'14 Jetta TDI--heater core issue? heat only to driver side--battery drain too

ncbound44

Well-known member
Joined
Sep 5, 2012
Location
New York
TDI
1991 VW diesel, 2002 Jetta TDI
Its that time of year when I have just started to need to defog my windshield. I purchased a '14 Jetta TDI in July 2021 with just under 90k on it, after retiring my '02 with 354K on it (I am still sad about this, but a girl only has so many hours in a week to work on her car). I noticed the radiator fan running fast (start up to shut off--but not after shut off) as well as the driver side only defogging in the morning. I had to run the heat on my way to work Friday morning and only had heat on the farthest left vent, decreasing as you move to the passenger side. From my research, I see that a common failure in the Passat TDIs of this year is a heater core failure with symptoms similar to mine (I have not been able to confirm that the radiator fan speed is high in these forums). The Passat has a TSB for the heater core--but I cannot find one for the Jetta. Has anyone had this problem with their jetta? Is there a tsb for Jettas? just looking for any insight or help.. thanks!

Update: I appear to have a draining battery as well.. seem to have started at about the same time--noticed a slow start 2 weeks ago when i also noticed no heat... attributed the start time to the heat but have since had a dead battery and longer start time after sitting.
 
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DivineChaos

Top Post Dawg
Joined
Jul 27, 2019
Location
Minnesota
TDI
mk6 jetta sportwagen tdi
I believe I read somewhere that they covered a lot of these under the emissions warranty because it caused the heater cores to plug up more frequently. Yes it is a problem in these ones. You might have to look up if it's covered under warranty.
 

pebjr

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Joined
Sep 8, 2013
Location
Eastern North Carolina
TDI
2009 Jetta; 2015 Golf S
I had an 09 Jetta that had a heater core plug and it was replaced under the extended emission warranty. I did have a CEL, but don't remember the code. AS I recall, the emission warranty will only cover it if there is a CEL.
 

TurboABA

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Joined
Jul 24, 2010
Location
Kitchener, ON
TDI
RIP-2010 Jetta 6spd 2014 Touareg Execline
Heater cores had a separate recall on the CRs..... get a dealer to run your VIN....
 

ncbound44

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Joined
Sep 5, 2012
Location
New York
TDI
1991 VW diesel, 2002 Jetta TDI
no recalls on my VIN...called VW of America--my car is not under warranty.

I now ALSO have a parasitic battery drain... the longer it sits the harder to start... after only 2 mile commutes once ever 12 hours for 3 days it didn't start leaving work---got a jump and drove for 45 min--got battery etc tested at auto zone and was told they are fine...
after a 16 hour sit it took a good 3+ seconds to start.

I am curious if my heat issue could be related (last week when I noticed the heat issue I also noticed a slightly longer start time after a 36 hour sit)
 

TurboABA

Top Post Dawg
Joined
Jul 24, 2010
Location
Kitchener, ON
TDI
RIP-2010 Jetta 6spd 2014 Touareg Execline
Look at the date on your battery. If it's original, it's time to replace it..... some people will get 7 years out of an OEM unit, but most will only get 5, and that's more realistic.
If you know how to use a multimeter, you can diagnose for parasitic drain if you really think that's the issue.
 

ncbound44

Well-known member
Joined
Sep 5, 2012
Location
New York
TDI
1991 VW diesel, 2002 Jetta TDI
Look at the date on your battery. If it's original, it's time to replace it..... some people will get 7 years out of an OEM unit, but most will only get 5, and that's more realistic.
If you know how to use a multimeter, you can diagnose for parasitic drain if you really think that's the issue.
Auto one’s test cleared battery, alternator, and starter… although I’ve been told there testing isn’t always accurate . I’m trying to find the date on the battery but failing
 

TurboABA

Top Post Dawg
Joined
Jul 24, 2010
Location
Kitchener, ON
TDI
RIP-2010 Jetta 6spd 2014 Touareg Execline
What brand is it? What information can you see on it? Does it have a VAG part number on it? Something like 5K0 915 105 G
Does it have sight window\bubble?
 

TurboABA

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Joined
Jul 24, 2010
Location
Kitchener, ON
TDI
RIP-2010 Jetta 6spd 2014 Touareg Execline
That's an original battery. I'd totally replace it even if it "tested" ok. (especially because your own experience confirms that it has died on you)
The siteglass says that the fill level is OK.
You're right at the limit of how long the OEM battery lasts as per my previous statement, and TDIs don't like to start if they spin too slow when cranking. With a fresh battery, you can at least eliminate one suspect component from the equation.
 

ncbound44

Well-known member
Joined
Sep 5, 2012
Location
New York
TDI
1991 VW diesel, 2002 Jetta TDI
That's an original battery. I'd totally replace it even if it "tested" ok. (especially because your own experience confirms that it has died on you)
The siteglass says that the fill level is OK.
You're right at the limit of how long the OEM battery lasts as per my previous statement, and TDIs don't like to start if they spin too slow when cranking. With a fresh battery, you can at least eliminate one suspect component from the equation.
Thank you so much! I have a euro car place flush my heater core and i have better heat. They tested the battery and say that that is indeed the power problem. I’ve disconnected my negative terminal daily—will changing the battery be an issue? I have autozone telling me they can’t do it because they need the scan tool…
 

TurboABA

Top Post Dawg
Joined
Jul 24, 2010
Location
Kitchener, ON
TDI
RIP-2010 Jetta 6spd 2014 Touareg Execline
I'm not sure your Jetta has BEM coding requirement on it. On my '10 I was able to change the battery just like on dumb vehicles. I'd change it without the scan tool as per autoclowns who already claimed the battery was good.
 

ncbound44

Well-known member
Joined
Sep 5, 2012
Location
New York
TDI
1991 VW diesel, 2002 Jetta TDI
I'm not sure your Jetta has BEM coding requirement on it. On my '10 I was able to change the battery just like on dumb vehicles. I'd change it without the scan tool as per autoclowns who already claimed the battery was good.
Autozone says it needs coding and I’ve found some conflicting threads… seems to be that if i move to an AGM battery i need coding but with a flooded i wouldn’t… still more to read up on… thanks!
 

TurboABA

Top Post Dawg
Joined
Jul 24, 2010
Location
Kitchener, ON
TDI
RIP-2010 Jetta 6spd 2014 Touareg Execline
I'm 99% sure that you don't have BEM and thus no coding is required regardless of what battery you put in, or what Autozone tells you.
Perhaps someone with a '14 can confirm this is you don't believe me.
 

TurboABA

Top Post Dawg
Joined
Jul 24, 2010
Location
Kitchener, ON
TDI
RIP-2010 Jetta 6spd 2014 Touareg Execline
OP, when you replace the battery, you will most likely get a xmas tree of warning lights on your cluster. Some of the newer vehicles require you to drive a little, going straight at something like 15-20mph so that the steering sensor and some others can register\reset. Once all that happens, the idiot lights go away and your car is happy again.
 
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