Coolant blown out from expansion bottle

Spipa

Active member
Joined
Jul 18, 2019
Location
Netherlands
TDI
Mk 7 GTD
Hi Schultze,

So how many km have you driven now after replacing the heater core? And still no coolant boil out? And how severe is the coolant loss?

How often did the boil outs happen before you replaced the heater core?
 
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mm-rocco

Well-known member
Joined
Jul 31, 2019
Location
Netherlands
TDI
MK7 GTD 2016
Hi Schultze,

So how many km have you driven now after replacing the heater core? And still no coolant boil out? And how severe is the coolant loss?

How often did the boil outs happen before you replaced the heater core?

This info would narrow the search for a long term solution, i am so fed up with this problem !
 

Spipa

Active member
Joined
Jul 18, 2019
Location
Netherlands
TDI
Mk 7 GTD
Can any of you allready confirm that the blow out of coolant only accurs just after the DPF ???
I am 99% sure that is the case. Since the coolant overflow only happens to me after a dpf regen during highway journeys. I never experienced a coolant boil out without the dpf regenerating the night before.

If you think about it, have you ever had a coolant boil out after just city driving? Or like me, only after highway trips?
 
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mm-rocco

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Jul 31, 2019
Location
Netherlands
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MK7 GTD 2016
I am 99% sure that is the case. Since the coolant overflow only happens to me after a dpf regen during highway journeys. I never experienced a coolant boil out without the dpf regenerating the night before.

If you think about it, have you ever had a coolant boil out after just city driving? Or like me, only after highway trips?

@Spipa Only motorways......on citydrives or short drives the engine will not be warm enough to do a full DPF-cycle.....
 

mm-rocco

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Jul 31, 2019
Location
Netherlands
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MK7 GTD 2016
If you have a Blue Tooth CANBUS connector laying around you can use the free version of the VAG DPF app. I have been monitoring over 3000 kilomters now and i am convinced the the both are related...
 

Spipa

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Jul 18, 2019
Location
Netherlands
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Mk 7 GTD
@Spipa Only motorways......on citydrives or short drives the engine will not be warm enough to do a full DPF-cycle.....
So that supports the theory of the dpf regens being the cause of the problems. During city driving (even with engine getting hot) and higway trips without a dpf regen, everything is just fine for me. If we just could legally remove the dpf..
 

mm-rocco

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Jul 31, 2019
Location
Netherlands
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MK7 GTD 2016
So that supports the theory of the dpf regens being the cause of the problems. During city driving (even with engine getting hot) and higway trips without a dpf regen, everything is just fine for me. If we just could legally remove the dpf..

I think it is the clogging up of the heater core, heater matrix which is just behind the Partikel Filter. After the DPF proces extrem hot air is blown against the heater core, as there is no circulation cause of the clogging this could cause the certain blown out of coolant.


Removing the DPF is not an option for us :)


I hope Schultze can backup the theory by confirming his problem is gone after replacing the heater core AND he can confirm that his blow out of coolant problem was related to DPF as well.......of that is the case the solution would be nearby
 
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Spipa

Active member
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Jul 18, 2019
Location
Netherlands
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Mk 7 GTD
I think it is the clogging up of the heater core, heater matrix which is just behind the Partikel Filter. After the DPF proces extrem hot air is blown against the heater core, as there is no circulation cause of the clogging this could cause the certain blown out of coolant.


Removing the DPF is not an option for us :)
I hope that you are right, I just find it strange that the heating works completely fine when the dpf is not regenerating. If the heater core indeed is clogged, wouldn’t the heating be affected all the time? Not just during regen? My knowledge of cars is very limited but it doesn’t seem logical to me. I am waiting for my next regen to check the if the heating shows weird symptoms for me.
 

mm-rocco

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Jul 31, 2019
Location
Netherlands
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MK7 GTD 2016
I hope that you are right, I just find it strange that the heating works completely fine when the dpf is not regenerating. If the heater core indeed is clogged, wouldn’t the heating be affected all the time? Not just during regen? My knowledge of cars is very limited but it doesn’t seem logical to me. I am waiting for my next regen to check the if the heating shows weird symptoms for me.

I am not a mechanic either, i did a lot of reading about his problem and the heater core and DPF seems to be related. We will see what Schultze thinks after replacing the heater core.
 

mm-rocco

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Jul 31, 2019
Location
Netherlands
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MK7 GTD 2016
I hope that you are right, I just find it strange that the heating works completely fine when the dpf is not regenerating. If the heater core indeed is clogged, wouldn’t the heating be affected all the time? Not just during regen? My knowledge of cars is very limited but it doesn’t seem logical to me. I am waiting for my next regen to check the if the heating shows weird symptoms for me.

@Spipa Is you car still under warranty ??
 

mm-rocco

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Jul 31, 2019
Location
Netherlands
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MK7 GTD 2016
I hope that you are right, I just find it strange that the heating works completely fine when the dpf is not regenerating. If the heater core indeed is clogged, wouldn’t the heating be affected all the time? Not just during regen? My knowledge of cars is very limited but it doesn’t seem logical to me. I am waiting for my next regen to check the if the heating shows weird symptoms for me.

Last weekend i did a test with the heating. Just after the DPF-proces i turned on the heating to max and drove for about 10 minutes then i stopped and checked the engine bay, coolant reservoir. The coolant in the reservoir raise almost near the top far above mex but did not blow out. Hopefully this information helps with solving the puzzle..
 

Spipa

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Jul 18, 2019
Location
Netherlands
TDI
Mk 7 GTD
Last weekend i did a test with the heating. Just after the DPF-proces i turned on the heating to max and drove for about 10 minutes then i stopped and checked the engine bay, coolant reservoir. The coolant in the reservoir raise almost near the top far above mex but did not blow out. Hopefully this information helps with solving the puzzle..
Did your heating show anything weird or no difference compared to normal? And did you put on the heating during the regen or right after it finished?
 

Spipa

Active member
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Jul 18, 2019
Location
Netherlands
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Mk 7 GTD
Just went for a drive and paid attention to the heating.. the vent all the way to the left produced so much heat that it hurted when I put my hand for a long time against it.. the vent all the way to the right produced no heat at all eventhough I put the temp on maximum for both driver and passenger side.. the more I went to right, the less heat came from the vent.. so it looks like my heating is also showing problems even without dpf regen.. I have a service scheduled on the 23rd, I will ask them to replace the heater core and let’s hope it solves it once and for all..

I also noticed that after testing the vents when I pressed on the ‘off’ button for the heating, there was still some hot air coming out of the vent, is that normal?
 
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Gottfried

Member
Joined
Nov 4, 2018
Location
Slovenia
TDI
Golf Mk7 variant
Hello guys,

I see I am not the only one. I am getting ripped off by mechanics for a year.
My symptoms are the same: coolant blows for example at highway speed (110 kph), or usually after drive over a mountain pass. Every time I hear gargling, but I am pretty sure that it happens two or three times until light comes on.
They repaired head and replaced gasket, then installed new head, replaced coolant bottle, 2x water pumps, thermostats... with no effect. It was under limited warranty as it was a used car and had to pay around 1k € by now so I am preety pissed off.
Did anyone come to a solution yet?
 

mm-rocco

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Jul 31, 2019
Location
Netherlands
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MK7 GTD 2016
Hello guys,

I see I am not the only one. I am getting ripped off by mechanics for a year.
My symptoms are the same: coolant blows for example at highway speed (110 kph), or usually after drive over a mountain pass. Every time I hear gargling, but I am pretty sure that it happens two or three times until light comes on.
They repaired head and replaced gasket, then installed new head, replaced coolant bottle, 2x water pumps, thermostats... with no effect. It was under limited warranty as it was a used car and had to pay around 1k € by now so I am preety pissed off.
Did anyone come to a solution yet?

@Gottfried Welcome to the club !They have replaced quite a few things on your car !We are still waiting for a reply from schultze, he replaced the heater matrix (5Q0819031), i am almost convinced that should be the solution. We wait for Schultze first ! Another thing could be the EGR-Cooler.
 

mm-rocco

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Jul 31, 2019
Location
Netherlands
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MK7 GTD 2016
Not yet, I am waiting for Schultze or someone in the other thread to confirm that the problems have been solved by replacing it. But I would be surprised if it would cost more than €200/250.

Well, the item is "only" 80 EURO. The total cost depends on the instructions the garage follows. For some models they have to completely strip the dashboard. I found this video for a MK7 https://www.youtube.com/watch?v=Yh8BwjJgkiI
 
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AdrianC

Member
Joined
Jul 16, 2019
Location
Ireland
TDI
Golf VII GTD
I have just recently been monitoring and noticing that all of the vents On the dash have varying degrees of temperature.
This is while all are set at the same temperature and the engine is up to operating temperature.
So maybe the heater matrix/core failure is the answer..
 

mm-rocco

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Joined
Jul 31, 2019
Location
Netherlands
TDI
MK7 GTD 2016
I have just recently been monitoring and noticing that all of the vents On the dash have varying degrees of temperature.
This is while all are set at the same temperature and the engine is up to operating temperature.
So maybe the heater matrix/core failure is the answer..

Okido :) Just red your older posts, your problem is simular to mine.
 
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Gottfried

Member
Joined
Nov 4, 2018
Location
Slovenia
TDI
Golf Mk7 variant
Hi,

my friend, a mechanic did a forced DPF regeneration with computer and it did not overheat. I thought it might provoke an overflow.
Nevertheless I guess I will try the heater core. Seems one of few things I have left to do.
 

Spipa

Active member
Joined
Jul 18, 2019
Location
Netherlands
TDI
Mk 7 GTD
Hi,

my friend, a mechanic did a forced DPF regeneration with computer and it did not overheat. I thought it might provoke an overflow.
Nevertheless I guess I will try the heater core. Seems one of few things I have left to do.
Overheating (too high oil or coolant temperature) never happened to me either, it does not seem like that this problem causes that.. if you refill the coolant in time. The coolant boiling out of the expansion tank does not occur every dpf regen, probably every second or third regen it happens (to me).
 

mm-rocco

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Jul 31, 2019
Location
Netherlands
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MK7 GTD 2016
Yes took it apart a few days after, to check for leaks. Used less than 1 hour to get access to the heater core, and assemble everything again.

@DrSchultze We are very interested in hearing your findings, no more blow out's ??? Do you notice in difference in oiltemp and coolant temp ?? We all look forward to hear form you :)
 
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