Another heater core?

[thundershorts]

My 2015 passat came with g12 now 61000 miles, no trouble. build date was may 2015. Does anyone know if they installed different heater cores in later production cars and when they started using g13 in the passat. My golf, built same month, is a g13 car. Any test data as to thermal chemical breakdown comparing g12++ vs g13?

 

[IndigoBlueWagon]

G13 has been around for quite a while. I suspect what's different about your Passat is the engine. The EA288 in your car seems less prone after the fix to boiling coolant, which some believe is the cause of heater core clogging on the '12-14 cars. If I owned a '12-14 I'd get it "un" fixed to prevent coolant boiling during regens.

 

[L30NDR3Z]

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've had my 2014 NMS Passat TDI since October 2019 @ 63,000 miles. Over the course of the year and into the next the car was running without issues. I had to get the heater core replaced around November 2020. Where they mentioned the flux of the heater core and the coolant causing the clogging issue and it was under warranty. Now around Feb 14 the heater was clogged again and I took it the dealer and they referred to a direct VW Tech support. They told me that they would replace a majority of the Coolant system and the parts would be ordered and installed at no cost to me. Later they have the parts but the VW Tech told them that the heater core was not the issue but rather engine sediment that was going being moved from the engine to the radiator to the heater core. Im not familiar with the coolant systems of the TDI very well but this sounded off to me. I asked him wether this was common thing for the engine to do even when the maintenance was being done properly on the car. Which to he was a bit hesitant to say anything then said yes its normal. To which I replied then how is this my problem and not VW problem given that since the original core was clogged it could be that it was depositing sediment into the engine before it was replaced and now the whole coolant system was was contaminated. Now im not sure if in the right with this statement but im not going to foot the bill that has probable causes from the original heater core. Otherwise im just going to keep getting the heater core replaced until the warranty runs out then trade it in.
He said he would speak to the rep and call me back with more info.

 

[thundershorts]

There may be something about g13. My passat was built in may 2015 and came with g12. No hint of problem at 65k. My golf was built also in may but came with g13. I've topped off both with g12++. It may be the egr cooler breaks down g13 quicker than g12. g13 supposedly is "greener"----thanks alot.

 

[L30NDR3Z]

I've had my 2014 NMS Passat TDI since October 2019 @ 63,000 miles. Over the course of the year and into the next the car was running without issues. I had to get the heater core replaced around November 2020. Where they mentioned the flux of the heater core and the coolant causing the clogging issue and it was under warranty. Now around Feb 14 the heater was clogged again and I took it the dealer and they referred to a direct VW Tech support. They told me that they would replace a majority of the Coolant system and the parts would be ordered and installed at no cost to me. Later they have the parts but the VW Tech told them that the heater core was not the issue but rather engine sediment that was going being moved from the engine to the radiator to the heater core. Im not familiar with the coolant systems of the TDI very well but this sounded off to me. I asked him wether this was common thing for the engine to do even when the maintenance was being done properly on the car. Which to he was a bit hesitant to say anything then said yes its normal. To which I replied then how is this my problem and not VW problem given that since the original core was clogged it could be that it was depositing sediment into the engine before it was replaced and now the whole coolant system was was contaminated. Now im not sure if in the right with this statement but im not going to foot the bill that has probable causes from the original heater core. Otherwise im just going to keep getting the heater core replaced until the warranty runs out then trade it in.
He said he would speak to the rep and call me back with more info.

Update Feb 26, 2021:

Got a call back from the dealership they just replaced the heater core and flushed the system the best they could. He stated that VW would not replace the heater core after this since the issue was the engine sediment/deposits were causing the clogging. Im about to pick it up today and question wether the original heater core is caused this issue in the first place. Anyone with the knowledge of wether engine deposits/sediments can cause this type of problem?

 

[Tom in PT]

You have to ask the question-what is causing the engine deposits/sediments in the first place? Based on previously published TSB and recall letters, if I remember right it has to do with the coolant becoming acidic over time and excess flux in the heater core coming lose and clogging it. The high temp regenerations may have something to do with that too, accelerating the acidification and degradation of the coolant. If the heater core is clogged, yes there will be sediments present elsewhere which is why it is important to thoroughly flush out the cooling systems when the heater core is replaced. The root cause is a bad cooling system design and a coolant not up to the rigors of this engine. They should replace the heater core as necessary throughout the entire extended warranty period. If they don't, find a different dealer or deal directly with VW.

 

[IndigoBlueWagon]

Initially people were told that the cores on NMS Passats were failing because of flux in the core clogging it. It was described as a manufacturing problem. It appears that the flux issue is (mostly) corrected, but the cores are clogging because of boiling/breakdown of the coolant during the more extensive regens required by the fix.

 

[L30NDR3Z]

You have to ask the question-what is causing the engine deposits/sediments in the first place? Based on previously published TSB and recall letters, if I remember right it has to do with the coolant becoming acidic over time and excess flux in the heater core coming lose and clogging it. The high temp regenerations may have something to do with that too, accelerating the acidification and degradation of the coolant. If the heater core is clogged, yes there will be sediments present elsewhere which is why it is important to thoroughly flush out the cooling systems when the heater core is replaced. The root cause is a bad cooling system design and a coolant not up to the rigors of this engine. They should replace the heater core as necessary throughout the entire extended warranty period. If they don't, find a different dealer or deal directly with VW.

I mentioned this to the dealer in which they reverted back and placed the blame on the previous owners maintenance. So they're BS'ing me. I'll look into other dealers when the problem arises as well. But this Monday I'll call VW to resolve why dealer reverted back to the full replacement of parts and the contradiction of their diagnostics.

 

[L30NDR3Z]

Initially people were told that the cores on NMS Passats were failing because of flux in the core clogging it. It was described as a manufacturing problem. It appears that the flux issue is (mostly) corrected, but the cores are clogging because of boiling/breakdown of the coolant during the more extensive regens required by the fix.

Would this be applicable to start another TSB or recall for the Coolant system or what can be done on my side to prevent this?

 

[IndigoBlueWagon]

If you price them you'll notice heater cores for these cars have gotten really, really cheap from the dealer. https://www.idparts.com/heater-core-oem-nms-passat-561819031c-561819031b-p-6279.html Mechanic I know thinks they may be doing this to avoid a reacall.

A tune would dramatically reduce risks of it clogging. But it could also jeopardize your emissions warranty. Pick your poison.

 

[pedroYUL]

Man, I am tempted to just buy one with clamps and o-rings, and have it just waiting, but my car shows no sign of clogged core at all.

How come this doesn't seem to affect CRUA engine Golf Sportwagens, different heater core?

 

[IndigoBlueWagon]

Different tuning is one possible explanation. Coolant may be less stressed. The CKRA was the most difficult engine for VW to get to an acceptable pollution level for the courts. That's why they gave up on the manual transmission ones.

 

[L30NDR3Z]

If you price them you'll notice heater cores for these cars have gotten really, really cheap from the dealer. https://www.idparts.com/heater-core-oem-nms-passat-561819031c-561819031b-p-6279.html Mechanic I know thinks they may be doing this to avoid a reacall.

A tune would dramatically reduce risks of it clogging. But it could also jeopardize your emissions warranty. Pick your poison.

wow dirt cheap heater core and yeah would help them avoid the recall

Such as a flash tune from Kerma TDI? Would they be looking for ECU flash count if they’re to work on any emissions warranty related problem?

 

[IndigoBlueWagon]

Such as a flash tune from Kerma TDI? Would they be looking for ECU flash count if they’re to work on any emissions warranty related problem?

Exactly.

 

[turbodiesellover]

I stopped having sediment present after delete. The G-13 coolant isn’t up to the task with the regen heat.
I filter my coolant, so I know this to be true. Heater Core Replaced 11-19 with 28,000 miles, dpf intact.
Lots of debris still found after Heater Core replaced, then really slowed and stoped after delete.
I watch my Coolant PH like a hawk, and the PH much more stable after delete too.

 

[turbodig]

Just had the second core done in my 2014 NMS TDI @70k. Was done under the extended core warranty, no questions asked.

I grilled the service writer about it, and she said they've had pretty good luck with the rev B core, and a flush process that goes over and above the regular TSB process. They still get a comeback once in a while, but few and far between.

Makes you wonder if a swap to non-G13 'international' coolant would be worthwhile. I'll probably give that a go once I pass the 120k.

 

[L30NDR3Z]

I stopped having sediment present after delete. The G-13 coolant isn’t up to the task with the regen heat.
I filter my coolant, so I know this to be true. Heater Core Replaced 11-19 with 28,000 miles, dpf intact.
Lots of debris still found after Heater Core replaced, then really slowed and stoped after delete.
I watch my Coolant PH like a hawk, and the PH much more stable after delete too.

At what mileage did you do your delete? Ive been wanting to do the same thing but im waiting to hit the 120k mark. How would I also pass emission after the delete?

 

[L30NDR3Z]

Just had the second core done in my 2014 NMS TDI @70k. Was done under the extended core warranty, no questions asked.

I grilled the service writer about it, and she said they've had pretty good luck with the rev B core, and a flush process that goes over and above the regular TSB process. They still get a comeback once in a while, but few and far between.

Makes you wonder if a swap to non-G13 'international' coolant would be worthwhile. I'll probably give that a go once I pass the 120k.

I actually brought that up to VW customer service they avoided all the coolant questions and heater core issues but they would contact the dealer that serviced my car. They also are having a regional manager contact me later this week. Hopefully they replace all the part they mentioned and I can speak to him about the coolant being the issue to this ordeal

 

[turbodiesellover]

At what mileage did you do your delete? Ive been wanting to do the same thing but im waiting to hit the 120k mark. How would I also pass emission after the delete?

30,000 miles. I deleted my CPO warranty too. I waited 6 months to “shake” everything down that the bumper to bumper warranty would cover.
You won’t pass an emissions test if they test tailpipe emissions.
If they just check to see if the “readiness monitor” is OK and ready, then you can pass with a tuner who sets the monitor to “OK/Ready” (With NO tailpipe test).

 

[ret1614]

I stopped having sediment present after delete. The G-13 coolant isn’t up to the task with the regen heat.
I filter my coolant, so I know this to be true. Heater Core Replaced 11-19 with 28,000 miles, dpf intact.
Lots of debris still found after Heater Core replaced, then really slowed and stoped after delete.
I watch my Coolant PH like a hawk, and the PH much more stable after delete too.

Hey, where did you install your filter? I was looking hard at the degas line to the top of the bottle for simplicity’s sake. But, I’m thinking a better option would be the downstream end of the EGR cooler.

My 2¢ on the coolant issue, as soon as I hit the end of the dieselgate warranty, this car is getting the 6.7L Ford coolant. I’ve had fun with plenty of other coolant types at work (but but but this one is cheaper- Parts and Materials “Manager”) and never had an issue with VC-3-B that I run in my personal truck... 300k on that thing.

 

[Tom in PT]

I like that idea - use the Ford 6.7 coolant. Probably a good idea to do a real thorough flush to avoid mixing the two.

 

[ret1614]

I like that idea - use the Ford 6.7 coolant. Probably a good idea to do a real thorough flush to avoid mixing the two.

Definitely a good idea, they’re different bases.

 

[spepin]

Well, add me to the heater core crowd. Picked up my '14 with 28,000 on it in January of 2020. Right around 55,300 my CEL came on while driving home from work (no chime, or drivability issues). Checked the codes and found P2457. Cleared it to see if it would come back, and it did the next morning on my way to work, and also noticed cold air from the vents (was perfectly fine the previous morning though, so it just came on very quickly). Dropped it at the dealer yesterday along with a short list of CPO warranty issues (none justified a trip to the dealer on their own, so just waited until I had to take it in for something -- plus this way there would be only a single $50 deductible for the CPO warranty related stuff).

 

[turbodiesellover]

Hey, where did you install your filter? I was looking hard at the degas line to the top of the bottle for simplicity’s sake. But, I’m thinking a better option would be the downstream end of the EGR cooler.

My 2¢ on the coolant issue, as soon as I hit the end of the dieselgate warranty, this car is getting the 6.7L Ford coolant. I’ve had fun with plenty of other coolant types at work (but but but this one is cheaper- Parts and Materials “Manager”) and never had an issue with VC-3-B that I run in my personal truck... 300k on that thing.

Yes, I put the inline filter before the degas/coolant bottle. My EGR cooler is still intact, but I have no exhaust running thru it. I used a block-off plate on the EGR Cooler exhaust side. Was too big of a pain to remove the EGR cooler, so I let it ride...

 

[turbodiesellover]

Well, add me to the heater core crowd. Picked up my '14 with 28,000 on it in January of 2020. Right around 55,300 my CEL came on while driving home from work (no chime, or drivability issues). Checked the codes and found P2457. Cleared it to see if it would come back, and it did the next morning on my way to work, and also noticed cold air from the vents (was perfectly fine the previous morning though, so it just came on very quickly). Dropped it at the dealer yesterday along with a short list of CPO warranty issues (none justified a trip to the dealer on their own, so just waited until I had to take it in for something -- plus this way there would be only a single $50 deductible for the CPO warranty related stuff).

Should be. $0 deductible on the Heater Core If you took it in for this issue only.

 

[spepin]

Should be. $0 deductible on the Heater Core If you took it in for this issue only.

Correct -- heater core is a $0 deductible, but asking them to check out the other stuff that's covered under the CPO warranty while it's there, hence the $50 deductible for everything else.

 

[ret1614]

Yes, I put the inline filter before the degas/coolant bottle. My EGR cooler is still intact, but I have no exhaust running thru it. I used a block-off plate on the EGR Cooler exhaust side. Was too big of a pain to remove the EGR cooler, so I let it ride...

That’s starting to look like the plan for me when the warranty ends. Probably going to be about $2k in exhaust and tunes, but I think it’s gonna be worth it.

 

[turbodiesellover]

That’s starting to look like the plan for me when the warranty ends. Probably going to be about $2k in exhaust and tunes, but I think it’s gonna be worth it.

Mine was about $1,800 for everything. Exhaust, Engine Tune and DSG Tune.

 

[spepin]

I'm not sure if it's just my imagination, but it seems that following the heater core replacement, my car regens more frequently. My daily commute is 120 miles (60 each way), so I don't take short trips around town. Following the core replacement, it seems that my car is regenerating every time I get home (fan is running on shutdown). I have a Polar FIS on order (should arrive tomorrow) so I can keep a closer eye on DPF conditions, but I'm just curious if this is related to the heater core replacement, or just simply due to warmer temperatures (and running A/C).

 

[IndigoBlueWagon]

The may have updated the ECU while the car was getting the core.