Not much heat

ejm4

Member
Joined
Apr 27, 2020
Location
PA
TDI
2014 Passat TDI
2014 Passat w/ 26k miles, first chilly morning today in Central PA (41 degrees) and the car got up to 190 degrees, but I had very little warmth coming from the driver side vents and nothing from the passenger side. I tried changing the air flow designations, but it did not change anything. Could this be the famous heater core issue?
 

mattbevans

Member
Joined
Jun 1, 2020
Location
Murfreesboro, TN
TDI
2013 Passat TDI SE
Sounds about right. You might even throw an EGR CEL soon too because of it. All covered under emissions warranty with a loaner provided. Newer cores should be ok as the originals had too much flux from manufacturing. They are also supposed to flush the system twice so make sure they do that. Look up TSB 80-16-01.
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
Joined
Aug 16, 2004
Location
South of Boston
TDI
'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
Unfortunately it appears that the engine in your car, when the dieselgate fix is applied, can boil coolant during regen and plug the heater core. That may be the problem now, and it may happen again. Since you have the warranty and the heater core replacement on your car isn't a huge deal, that may be OK. If it were my car I'd get it tuned to take that risk away, but then you may void the emissions warranty if the dealer discovers the tune. Damned if you do...
 

ejm4

Member
Joined
Apr 27, 2020
Location
PA
TDI
2014 Passat TDI
Sounds about right. You might even throw an EGR CEL soon too because of it. All covered under emissions warranty with a loaner provided. Newer cores should be ok as the originals had too much flux from manufacturing. They are also supposed to flush the system twice so make sure they do that. Look up TSB 80-16-01.
Thanks - dealer appointment scheduled for next week.
 

mattbevans

Member
Joined
Jun 1, 2020
Location
Murfreesboro, TN
TDI
2013 Passat TDI SE
Unfortunately it appears that the engine in your car, when the dieselgate fix is applied, can boil coolant during regen and plug the heater core. That may be the problem now, and it may happen again. Since you have the warranty and the heater core replacement on your car isn't a huge deal, that may be OK. If it were my car I'd get it tuned to take that risk away, but then you may void the emissions warranty if the dealer discovers the tune. Damned if you do...
Has this been documented or is this just speculation? Not sure this makes a ton of sense. Mine plugged at around 50K and had the fix done at 49K and this issue has been going on before the fix. Not trying to be confrontational just curious.
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
Joined
Aug 16, 2004
Location
South of Boston
TDI
'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
Not documented. NMS Passats have had a lot of heater core issues, both before and after the fix. Some say the original issues were because of poor manufacture of the cores, but the issues have persisted. We have customers who report 2 and 3 core replacements. The CKRA engine was difficult to fix, it took multiple attempts for VW to get a fix that the court would accept, and they never were able to provide a satisfactory fix for the manual transmission Passats (not including the '15s, which have a different engine). Mechanics have seen evidence of boiled coolant in a number of cars, and believe it can plug the heater core.
 

mattbevans

Member
Joined
Jun 1, 2020
Location
Murfreesboro, TN
TDI
2013 Passat TDI SE
It is certainly a plausible explanation when you look at the coolant circuit but this generally applies to all the 2.0 TDIs. Have there been issues with the other fixed models? I know the engines are a bit different but looks like the principal is the same. It seems like some of these issues could be the cars having sat around for a few years and not being run caused some of these issues especially when you have excess flux causing the coolant to become acidic. I'm definitely going to keep my eye one this issue.
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
Joined
Aug 16, 2004
Location
South of Boston
TDI
'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
Engines are apparently enough different. The CKRA has a smaller turbo, fuels at different pressures, and is also moving a heavier car. For whatever reasons it allegedly causes higher coolant temperatures. It also has a different thermostat, and many people here have reported Passats running significantly hotter than other CR TDIs.
 

06bluebeetletdi

Veteran Member
Joined
Sep 30, 2012
Location
Middlesex, NC
TDI
'14 Passat TDI SEL and '13 Beetle TDI
My passat has had the heater core replaced twice, at 41,000 miles in December 2015 and at 53,000 miles in October 2017, fix was done at 50,000 miles in September 2017 (it sat most of the 18 months 3/16-9/17). As far as coolant temps, my 14 passat is normally 211-215, sometimes as high as 221 (upper 90s air temperature + regeneration), my 13 beetle is usually 186/190, max 197.
 

06bluebeetletdi

Veteran Member
Joined
Sep 30, 2012
Location
Middlesex, NC
TDI
'14 Passat TDI SEL and '13 Beetle TDI
Coolant temperature of my passat is close to the oil temperature of the beetle, I can’t imagine how hot the passat oil temperature must be (good thing it doesn’t have an oil temperature sensor).
 

TDI-EMS

New member
Joined
Aug 6, 2019
Location
minnesota
TDI
2014 passat tdi dsg
for what it is worth, i had my heater core replaced under emissions warranty. To date it completely fixed my heat problems. it was done about a year ago and i have had 18K miles since. currently at 98000 miles on my '14 passat se
 
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