. It may be white rather than the pink that some have reported because I flushed it before removal.

Buildup on the inside of the tank


Buildup inside the tubes. We scraped some of it away before this pic to see what it was.


Discoloration of the lines compared to new


A few pics of the removal. The trim has one torx screw and then drops straight down and out


The storage compartment is removed to access screws for the under dash panel. I just pushed in on the sides to get the tabs past and then it rotates down and comes out. It took some force but I didn't see another way to remove it easily.


The under dash panel has a few screws to remove it. The data link connector needs removed. There are 3 clips on it to depress from the back side. The foot vent can be removed after the panel it has a few torx screws.


This panel covers the heater core. 4 screws remove it


The core exposed. Remove the clamps and pull the lines apart. This was the hardest part. The manual tells you to loosen the 6mm screw that is in between the heater core lines under the hood. It is recessed in a hole between the coolant lines. It must aid in allowing you to move the lines off of the core. It was still tough to do even with it loosened. The bolt is somewhat hard to get to under the hood. I left the lines under the hood hooked up and just drained the coolant at my block heater because it was a lot easier than messing with the lines at the firewall. The pipes leading to the core stay attached and the connection is made where you see the clamps in the pictures. Make sure not to cut the new o rings when trying to reinstall the lines. I bent the lines on the old core to remove it but the new one took more patience as I didn't want to bend it much. The flanges on the pipes kept wanting to cut the o rings as I worked the heater core lines past each other. It would be wise to do a leak check with engine running before reinstalling the trim.

A tip to get the flanges fully seated on the heater core so you can install the clamps. I went under the hood and pushed firmly multiple times on the hose connections to try and seat the pipes onto the core. I also took a rubber mallet and small piece of wood and was able to catch the rib on the line to knock it into place. The lines in the car just don't seem to give a whole lot. Just be very careful not to use too much force when "forcing" things! The lines are just thin aluminum after all!

The core removed. It pulls straight out once the lines are off. I didn't get much coolant out of the lines after I drained the car. This catch can was plenty large enough. Cover the area with rags to catch any other spillage when pulling apart the lines.

Info note: the electric auxiliary heater grid sits directly in front of the heater core and slides out like the core.

Heat works great with the new core. Both sides are HOT on Hi setting and high blower. Decent heat starts being produced with the engine at 145 degrees
I was able to find the core for $74 and the seals for $14 although you could probably reuse the clamps and o rings if you had to. I purchased mine from ecs tuning.
Where is located block heater that you drained coolant?
 

Penst8grad

Active member
Joined
Nov 24, 2017
Location
Pa
TDI
2015 Passat TDI SEL
How the fudge am I supposed to get to the 6mm bolt in the engine compartment?

I have everything apart, except the heater core clamps, and that is the last thing I was going to do before pulling the core. I can't even get my arm back in there to get to the thing. I can see it but I can't touch it.

I'm going to be exceptionally upset if one bolt means the bride taking her car to the dealer. They estimated it at $900!
 

NikoSRB

Member
Joined
Sep 11, 2020
Location
Ottawa, Canada
TDI
2013 Passat (NMS) TDI
How the fudge am I supposed to get to the 6mm bolt in the engine compartment?

I have everything apart, except the heater core clamps, and that is the last thing I was going to do before pulling the core. I can't even get my arm back in there to get to the thing. I can see it but I can't touch it.

I'm going to be exceptionally upset if one bolt means the bride taking her car to the dealer. They estimated it at $900!
I personally didn’t. I just changed it from inside but you need to be patient to remove and putting everything back. It worked for me. Good luck!
 

Penst8grad

Active member
Joined
Nov 24, 2017
Location
Pa
TDI
2015 Passat TDI SEL
I personally didn’t. I just changed it from inside but you need to be patient to remove and putting everything back. It worked for me. Good luck!
I'm very tempted to do that. If I'm understanding correctly, I should be able to shoehorn (gently bend) the new core into place?

The only reason I haven't tried that and break the pipes I' out the $900 for a new core, plus towing, and any other parts that may be wrecked.
 

NikoSRB

Member
Joined
Sep 11, 2020
Location
Ottawa, Canada
TDI
2013 Passat (NMS) TDI
I'm very tempted to do that. If I'm understanding correctly, I should be able to shoehorn (gently bend) the new core into place?

The only reason I haven't tried that and break the pipes I' out the $900 for a new core, plus towing, and any other parts that may be wrecked.
[/QUOTE
Big help for you there is patience. I was able to change that without any damage at all. I was driving car for two days without putting that black plastic cover just to make sure there is no leak. My heat now in the car is fabulous!
 
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