Welp, it's official, heater core is DONE-Fer!

Vwkaferman

Veteran Member
Joined
Jun 26, 2021
Location
Mesa, AZ
TDI
2003 Jetta Wagon
Shucks. I'm pretty sure it's had a pinhole leak for quite some time. Windshield fogs up initially when put in defrost, eventually clears up. Today rolling around taking logs, pulled back into driveway and smelled coolant. Hmm, I wonder if that's what the puddle was in my garage when I was messing with the laptop/VCDS. Yep, sure is. Looks as if it's draining out the drain hole, not so much the cabin which is good, I guess.

So, since I'm in AZ I guess I'll be doing the loser thing and bypassing it for now. I've read the horror stories about how hard it is to replace. Daily driver. We make decent money, I wonder if any VW shops in Phoenix area would do it haha. I'm somewhat serious.

Okey dokey, that's it. Other than that, still love driving it.

James
 

csstevej

Top Post Dawg
Joined
Aug 12, 2004
Location
north nj
TDI
2001 golf tdi 4 door auto now a manual, mine, 2000 golf 2 door M/T son's,daughters 98 NB non-TDI 2.0, 2003 TDI NB for next daughter, head repaired and on road,gluten for punishment got another tdi 2001NB,another yellow tdi NB
It’s really not that bad.
Hardest part is trying not to break the plastic pieces.
Last one took me 11 hrs in my neighbors barn during a sleet storm.
That will be the third one I’ve done.
You can always bypass the heater core since your in AZ.
 

gforce1108

Top Post Dawg
Joined
Aug 2, 2006
Location
Newburgh, NY
TDI
04 Jetta GLS BEW, 14 Audi A7 V6 TDI, 13 Porsche Cayenne V6 TDI
Not hard - just time consuming. No head gasket issues? Doing it without breaking into the AC system was a bit tricky - much easier if you discharge the system.
 

Vwkaferman

Veteran Member
Joined
Jun 26, 2021
Location
Mesa, AZ
TDI
2003 Jetta Wagon
Don’t think I have head gasket issues, coolant looks good, no oil, oil cap looks good, no frothing.

Hit up the ole O’Reilly’s. This kit worked perfect. O’Reilly part # 626-001, (Heater Core Bypass Kit). Also, so glad I bought that hose clamp removal tool, best tool I’ve bought in a long time!

This week will be chilly, warming up soon here in AZ so I’ll survive.

 

jayb79

Top Post Dawg
Joined
May 20, 2000
Location
Exeter,NH
You could just pull the o-ring from your coolant cap and have heat. Been driving mine without that o-ring for almost 10 years now.
 

Nuje

Top Post Dawg
Joined
Feb 11, 2005
Location
Island near Vancouver
TDI
2015 Sportwagen; Golf GLS 2002 (swap from 2L gas); 2016 A3 e-tron
You could just pull the o-ring from your coolant cap and have heat. Been driving mine without that o-ring for almost 10 years now.
Can you explain that a little further? Can't figure how removing the o-ring from something in the engine bay gets you heat in the cabin (?).
 

jayb79

Top Post Dawg
Joined
May 20, 2000
Location
Exeter,NH
Taking the oring out of the coolant cap keeps the system from building pressure, not more leak from the heater core. That's assuming it's only leaking after it heats up.
 

Vwkaferman

Veteran Member
Joined
Jun 26, 2021
Location
Mesa, AZ
TDI
2003 Jetta Wagon
Isn’t the system dependent upon being pressurized to properly cool? Same concept with home canning, pressurization raises the boiling point, no?

Living in AZ I’ll stick with the cooling system running optimal if that’s the case. Do appreciate the out of the box thinking though!

James
 

jayb79

Top Post Dawg
Joined
May 20, 2000
Location
Exeter,NH
Yes, it is but diesel efficiency makes it easy to keep it cool. This is assuming all stock and no heavy loads. It's kept me from having to change my heater core but you do have to be careful. I use a scan gauge to keep an eye on actual coolant temps.
 

DuraBioPwr

Veteran Member
Joined
Jan 28, 2020
Location
Eastern Washington
TDI
2004 BEW Jetta (5spd)
The pressure in the system keeps from localized boiling/cavitation in the cylinder head at the hot spots. Water boils at a higher temp at a higher pressure. Once localized boiling occurs then hot spots can form as the boiling water does not move the heat as well as liquid pressurized coolant. Then cracks can form.

Also there is a pressure differential in the water pump that can cause more boiling and localized cavitation wear and actually eat metal. Duramax's have a bit of problem with this even when the pressure system is fine the water pump housing can be pitted and eroded.

Pretty risky business running with no pressure.
 
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