Coolant Leak (With Photos)

Mike_04GolfTDI

Top Post Dawg
Joined
Nov 19, 2003
Location
Richmond, BC, Canada
TDI
Mine: 2019 Golf R DSG, Wife's: 2015 Golf Comfortline TDI
2015 Golf TDI coolant reservoir was a bit low. Poked around under the hood and found a leaking hose.

Normally that wouldn't be a big deal, but both ends of the hose are leaking. To me that suggests a possible problem with the hose material itself, rather than a simple leak.

The hose appears to be installed as far as it goes on the hose barbs, and the clamps are in place and appear to be positioned properly. Again, this suggests the hose material itself rather than an installation issue.

We'll probably just get this fixed under warranty.

Anyway, here are the photos. (The area we're looking at is to the left of the brake booster if you're facing the firewall)

This end is closer to the firewall
http://pics.tdiclub.com/showfull.php?photo=117810

This is the other end of the hose
http://pics.tdiclub.com/showfull.php?photo=117811

Wide shot for orientation
http://pics.tdiclub.com/showfull.php?photo=117812
 
Last edited:

Mike_04GolfTDI

Top Post Dawg
Joined
Nov 19, 2003
Location
Richmond, BC, Canada
TDI
Mine: 2019 Golf R DSG, Wife's: 2015 Golf Comfortline TDI
Looking at the photos again, especially the first one, I think the leak is actually coolant migrating it's way to the end of the hose between the layers of the hose.

Perhaps during installation they nicked the inner layer, or maybe it is simply a poor quality hose.

I'm always afraid to take a car in for warranty repair. I almost want to just fix this myself, but I'm concerned about that flimsy plastic connection that the hose connects to. If that breaks then it becomes a gong-show. Let it be VW's gong-show.
 

meerschm

Top Post Dawg
Joined
Apr 18, 2009
Location
Fairfax county VA
TDI
2009 Jetta wagon DSG 08/08 205k buyback 1/8/18; replaced with 2017 Golf Wagon 4mo 1.8l CXBB
Any coolant leak on a year old car is an issue.

if it was me, I would take it in and have them fix it.

(and, of course, follow up to verify what they have monkeyed with......)

with three electric coolant pumps, and two different flow circuits, just getting the air out after changing a coolant hose may be more of an issue than you think...

(perhaps the actual tech will talk to you.....)
 

nectarguru

Veteran Member
Joined
Jul 25, 2011
Location
Milwaukee
TDI
Black 2015 Golf SE
Thanks for this. Just the other day I got my Golf back from the dealer for a coolant leak. Had it for a week and couldn't find anything...I'll have to start poking around myself.
 

Mike_04GolfTDI

Top Post Dawg
Joined
Nov 19, 2003
Location
Richmond, BC, Canada
TDI
Mine: 2019 Golf R DSG, Wife's: 2015 Golf Comfortline TDI
Nectarguru, are you saying that there's a leak, but the dealer couldn't find it? How do you know there's a leak? Low level in reservoir? Fluid on ground?
 

dubStrom

Veteran Member
Joined
Aug 6, 2007
Location
Kansas City Missouri
TDI
2003 A4 Jetta (sold), 2010 JSW (sold), 2013 Passat 6MT traded for 2014 JSW with 6MT-TOTALED in November 2016, 2003 ALH 5MT conversion (sold), wheezing 2015 GSW/DSG and a new 2021 Tacoma Access Cab 4x4 p'up
At ~12,000 last month I had coolant under the car after parking and warning light was coming on before I even noticed that. I refilled with about a pint of 50:50 G13:deionized water. The round reservoir was clearly PRESSURIZED when I opened it. I have not gotten in there to figure out where it is coming from.

Now, a week later, it is happening again. Clearly, I must deal with it this weekend. Gee. I wonder if that pressure is normal. I don't see why the system should be pressurized.

I do NOT like the complexity of the coolant system. At first, the idea of having a more "advanced" coolant flow system was a "good idea". Now, I am realizing that even with it's flaws, a simple one pump, one thermostat, two hose system might be an old idea whose time has come!!
 

RIP TDI

Top Post Dawg
Joined
Feb 16, 2000
Location
Santa Barbara, CA
TDI
'15 GSW SE 6MT...... '01 Golf GLS 5MT.... '96 Passat Variant....
At ~12,000 last month I had coolant under the car after parking and warning light was coming on before I even noticed that. I refilled with about a pint of 50:50 G13:deionized water. The round reservoir was clearly PRESSURIZED when I opened it. I have not gotten in there to figure out where it is coming from.

Now, a week later, it is happening again. Clearly, I must deal with it this weekend. Gee. I wonder if that pressure is normal. I don't see why the system should be pressurized.

I do NOT like the complexity of the coolant system. At first, the idea of having a more "advanced" coolant flow system was a "good idea". Now, I am realizing that even with it's flaws, a simple one pump, one thermostat, two hose system might be an old idea whose time has come!!
I hope this is not the problem.
 

adjat84th

Veteran Member
Joined
Dec 13, 2008
Location
Virginia Beach, VA
TDI
'01 Jetta TDI/'15 Golf TDI
When the coolant is warm/hot, there will be pressure in the system and you should slowly open the reservoir cap. This is an applicable practice to both my '15 and '01 TDI. Completely normal.

As for leaks, the water pumps on these looked to have an early design flaw, mine included. 55k miles later, and I've had zero issues after the first pump went out at 15k. The coolant system is complex, but not crazy once you've looked at it long enough :)
 

dubStrom

Veteran Member
Joined
Aug 6, 2007
Location
Kansas City Missouri
TDI
2003 A4 Jetta (sold), 2010 JSW (sold), 2013 Passat 6MT traded for 2014 JSW with 6MT-TOTALED in November 2016, 2003 ALH 5MT conversion (sold), wheezing 2015 GSW/DSG and a new 2021 Tacoma Access Cab 4x4 p'up
vacuum

. I think there was actually a minor vacuum last night when I opened it maybe 15 minutes after shut down. So it was drawing coolant from the reservoir as it should when it needs it. It took less than a pint this time. Upon casual inspection from above, I saw no spray around the reservoir top, and no coolant underneath the bottle. Something down lower is leaking. I have only put G13 with 50:50 distilled water on there so far, so VW dealership should not have any comments about that when I take it in this week.

But the problem persists. I see the coolant coming out under the right front area just under the radiator at the edge of the brush guard (I wouldn't call that a skid plate). It is Saturday, so I'll remove the thing and take a look. I am hoping for a bad hose connection. I might replace it myself if it looks relatively contained. But I will look closely for any evidence for cracks in the radiator. As complicated as this coolant "circuitry" is, a cracked radiator might actually be minor by comparison to other potential leak sources on that right side down there. I really miss my 2014 JSW.
 

dubStrom

Veteran Member
Joined
Aug 6, 2007
Location
Kansas City Missouri
TDI
2003 A4 Jetta (sold), 2010 JSW (sold), 2013 Passat 6MT traded for 2014 JSW with 6MT-TOTALED in November 2016, 2003 ALH 5MT conversion (sold), wheezing 2015 GSW/DSG and a new 2021 Tacoma Access Cab 4x4 p'up
Radiator?

Dealership has the GSW. No word as of closing time yesterday. They had it first thing in the morning but they did not isolate the leak by 5pm. It seems the radiator is the source. I saw no evidence of a rock or damage on the front side, but it looks like it is behind the air conditioning condenser anyway. I think replacement involves removing a lot of hardware. I hope it all gets reinstalled right. ALH is getting some road time!

Confirmed... radiator developed a leak under 12k!

Fixed, ready to be picked up.

...One day later- They overfilled the reservoir in anticipation it taking more in. Still overfilled a couple of days/commutes later. I will remove some to get it in the "range"
 
Last edited:

VaporDave

New member
Joined
Jun 1, 2023
Location
Oregon
TDI
2015 TDI Golf Sportwagen
2015 Golf TDI Sportwagen had coolant hose break, VW replaced it, the new hose broke in same exact spot a week later, could there be an underlying issue?
 
Top