Another heater core?

[klburton22]

I bought my 2014 Passat in August 2019 and the Carfax report said the heater core had been replaced at 35k miles. I thought that was odd but didn't think much about it. Last February I lost all heat and promptly got the car into the dealer. They told me the heater core was plugged and it would be replaced under warranty. Unfortunately the mechanic didn't make sure the hoses were on right and the next day I had coolant dripping on my carpet. Back to the shop it went, the manager told me they had to replace the heater core again because they received a defective one and would clean my carpet as well. Six days later I get my car back, and I have heat through the rest of the winter and spring. I don't use my heater until last week and notice that the passengers side of the windshield is not defrosting. I turn the heater on high and feel the vents on that side, and the air was cold. Now I'm thinking that it's probably something wrong with the vents not working on the passengers side. I take the car to the dealer because it's still under warranty. The shop tells me heater core is plugging up again, but they have a new way of flushing the system that should fix the problem. It's only been seven months since the last heater care replacement. I have 20k miles left on my warranty and if I have to put one more heater core in this car I will be trading it in on a Toyota. This is reticuloses, and bad engineering.

 

[Tom in PT]

It is truly ridiculous. There are many reports of multiple, repeated heater core failures. One theory I have seen is that the combination of high temps during regenerations and the G13 coolant formulation leads to formulation of deposits in the core - plugging eventually. You really have to wonder about the rest of the cooling system getting deposits formed in them and that cannot be good. I once asked the question if changing to G12 ++ coolant instead of G13 would solve the problem but nobody answered . . .

 

[06bluebeetletdi]

Twice here: 12/15 41,000 miles 10/17 53,000 miles with the water pump/timing belt etc 10 days later just rolled 91,000 miles. 2014 sel premium

 

[BKmetz]

On my 2014 Passat SE I had two heater cores replaced under warranty. The third heater core was starting to plug up when I sold the car back to VW in Jan of 2018.

No Problem with the heater core yet on my 2015.

 

[Rochester14]

I bought my 2014 Passat in August 2019 and the Carfax report said the heater core had been replaced at 35k miles. I thought that was odd but didn't think much about it. Last February I lost all heat and promptly got the car into the dealer. They told me the heater core was plugged and it would be replaced under warranty. Unfortunately the mechanic didn't make sure the hoses were on right and the next day I had coolant dripping on my carpet. Back to the shop it went, the manager told me they had to replace the heater core again because they received a defective one and would clean my carpet as well. Six days later I get my car back, and I have heat through the rest of the winter and spring. I don't use my heater until last week and notice that the passengers side of the windshield is not defrosting. I turn the heater on high and feel the vents on that side, and the air was cold. Now I'm thinking that it's probably something wrong with the vents not working on the passengers side. I take the car to the dealer because it's still under warranty. The shop tells me heater core is plugging up again, but they have a new way of flushing the system that should fix the problem. It's only been seven months since the last heater care replacement. I have 20k miles left on my warranty and if I have to put one more heater core in this car I will be trading it in on a Toyota. This is reticuloses, and bad engineering.

I bought my 2014 Passat in August 2019 and the Carfax report said the heater core had been replaced at 35k miles. I thought that was odd but didn't think much about it. Last February I lost all heat and promptly got the car into the dealer. They told me the heater core was plugged and it would be replaced under warranty. Unfortunately the mechanic didn't make sure the hoses were on right and the next day I had coolant dripping on my carpet. Back to the shop it went, the manager told me they had to replace the heater core again because they received a defective one and would clean my carpet as well. Six days later I get my car back, and I have heat through the rest of the winter and spring. I don't use my heater until last week and notice that the passengers side of the windshield is not defrosting. I turn the heater on high and feel the vents on that side, and the air was cold. Now I'm thinking that it's probably something wrong with the vents not working on the passengers side. I take the car to the dealer because it's still under warranty. The shop tells me heater core is plugging up again, but they have a new way of flushing the system that should fix the problem. It's only been seven months since the last heater care replacement. I have 20k miles left on my warranty and if I have to put one more heater core in this car I will be trading it in on a Toyota. This is reticuloses, and bad engineering.

I bought 2014 Passat SEL last July 2020 and the moment I turned 35K miles the right side heater core went out. The VW Dealership said this wasn't normal problem but after reading few complaints from this site, it is a problem. Thank you for sharing.

 

[oilhammer]

Yep, it'll keep doing it, too. You can "fix" it forever, if you want.

 

[251]

No Problem with the heater core yet on my 2015.

Just a matter of time. Heater core on my 2015 clogged up last October at 70k.

 

[pedroYUL]

Just a matter of time. Heater core on my 2015 clogged up last October at 70k.

I get nervous when I read posts like these. No issues here with my 2015, but besides a tune, how can this risk be prevented/eliminated?

Should I flush with water and refill with the least possible antifreeze for my area? VW now only sells premixed 50:50 antifreeze (G13 for all cars) by the gallon (earlier this year when I changed the GSW timing belt), but a lower dilution is always possible.

 

[251]

I get nervous when I read posts like these. No issues here with my 2015, but besides a tune, how can this risk be prevented/eliminated?

Know someone here was changing their coolant annually to prevent heater core from clogging up but it still clogged up. Most of us have to deal with freezing temps in winter so increasing ratio of water to coolant isn't really a solution. You're in Michigan so I know you get the cold - I'm by the Indiana/Michigan line. I'd stick with 50-50 coolant.

A tune should take care of the clogging (or at least minimize the regens/clogging) from what I've read here. I'm just waiting for the extended emissions warranty to run out as it has come in handy for a couple of issues already.

Without a tune best advice is to avoid short trips if possible. Worst thing one can do is turn engine off in mid-regen. Best to have engine get up to normal operating temp and run it on the highway on a regular basis. I have a 70 mile round trip commute and can plan on when a regen occurs as I monitor my soot levels via Polar-FIS. I've found the regens are consistent and predictable with the CVCA which wasn't the case with the 2014 CKRA that I previously owned. I have another vehicle I use for short trips in town so I save my Passat for the commuting and long trips.

Wish these CVCA engines/emissions system were like the ALH cars but they're not. Life is too short to worry about this.

One other thing - if you start losing heat get the heater core changed soon as possible! Mine failed on a road trip. I was able to get to my destination but hardly any heat. Unfortunately it was 600 miles to home - made it a third of the way but due to the clogging the hot coolant got backed up on the inlet side of the radiator (clogging restricts the flow of coolant) which then melted a hole in a plastic fitting! Dealer #1 replaced fitting but did not change the heater core - said it would get me home which was not the case. Only got 175 miles down the road and another melted hole. Dealer #2 did same thing as #1 and again said it'd get me home. OK, 30 miles up the road - same thing again! Dealer #3 changed the fitting and the heater core - finally was able to get home. Yes, first two dealers just replaced the failed part (melted plastic fitting) without figuring out what caused that to happen which was the clogged heater core. So don't delay in replacing a failing heater core otherwise you're bound to have the experience I did.

 

[Trjoel]

Just bought a 2014 Passat TDI SEL in June of this year. Will look out for this now I guess ... thanks for the heads up!

 

[Tom in PT]

VW gave owners a warranty extension for the heater core, the dealer should do the repair. I think it was a 10 year warranty, investigate before you do it yourself if the problem shows up.

 

[mattbevans]

I will say this...... I am starting to think that G13 coolant might not be the most stable coolant out there. I needed to flush the heater core in my Passat after the heater core was replaced 2K miles ago as the techs really did not do a proper flush of the system as they were supposed to. So I went and got some G12++ for the parts store and I was going to use the half 3L of G13 My father in law gave me that he got from his neighbor. The jug looked like it had sat around for a while but I didn't really think much of it. Went to go fill up my coolant in my Passat and when I poured the coolant into a clear container, it had a lot of deposits in it as well. Needless to say I disposed of that stuff and ended up just putting G12++ in my car. My guess is this stuff doesn't have a long shelf life which is why I think there is an uptick in heater cores post fix because these things sat around for two years of more. Its simply my observation and a sample size of one but I do think there is something about the glycerin in G13 that would cause problems especially in a high heat situation.

 

[Lex Tdi]

I will say this...... I am starting to think that G13 coolant might not be the most stable coolant out there. I needed to flush the heater core in my Passat after the heater core was replaced 2K miles ago as the techs really did not do a proper flush of the system as they were supposed to. So I went and got some G12++ for the parts store and I was going to use the half 3L of G13 My father in law gave me that he got from his neighbor. The jug looked like it had sat around for a while but I didn't really think much of it. Went to go fill up my coolant in my Passat and when I poured the coolant into a clear container, it had a lot of deposits in it as well. Needless to say I disposed of that stuff and ended up just putting G12++ in my car. My guess is this stuff doesn't have a long shelf life which is why I think there is an uptick in heater cores post fix because these things sat around for two years of more. Its simply my observation and a sample size of one but I do think there is something about the glycerin in G13 that would cause problems especially in a high heat situation.

I've been wondering it about it because the G12 stuff was indestructible (two very high mileage cars with zero issues) but i dont know enough about all the new systems versus the old alh... anyone with better mechanical insight care to make suggestions? I get that would probably void the warranty but the warranty sucks if the stuff keeps breaking down and causing heater core issues....

 

[Tom in PT]

FWIW, on my '13, the coolant reservoir in the engine bay says "G12" on it so I can't see how using G12 would void the warranty. But, after several years and about 10,000 miles on G13 since my heater core was replaced, the heat works great and the inside of the coolant reservoir is clean so I don't know which is better.

 

[klburton22]

Well it's been two months and I still have heat, hoping to make it through the winter. I have about 15k miles left on my warranty, should hit that around June, after that it will get a delete and tune plus I will be adding an inline coolant filter just before the inlet to the heater core. I'm hoping that will permanently fix the problem.

 

[Williamkevin]

Well I had a new heater core replaced last winter, and today I found the passenger side is cold again. I came here and found this new thread, hoping someone has found out what the true cause is. My unit is a 2015 with 135,000kms about 84,000miles. I run lots of hiway and I have it tuned. I might have put 20,000kms on since the last core replacement. So I don't see any other issues within the coolant system other than the heater core. The orifices in the core must be too small. However how does the car travel only 20k and need another when it previously went 110k. The system must be majorly contaminated to clog up this quickly. I wonder if every brand of coolant is the same with the same results. I will be on the phone in the morning try to speak to a few shops.

 

[IndigoBlueWagon]

I've been wondering it about it because the G12 stuff was indestructible (two very high mileage cars with zero issues) but i dont know enough about all the new systems versus the old alh... anyone with better mechanical insight care to make suggestions? I get that would probably void the warranty but the warranty sucks if the stuff keeps breaking down and causing heater core issues....

The older cars were much easier on coolant and the cooling systems in general. When these cars go into regen the exhaust manifold gets up to 1400+ degrees, sometimes for a half hour or more. And now with more aggressive emissions tuning people believe the coolant is boiling, than then clogging the heater core.

By contrast, you have to beat the snot out of a rotory pump TDI to even get the cooling fans to run. They run way, way cooler than the newer cars.

 

[adjat84th]

Well it's been two months and I still have heat, hoping to make it through the winter. I have about 15k miles left on my warranty, should hit that around June, after that it will get a delete and tune plus I will be adding an inline coolant filter just before the inlet to the heater core. I'm hoping that will permanently fix the problem.

A delete & tune will eliminate the LP EGR which is directly before the heater core in the coolant path. That LP EGR likely scorches the coolant and is what causes heater cores to plug up somewhat frequently...when @oilhammer says you can "fix" it forever, I believe this is what they're referring to in addition to IBW's comment above.
Not sure a filter is needed after ditching the offending components.

 

[Williamkevin]

Interesting update. I spoke to the service manager at my VW dealer here. When they replaced the core last year he had to eat the repair that VW would not cover it. He said being that I did not have an emission code come of from the EGR they would not cover it. Now mine is a 2015 and apparently they are treating them differently from the older versions. kinda brutal for sure. So he is going to look into it tomorrow and let me know the best course of action. I surely don't want to be paying this time especially after only putting on 20k since the last one. I will be calling VW forsure if he tells me I have to pay this time.

 

[mrrhtuner]

Interesting update. I spoke to the service manager at my VW dealer here. When they replaced the core last year he had to eat the repair that VW would not cover it. He said being that I did not have an emission code come of from the EGR they would not cover it. Now mine is a 2015 and apparently they are treating them differently from the older versions. kinda brutal for sure. So he is going to look into it tomorrow and let me know the best course of action. I surely don't want to be paying this time especially after only putting on 20k since the last one. I will be calling VW forsure if he tells me I have to pay this time.

Well **** that.

I was considering this turd of NMS Passat. No more. Not going to deal with heater core **** like this.

 

[adjat84th]

FWIW, heater cores are actually really easy to replace on these.

 

[klburton22]

FWIW, heater cores are actually really easy to replace on these.

I watched a youtube video on the replacement and yes it is very easy.

 

[Williamkevin]

I am going to flush the system on mine really well and see if that makes a difference. The problem is that the core traps the particulates instead of letting them flow through. I stopped at a local VW/Audi service shop and he had two of the cores that he cut in half and it was amazing the amount it was plugged up. This guy told me to just flush the system really well every 2 years or so and I shouldn't have a problem. I love this car too much to let a heater core stop me.....

 

[pedroYUL]

I also watched the video, and priced the part...not bad at all.
In the video I watched that earlier Passat had a slot, similar to a Canadian Jetta Mk5 I used to have. In that slot there was an electric heater that failed, and it costed me more to change that part with a used one, than a new heater core of these, if I ever need one.

Looks like the way to solve a quick cabin heat was to use a potent, yet small heater core and no electric supplementary one, yet the slot for one is there. I wonder if that is part of the cold weather package for Canada?

That mk5 was so quick to heat the cabin, it was unreal. It also killed a battery in like 4 years.

 

[50harleyrider]

I have a 2015 with 60k and am concerned. What should we do to prevent this from happening? a 2 year flush interval and G12 coolant? Or just wait and fix if it happens? I put an all aluminum core in My b5.5 and had to remove the dash.

 

[pedroYUL]

I have a 2015 with 60k and am concerned. What should we do to prevent this from happening? a 2 year flush interval and G12 coolant? Or just wait and fix if it happens? I put an all aluminum core in My b5.5 and had to remove the dash.

Find a video, this one is super easy, and the part is like $25.
My 2015 has 80-something thousand miles, and I don't believe it has plugged a core. Part 2 of the fix was done recently, after I bought the car last year, so we'll see.

 

[Williamkevin]

I have a 2015 with 60k and am concerned. What should we do to prevent this from happening? a 2 year flush interval and G12 coolant? Or just wait and fix if it happens? I put an all aluminum core in My b5.5 and had to remove the dash.

I would just get it flushed and put the G13 back in. for the $200 or so to flush I think it should be good for a while especially after the original stuff is gone. the service shop I was talking to said that once they flushed and got rid of the original fluid the second cores were lasting. So I am getting mine done.

 

[silvrmax04]

Just replaced mine this week. Parts were $60 from dealer. Heater core and oring kit. Watched a Utube video. Hardest part was getting the pipes together at the heater core. 70k on my 2015. Same heater core part number but not under warranty. Makes no sense.

 

[busman1978]

I watched a youtube video on the replacement and yes it is very easy.

Easy(er) than a Mk4 yes, but not easy. I would consider a heater core on a bullnose Ford truck easy. A heater core on a NMS Passat is especially frustrating when it leaks after installation, and you have to start all over again. Especially when you have been without heat for over a year, the shop you have been going to forever is ignoring your calls, and it is the 3rd core going into this 5-yo POS car.

 

[Zambee500]

Just bought a 2014 Passat TDI SEL in June of this year. Will look out for this now I guess ... thanks for the heads up!

To echo Trjoel, I am in the same boat having just bought a 2014 yesterday that I am taking delivery of on Monday. Yikes! After spending the past dozen+ years in the B5.5 forum, I've been perusing the NMS forums to see what I need to be aware of. Lots to learn, it seems. Thanks for the heads-up on the heater core issue, and also the extended warranty!

Also great to see some of the B5.5 family has migrated over the NMS/B7 forums.