Coolant blown out from expansion bottle

SkilledMilk

Member
Joined
Mar 31, 2018
Location
Glasgow
TDI
Leon MK3 (184) 2013
Matrix replacement shouldn't cost too much if done by an independent garage as it's a couple hours labour + the part. The main dealers quotes in the £1000's are based on it being a dashboard out job, which is not the case. You could always have a go yourself!
 

dejvid

New member
Joined
Oct 10, 2019
Location
Czech republic
TDI
GVII Variant 2,0tdi
Haven't replaced the heater core yet.
But I drove it 2-3k km and I was checking the DPF regeneration and afterwars I turned the heat on HI.
Result: not a single drop of coolant lost
Hi, can you explain the effect of switching the heater to HI?
Do you switch the heating on HI during regeneration or after? How long?
Thanks for the reply
 

Spipa

Active member
Joined
Jul 18, 2019
Location
Netherlands
TDI
Mk 7 GTD
Hi guys, an update from me:

After replacing the heater core, the heating worked perfect again. In the first couple of days, the coolant kept getting lower and lower, even after a short 10 min drive. I honestly felt devastated and paniced a little bit lol. But after like 3/4 days, the coolant level has stopped dropping and since then I have driven now about 1500km with multiple DPF regens and lost not a single drop of coolant since then. I am 100% certain that my problems have been fixed.

I would advise you guys to replace the heater core yourself, it is an easy job and only need 2 or 3 tools. When replacing it yourself, the cost will be €90 in total (just the heater core).
 

Kennyboy993

Member
Joined
Oct 6, 2019
Location
Leeds
TDI
2014 Mk7 golf gt tdi
Thanks for the update.

I have mine booked in for new matrix on Monday. I will report back


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Kennyboy993

Member
Joined
Oct 6, 2019
Location
Leeds
TDI
2014 Mk7 golf gt tdi
Around £550 all in by volks works in Leeds.

I’ll let you know final cost


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BirdmanofTas

Member
Joined
Aug 13, 2019
Location
Australia
TDI
2013 Golf Mk7 Highline TDI
Hi guys, an update from me:
After replacing the heater core, the heating worked perfect again. In the first couple of days, the coolant kept getting lower and lower, even after a short 10 min drive. I honestly felt devastated and paniced a little bit lol. But after like 3/4 days, the coolant level has stopped dropping and since then I have driven now about 1500km with multiple DPF regens and lost not a single drop of coolant since then. I am 100% certain that my problems have been fixed.
I would advise you guys to replace the heater core yourself, it is an easy job and only need 2 or 3 tools. When replacing it yourself, the cost will be €90 in total (just the heater core).
Hi @Spipa, some dropping of the coolant level is to be expected, as the system will take a little time to fill all the little air pockets left by the expulsion of the coolant when the issue occurs.. mine dropped from above the high mark on the tank to just below half way between min and max, but has stayed there for the approx 4000Ks since..
 

Spipa

Active member
Joined
Jul 18, 2019
Location
Netherlands
TDI
Mk 7 GTD
Hi @Spipa, some dropping of the coolant level is to be expected, as the system will take a little time to fill all the little air pockets left by the expulsion of the coolant when the issue occurs.. mine dropped from above the high mark on the tank to just below half way between min and max, but has stayed there for the approx 4000Ks since..
Hi BirdmanofTas,

I did read about others having their coolant level drop slightly after replacing the heater core, so at first I did not think weird about it. But in those 3 days the coolant went from max to below min like 3 times, that is why I started to worry lol.
 

AdrianC

Member
Joined
Jul 16, 2019
Location
Ireland
TDI
Golf VII GTD
Since replacing the core in mine, I've done 2000km approx and only now am I topping up the coolant level. Notice a slight drop off but nothing significant (about 200ml).
This was to be expected to squeeze out any air pockets.
I hope not to be filling it again for a long time.
Ill do a coolant flush during my next service - just to be sure.
I can tentatively say the issued is fixed.....
 

Kennyboy993

Member
Joined
Oct 6, 2019
Location
Leeds
TDI
2014 Mk7 golf gt tdi
New matrix fitted and so far so good - 400 miles since and no loss of coolant at all.

Heater much more powerful also which is a bonus


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Kamei1507

New member
Joined
Aug 29, 2019
Location
Holland
TDI
Seat Leon st 1.6tdi 12/2014
Had my cooling system flushed again cold air on non drivers side. Heater works full now. But still have oil temperature problems 120 degrees when driving 140/150 km/h before heater matrix problems 108 degrees think my oil cooler is bugged whith same crap that has the heater matrix plugged. I think eventualy i have to swap it too.
 

mm-rocco

Well-known member
Joined
Jul 31, 2019
Location
Netherlands
TDI
MK7 GTD 2016
After 5000km i have coolant-issues again. This time the coolant is not blown out after a DPF. The coolantlevel drops under minimum and the an alert is generated on the MFA. As soon as i loose the cap pressure is released and the coolantlevel rises again. I am thinking of the EGR-cooler now.....


I am still confident that the heater matrix was related to my problem, being the first part :)



https://youtu.be/Mi3BnMo_F7g

https://youtu.be/j9cVRIpoMP0

https://youtu.be/KYPoK3WRado
 
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Spipa

Active member
Joined
Jul 18, 2019
Location
Netherlands
TDI
Mk 7 GTD
After 5000km i have coolant-issues again. This time the coolant is not blown out after a DPF. The coolantlevel drops under minimum and the an alert is generated on the MFA. As soon as i loose the cap pressure is released and the coolantlevel rises again. I am thinking of the EGR-cooler now.....


I am still confident that the heater matrix was related to my problem, being the first part :)



https://youtu.be/Mi3BnMo_F7g

https://youtu.be/j9cVRIpoMP0

https://youtu.be/KYPoK3WRado
Dang, you’re really out of luck.. has the dealer inspected your car again? What did they say?
 

mm-rocco

Well-known member
Joined
Jul 31, 2019
Location
Netherlands
TDI
MK7 GTD 2016
Dang, you’re really out of luck.. has the dealer inspected your car again? What did they say?

Obvious the EGR-Cooler....inspecting the EGR is almost half the price of replacing the EGR. My dealership see's this as the next logical step.
 
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Kennyboy993

Member
Joined
Oct 6, 2019
Location
Leeds
TDI
2014 Mk7 golf gt tdi
Better news my end - 4 long trips in and no loss of coolant at all. Approx 800 miles.

Looks like this forum has saved me a huge amount of money and who knows how much grief....... thanks guys


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minu94

Member
Joined
Nov 12, 2019
Location
Bucharest, Romania
TDI
2.0 TDI 184 Cupa Leon 5F
After 5000km i have coolant-issues again. This time the coolant is not blown out after a DPF. The coolantlevel drops under minimum and the an alert is generated on the MFA. As soon as i loose the cap pressure is released and the coolantlevel rises again. I am thinking of the EGR-cooler now.....
I am still confident that the heater matrix was related to my problem, being the first part :)
https://youtu.be/Mi3BnMo_F7g
https://youtu.be/j9cVRIpoMP0
https://youtu.be/KYPoK3WRado
Any news? Did you manage to get it sorted out?
 

mm-rocco

Well-known member
Joined
Jul 31, 2019
Location
Netherlands
TDI
MK7 GTD 2016
Any news? Did you manage to get it sorted out?

Thanks for asking ! On friday my EGR Cooler will be replaced, this weekend i will do some testdriving and let you all know what happened. If this is not the solution i am lost ??!?!? The good news is that all the repairs have been been payed by de German dealer under extended waranty.
 

kisvamos

New member
Joined
Nov 15, 2019
Location
Hungary
TDI
VW Golf MK7 Variant 2.0 TDI 2014
Hello Guys,
This forum thread helped me a lot, because in case of my MK7 Variant (2014) CRBC engine the car made the same symptoms like it was mentioned before. Normally, the problem occurred during longer trips, when the DPF regeneration phase happened. It was clearly audible that the coolant boiling and head out towards the front right tyre (because there is and overflow pipe). Beside it, the car was unable to make hot air when I set to HI the climate. After changing the Expansion tank and the cap on it the problem occurred again, so I tried to look after maybe someone else has the same problem. Luckily you guys identified as a construction problem of MQB platform VW systems, means that the Heater matrix inside the cockpit is undersized, and prone to clogging. Of course the dealers told that it is sure that there is head gasked, water pump or thermostat error, but i believed you guys instead of them. So I have booked my car to a coolant specialist where they are changing heater matrix as a daily routine. After disassembling they stated that the original was totally clogged, means that the fluid from the EGR cooler was unable to flow through it, because of it, the overflow pipe activated and the boiling coolant generated overpressure inside the tank so, this caused the problem.
So, fingers crossed, waiting for the next DPF regenations and see how the things are working. The price of the changes with Nissens heater matrix was ~230Euro.
I will update you guys if I have any news.
 
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mm-rocco

Well-known member
Joined
Jul 31, 2019
Location
Netherlands
TDI
MK7 GTD 2016
Not very lucky here. After the replacement of the EGR Cooler i still had a pressure build up resulting in a blow out of coulant. My VW Dealer gave me 2 quotes: Head gasket and pressure test and head + head gasket + pressuretest. 2300 Euro and 4400 Euro. I claimed the coolant-problem within 6 months of buying the car so i have a claim now on the dealer who sold me the car.
 
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BirdmanofTas

Member
Joined
Aug 13, 2019
Location
Australia
TDI
2013 Golf Mk7 Highline TDI
Not very lucky here. After the replacement of the EGR Cooler i still had a pressure build up resulting in a blow out of coulant. My VW Dealer gave me 2 quotes: Head gasket and pressure test and head + head gasket + pressuretest. 2300 Euro and 4400 Euro. I claimed the coolant-problem within 6 months of buying the car so i have a claim now on the dealer who sold me the car.
Sorry to hear of the ongoing issue mm-rocco, have they checked the electric coolant pumps on the engine, one of them is in the coolant circuit for the heater etc, and one in the egr cooler coolant circuit.. they have a habit of the impeller spinning on the shaft of the motor, so reduced coolant flow..
best of luck with it.. i can say my golf highline has been perfect since the replacement of the matrix approx 6500K,s ago, so feeling lucky
 

Gottfried

Member
Joined
Nov 4, 2018
Location
Slovenia
TDI
Golf Mk7 variant
Ji guys. Thanks a lot for all helpful posts. Mine seems to be fixed by changing the heater matrix. My friend showed the difference by blowing in old and new part and the old one is substantially narrower apparently.

fingers crossed for rocco and kisvamos.
 

c@n

New member
Joined
Mar 22, 2016
Location
Turkey
TDI
1.6 TDi 105 hp
I have the same problem with my 2015 Seat Leon 1.6 tdi CLHA engine.

We changed pretty much everything but still no luck. Heater matrix included, but it is the OEM matrix, might help to replace it with Nissens.

I have no EGR and DPF installed. They all been deleted due to the mods I had.

Will update if I get any solution.
 

kisvamos

New member
Joined
Nov 15, 2019
Location
Hungary
TDI
VW Golf MK7 Variant 2.0 TDI 2014
I have a good News in my case. I am after 7-800 kms with two dpf regen cycles without any loss of coolant. I still believe that this was the problem in my case and maybe I was lucky because I did not used the car after the second occasion when the previous problem occurred. Maybe this saved the head gasket and the egr cooler as well.
 

minu94

Member
Joined
Nov 12, 2019
Location
Bucharest, Romania
TDI
2.0 TDI 184 Cupa Leon 5F
Not very lucky here. After the replacement of the EGR Cooler i still had a pressure build up resulting in a blow out of coulant. My VW Dealer gave me 2 quotes: Head gasket and pressure test and head + head gasket + pressuretest. 2300 Euro and 4400 Euro. I claimed the coolant-problem within 6 months of buying the car so i have a claim now on the dealer who sold me the car.
Rocco, can you take a picture inside the coolant expansion tank? I want to see how your coolant looks like in the tank and if there is any residue on the neck of the expansion tank.
 

minu94

Member
Joined
Nov 12, 2019
Location
Bucharest, Romania
TDI
2.0 TDI 184 Cupa Leon 5F
I have some questions too. I noticed at the car, the following symptoms:
After going on a long road at high speeds, it loses her coolant at the overflow, I guess that it is from high pressure. Also, what I noticed, even after a few hours when the car was stopped, there is still pressure in the expansion tank. If I open the cap, the pressure is released and the level of antifreeze in the tank increases quite a bit (even if the car is cold). I noticed at the neck of the coolant tank some deposits, plus a patch on the surface of the coolant (not oil). Any idea what that might be?
LE: Likewise, if I give it a hard run, but not sustained(for a brief moment), it increases the level of the coolant quite a lot, but not enough to get out. (Provided that the cold level of the coolant is close to minimum or halfway between minimum and maximum).

Here are the pics with the coolant tank and the deposits on the neck
https://ibb.co/QDD3c2R
https://ibb.co/DwCR8kV
 

shocks

Member
Joined
Jan 22, 2020
Location
Perth AU
TDI
Golf MK6 2.0TDI (103KW CFFB) Comfortline, Golf MK7 2.0TDI Highline (CRBC 110KW), Passat Alltrack Wolfsburg Ed. 2.0TDI (DFHA 140KW)
Ha Ha, looks like I could found this post a little bit too late and I may have made a mountain out of a molehill. Great info here from everyone who's contributed and I thought I'd share my experience so far with my 2013 MK7 Golf 2.0TDI currently sitting at 115,000km on the odometer (seems to be the trend here). The tail below is a bit long but I find detailed posts like these very insightful (although maybe not always helpful) when trying to diagnose issues I'm having. The general consensus here is that the heater matrix is the prime suspect but still, maybe my experience is of use to others.
About 3 months ago I turned my ignition on and got the low coolant alarm. I had no idea at this stage where it was leaking from so I topped up the coolant with some demineralised water. Like everyone else here, this reoccurred but after the second time I tracked it down to the expansion reservoir relief cap, suspecting a head gasket leak might be the issue, I got a gas sniff tester. I initially got a positive green result from the cold expansion tank before even starting the engine but dismissed that initially as I could not get a positive test again while running the engine as hard and as hot as possible (while stationary). I repeated the test a few more times over the coming days and each time only got the test to go green when testing cold right after opening the bottle, not while running. Thinking this might just be a TDI thing I tried it on my other Golf (also a TDI but an older EA188) and the result was exactly the same, green on cold, all good during an extended engine run at 2500RPM with AC running on a 42degC day.
So now I'm thinking maybe it really is a TDI thing so I repeat the test on two other TDI's belonging to friends (one a Skoda EA288 and the other an Audi EA188), no colour change whatsoever !!
So I did 1.5bar pressure test on the coolant system and it passed the 30min VAG recommended test duration and continued to hold pressure for 3 hours more before I stopped. I didn't have an adaptor to test the cap itself, so I decided to just replace the pressure relief cap on the expansion vessel as it seemed like the “low hanging fruit” option. I thought after 12 days of constant checking that I was home free but at the end of a 300km round trip I opened the bonnet and there was fresh coolant still running down the bottle. So, I get a large rag and some gloves and open the brand-new relief cap, no hiss or pressure was released but when I tested the air inside, bang, it instantly turned yellow, not green, yellow!
All doubts now gone and being the impulsive home mechanic I am, I proceed almost immediately to rip the entire engine apart to see if it’s the head gasket. I did do a bit of research before I came to this conclusion and although I did consider the EGR Cooler and Charge Air Cooler as a possibility for gas entering the system, I didn't think these were as likely as the head gasket given my yellow gas test result.
So long story short, the head gasket didn't have any signs of a cylinder to gallery breach, both engine block and cylinder head were dead straight (less than 50um over the surface which was the smallest feeler gauge I have). While I had it all off, I also cleaned everything up and did a dye penetrant crack test on the cylinder head and the engine block and all four cylinders. Furthermore, Everything in the engine looks great, no build-up anywhere other than a small amount of carbon build-up at the top of the cylinders.
This is my first head gasket and while the EA288 CRBC is an amazing piece of engineering, it's ridiculously convoluted in terms of the cooling and electrical circuits encircling the engine. Teardown and rebuild so far has taken me almost 30 hours and I estimate 10 more to complete the job (I'm doing the timing belt and water pump this weekend and that should be it before refilling the coolant and changing the oil). I've spent $460 aussie dollars on OEM parts (renews including the head gasket, head bolts, and seals for various bits and pieces). The timing belt and water pump parts cost about $600 but that was already a planned job before the first coolant loss. Timing belt interval here in Australia is 120K, possibly even 105K if you believe VW Australia. I only use genuine VW parts.
I also spent about $200 on some special tools for looking the cams, again this was an investment I made for the timing belt job prior to the coolant loss occurring.
So that's my story so far, I guess the questions is, will it be just the head gasket or will it be the EGR Cooler (another $510), could it be the intercooler (another $1200) or just the heater matrix (a mere $285).
Anyone who's exhausted all other avenues and it looking to take on the head gasket themselves, I'm happy to share or answer any questions you have. I'll keep you posted on my car once it running again. Dame, I'll be pissed if it turns out to be just the heater matrix, you don't even need a damn heater in this country :)
 

RIP TDI

Top Post Dawg
Joined
Feb 16, 2000
Location
Santa Barbara, CA
TDI
'15 GSW SE 6MT, '01 Golf 5MT, '97 Passat sedan, '96 Passat variant
(I'm doing the timing belt and water pump this weekend and that should be it before refilling the coolant and changing the oil).
Unfortunately, no new insight for you, but I do have one question: I assume your original water pump is the variable flow design with the sliding shroud. Are you replacing it with the same type or with a conventional non-variable type and is the variable type even available from your dealer or aftermarket source?
 

shocks

Member
Joined
Jan 22, 2020
Location
Perth AU
TDI
Golf MK6 2.0TDI (103KW CFFB) Comfortline, Golf MK7 2.0TDI Highline (CRBC 110KW), Passat Alltrack Wolfsburg Ed. 2.0TDI (DFHA 140KW)
Unfortunately, no new insight for you, but I do have one question: I assume your original water pump is the variable flow design with the sliding shroud. Are you replacing it with the same type or with a conventional non-variable type and is the variable type even available from your dealer or aftermarket source?
Yeah i agree there's nothing definitive in my experience so far, just thought I'd share my experience, especially the combustion air testing bit as I thought it's mad that both my golfs tested positive. I'm going to hold of on the heater matrix and see if it was the head gasket. That should be interesting, I clearly have a lot of combustion air getting into my system to get a yellow test result. Others are having this problem too, even after changing the matrix, and may want to know if a head gasket replacement has helped. As I said Ill keep you posted but I suspect due to the frequency that the regen cycle and heater matrix were the root cause.
On the pump, I've gone like for like, based on the electronic parts catalog I asked VW parts for PN 04L121011P but they gave me PN 04L121011L. It has a solenoid and shroud so I assume its variable. The existing is PN 04L121011 first gen I believe but I'll confirm that soon. Why do you ask, is there some known issue with the variable type?
 
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