Coolant blown out from expansion bottle

[Audi Fan]

That's not distilled water, that's just water that's got hot. You might have killed a few germs, but that's about it. If your tap water is mineral rich, then you're probably leaving a nice layer of mineral deposits throughout the cooling system and possibly making things worst.

What parts have you replaced, almost everyone having the problem described here has fixed the problem by just changing the heater matrix in the cabin. I don't think anyone had to overhaul the whole cooling system.

I think u need to go back to school .. to know how is destiled water made... It is not about some ''germs'' haha for kids I thought u will try google it but u even didn't... When u boil water and coold down u make destiled water simply it removes organic materials , salt especially which causing rust and removes minerals..
I know u trying to be smart but I have car since 2015 and I know almost everything about it and repaired almost all parts just this one needs..
And I have replaced it few months ago... And it is not some matrix ! (as weirdly everyone call sit.). but it is called -> heater exchange 5Q0819031B like Kel member said.. You should have CarProg2 catalog where all parts are there and shown and properly titled and named by VW-AG group

And trust me better check the whole coolant system because if one part of it is not cleaned at least , the dirt will quickly populate to the new part and you will have to exchange it again..

 

[Audi Fan]

No. @shocks is correct. If you boil water in a pot & then let it cool off, the minerals and salt are still in the original water. In fact, the concentration is even higher, because you evaporated some of the water.

To distill water, you need to boil it, then capture the steam, then cool/condense the steam and collect the water into a separate, clean container. You need a still.

Well of course that's what I did I have cover lid on cooking accessories of course I didn't left it open...

Again here is google results (by the way I do this 20 years as am 42) and my dad and people used to do this in old cars they never put an coolant only in winter...

Distilled water is made by boiling water to create steam, which is then condensed back into liquid form in a separate container. This process removes impurities from the water, such as minerals, salt, and organic materials.


Here are some steps for making distilled water at home:

1. Fill a pot a quarter of the way with water.
2. Place a baking dish in the water.
3. Invert a lid over the pot to help with condensation.
4. The condensed water will drip into the baking dish.

Distilled water is a type of purified water that can be cheaper and easier to make at home than buying it. It can remove more than 99.9% of minerals from water, as well as bacteria, viruses, and heavy metals.

 

[Audi Fan]

Why would anyone assume "of course that's what you did"?

This sounds like you were just boiling water and then turning off the heat.

Anyway, now if someone else reads these posts, they will know that distillation requires a bit more work than turning on the stove.

No no .. it is just one off.. as my coolant started disappearing this summer .. I have replaced heater about year ago it was somewhat ok and now again
I knew that water will be gone in one trip I just made only once ... I still have normal pink coolant in garage but when I realised that I was keeping topping up quite expensive coolant I was wasting... So I did 2 litres of destiled water yes it took ages, but that water gone from the car in two days driving... Problem would be if the water would stay inside car for months then it would be issue..

Back to coolant problem... So what I would be doing and suggest is that when it comes to coolant leak it needs checking the whole system
The car is now 10 years old parts degrading.. DPF and EGR is finished needs taking down or I might just do DPF and EGR delete creates only back pressure and destroying the engine.. I will have to check all radiators including inside heater radiator as I was hearing crackling or bubling coolant in the middle of the dash board where the radiator is.. I did one mistake , I have purchased K-seal coolant leak repair the 250ml of ''stop coolant leak '' mixture and I have it used 3 times so 3 bottles and I have feeling it blocked heater again...

 

[Audi Fan]

Hi guyyz solved the problem .. Had hole in rubber hose pipe under intake manifold.. near oil filter enclosure.. Ridiculous how audi designed it so badly.. There is metal bracket and piece plastic slotted into it and attached onto the engine for cable harness route.. it is ridiculous how all is tight .. So this metal bracket was pushing against this rubber hose for 10 years and as coolant gets hot it expands hose and when cools it shrinks so this was ongoing for decade and that metal was basically like knife and cut through the hose ! What I did was I disconnected the rubber hose from metal pipe where coolant circulates and I cut hose in same line where it was pierced I made straight cut and reattached hose onto the metal pipe and put back securing clamp ring.. So hopefully no more coolant loss ..

 

[luke j]

Oil cooler housing unit has a gasket that’ll leak coolant

 

[Adanrh92]

So... Hi everyone, i would love that some of the old thread guys could see this and reply, but i am ok with any info i could gather.

Golf MK7 15 TSI, i know its not a TDI, but its almost the same engine, just a little bit of differences, long story short, same problem, coolant of the expansion tank, just with revving, or from long trips.

I have changed everything posible on the coolant system, Thermostat Housing, water pump, heater core, even the oil cooler as part of the thermostat housing change, and pretty much same issue.

I am thinking i have a head gasket leak, i ordered a pressure tester and i will teste TDC for hg and Head, and BDC for Cylinder Bores.
Desperate and crying in the inside thinking my best scenario is a bad head gasket, second one is the Head, and third on Cylinder Bores (Block, which one requiere a new engine).

I have read on some posts, not many, that some Block from the Early MK7 numbered as 230 are known to have this issue, Warped block or Cylinder Bores cracked, i have no idea where the number of the block is located, but damn it, first VW, i liked it so so much, thinking on buying another one, and then this happens... well...

So just as a question, some of you guys got it fixed by changing the Heater Core, here in Mexico we do not use the Heater that much, do you think my radiator could be clogged? i doubt it, but if the pressure test tells me there are no issues with the Head or Block, i will remove it and get it unclogged (Here in mexico we have shops that are just for that), but, hardly think that will happen, i thin i have a head gasket issue or cracked block.

As a matter a fact the reason why i am so sure its head gasket, head or block is because i tried the plastic glove on the reservoir, i removed the cap of it, make sure the glove is well adjusted and deflated with a rubber band, and start the engine cold (better in the morning), and guess what, i got air inside it, even tough it not inflated correctly after 30 seconds, there was definitely air coming inside.

So, lets se what happens...

 

[heathy]

Thought I'd update what happened with my car and not good news. I ended up selling the car in June last year, took a bit of a hit on the car with the issue but was just glad to get rid of it. I think it was the head gasket. I did the sniff test again before I sold it and this time the engine was hot as I just did a short drive rather than revving up to temp for 10 mins or so and it immediately changed to yellow indicating exhaust gases in the system, so whatever was the issue wouldn't have been cheap to fix and I couldn't be bothered with the headache any more, car was on 115k miles and I wanted to change it this year possibly anyway so I got about 4k for it when I could have got about 7-8k private and working fine.

The whole experience has just put me off combustion engines to be honest and I've decided im getting an EV next, I know they aren't perfect but engines just have so many parts, towards the end of my ownership I was paying thousands a year in maintenance on top of fuelling and its not worth it, I'd never own a car for more than 4 years ever again, you keep them too long things go wrong too often and you are stuck with the bills and a worthless car. I'm currently in a Jaguar XF which is running good so far (touch wood) but I'm seriously considering switching to a EV soon, less parts to go wrong, far cheaper to run and faster then most cars, it's a no brainer to be honest. I used to really love my cars but after the whole coolant thing I've realised how disposable they are, you should never fall in love with them.

Back to the coolant I'd get the sniff test done but makes sure the engine is properly hot, I'd ignore the instructions that say to rev it up to temp and do it and instead go for a short drive, maybe give it 5 mins to cool and slowly open the cap to let hot steam and gases out, then put the sniff test in and turn the engine back on and give a few revs, mine immediately turned yellow when I did that unlike before when I first did it a couple of times.

My advice to anyone would be to do this test first before wasting money on parts and guessing. I wasted money on new heater matrix that was a pain in the arse to fit, new coolant tank, coolant change, multiple garages doing pressure tests and investigations that led to nothing. Just get the cheap sniff test and do that to rule out a head gasket or cracked cylinder head or just get rid of the car and cut your losses like me, clearly theres a common fault on the MK7/7.5 cars, I wouldn't buy another one.

 

[Cmpep]

I’ve had this issue for about 2 months now on my 2015 Golf SportWagen, I’ve burped the system numerous times and no fix. However I’ve been purging the system today, and decided to run a diagnostic at the same time. It threw the code P16C600 which is Heater support pump running dry. This causes air to be trapped on n the heater core. I’m going to bypass the heater support pump and will let yall know how that works.

 

[drewpul]

How did that go for you?

I recently got the same code. i’ll probably take it into the dealer and hope they’ll take care of it under the dieselgate warranty.

I’ve had this issue for about 2 months now on my 2015 Golf SportWagen, I’ve burped the system numerous times and no fix. However I’ve been purging the system today, and decided to run a diagnostic at the same time. It threw the code P16C600 which is Heater support pump running dry. This causes air to be trapped on n the heater core. I’m going to bypass the heater support pump and will let yall know how that works.

 

[Liam F]

Hi Gents, Did anybody get a definitive fix on this ?

My car has the following symptoms on my 2017 MK 7 2.0 TDI DSG 184Golf All track

Coolant system pressurises and blows out of the expansion tank on a short spirited drive circa 10 mins this is post being Vac bled at a VW main dealer. It does not appear to be related to a DPF regen

Heater is hot on both vents.
Matrix or heater core has been flushed.
All 3 coolant pumps and cambelt has been replaced.
Header Tank and cap replaced.
Thermostat has been checked.
Fans are kicking in at the correct temp.
Coolant sniff tested for hydrocarbons or exhaust gas. Test negative.

VW master tech says he is not sure what to do next and doesn't want to start randomly replacing Matrix, EGR valve Charge Cooler,Radiator as it could run into thousands of pounds.

I read on another forum that there is a coolant pipe from the cylinder head that has a non return valve that can fail that can cause these type of symptoms ?Does anybody have an experience of this ?

Any further suggestion appreciated the car has been with VW for a month !!

Thanks in advance

 

[Paul A3quattro]

100% you need a cylinder head I had same problem changed all the same parts you have
I eventually had cylinder head removed and had it pressure tested turned out to have an internal crack.
I'm sure if you Google what the engine code for vag cylinder head porous and cracking you probably find yours

 

[P2B]

100% you need a cylinder head I had same problem changed all the same parts you have
I eventually had cylinder head removed and had it pressure tested turned out to have an internal crack.

Not convinced a cracked cylinder head could pressurize the coolant but test negative for hydrocarbons and exhaust gas.

 

[JC94]

Hi everyone,
Hopefully some people are still active in this forum as I have been experiencing very similar issues, however, myself, VW and the dealership I bought the car from cannot fix the issue.

I have a VW Golf GTD (66 plate). There is a horrible gurgling sound coming from behind the dash - sounds like water sloshing. This sound only happens once the car has been on a 10+ minute drive and when the engine shuts off. It will also make this noise when you put the car into accessory mode. However, it does not make the noise in accessory mode when the car has not been used for 8 or so + hours.

There is essentially air getting into the system. It has been bled by VW multiple times, the heater matrix has been changed and there seems to be no coolant drop off. VW have carried out a block test (CO2 test), EGR coolant leak test, coolant pressure test and everything has passed. Once the system has been bled, you cannot hear the noise, but as soon as you use the car for 10+ minutes and turn the engine off, the gurgling will happen. They have ruled out a minor head gasket leak, egr cooler leak, because of the aforementioned tests. They have recently done a cylinder leak down test which also passed, however, the technician said it was 'inconclusive' because he could hear the noise whilst it was being carried out.

It was originally diagnosed by VW to have the heater matrix exchanged thinking the old heater matrix silica bag exploded/crud was in the matrix. Since the dealership changed it (VW genuine part) the noise still persists. VW are at a dead end about how to diagnose this now.

Judging by these forums, it would seem my issue is the heater matrix, but when the car hasn't been used, I put it into accessory mode, and the gurgling issue doesn't happen. If it was an issue with the heater matrix, then the gurgling would happen all the time(?).

Water pump was also changed at 70k miles (now at 76k). Any help / advice would be very helpful!

 

[Liam F]

Hi everyone,
Hopefully some people are still active in this forum as I have been experiencing very similar issues, however, myself, VW and the dealership I bought the car from cannot fix the issue.

I have a VW Golf GTD (66 plate). There is a horrible gurgling sound coming from behind the dash - sounds like water sloshing. This sound only happens once the car has been on a 10+ minute drive and when the engine shuts off. It will also make this noise when you put the car into accessory mode. However, it does not make the noise in accessory mode when the car has not been used for 8 or so + hours.

There is essentially air getting into the system. It has been bled by VW multiple times, the heater matrix has been changed and there seems to be no coolant drop off. VW have carried out a block test (CO2 test), EGR coolant leak test, coolant pressure test and everything has passed. Once the system has been bled, you cannot hear the noise, but as soon as you use the car for 10+ minutes and turn the engine off, the gurgling will happen. They have ruled out a minor head gasket leak, egr cooler leak, because of the aforementioned tests. They have recently done a cylinder leak down test which also passed, however, the technician said it was 'inconclusive' because he could hear the noise whilst it was being carried out.

It was originally diagnosed by VW to have the heater matrix exchanged thinking the old heater matrix silica bag exploded/crud was in the matrix. Since the dealership changed it (VW genuine part) the noise still persists. VW are at a dead end about how to diagnose this now.

Judging by these forums, it would seem my issue is the heater matrix, but when the car hasn't been used, I put it into accessory mode, and the gurgling issue doesn't happen. If it was an issue with the heater matrix, then the gurgling would happen all the time(?).

Water pump was also changed at 70k miles (now at 76k). Any help / advice would be very helpful!

No still no update my car is still with the main dealer they really seem to be at a a loss to diagnose the issue !!

 

[Mattuks]

Maybe my experience with a 2015 Audi A3 184hp diesel engine will benefit someone in the future...
Car had all servicing (including timing belt) done to the letter throughout it's life.
With around 75 thousand miles on the clock, I got a low coolant warning. I topped it up and thought nothing of it, and the problem didn't return for quite some time. Throughout the Summer months, coolant loss would happen once or twice a month. Low coolant warning would always come on when I started the engine. Always topped up with the same amount, 300ml. Could hear gurgling behind the dashboard, air entering in to a closed system. Heater not working.
Fitted a new auxiliary water pump and bled the system. Coolant blow out still persisted. New expansion tank cap, no joy either. System was 'pressure tested' which showed no loss of pressure.
By this time the car had 80k on the clock and it was five years since the last timing belt and water pump change. So they were swapped out, and we found the impeller was sticking on the old water pump. I got my hopes up, thinking problem solved...
Sadly not, coolant blow out continued. I read this thread and could see a lot of people had successfully solved the problem by replacing the heater matrix. Although some still had further issues with the coolant system/head gaskets etc
At this point, I'd lost faith in the car, so traded it in. Moral of the story? If I had my time again, I'd start by replacing the heater matrix.

 

[buto24]

Did anybody have same problem, coolant loss through expansion tank cap after change heater matrix?
Did topic get final conclusion?

 

[Adanrh92]

Did anybody have same problem, coolant loss through expansion tank cap after change heater matrix?
Did topic get final conclusion?

get it pressure tested first before replacing anything, check for bubbles on the coolant reservoir when checking every piston at TDC and BDC, once you make sure HG and cylinder bores are fine, continue with the diagnostic.

 

[Paul A3quattro]

HERE'S THE ANSWER
100 % cylinder head faulty.. I had same faults lasted over a year throwing parts at car I then sent cylinder head for pressure test and that was the problem. Replaced head, 1 1/2 years later still going strong with no issues

 

[buto24]

HERE'S THE ANSWER
100 % cylinder head faulty.. I had same faults lasted over a year throwing parts at car I then sent cylinder head for pressure test and that was the problem. Replaced head, 1 1/2 years later still going strong with no issues

But OP change head gasket and still same problem..

" Hi all, decided to share my pain with VW community after ~8 months of troubleshooting by VW (Australia). 2013 Mk7 Golf 110TDI is pushing coolant out from the surge tank. Looks like gases enter the jacket under load, accumulate and then rush up to expansion bottled causing it to overflow - overflow pipe is tiny and most of coolant is blow out through the cap threads and sprays around under the bonnet. Done so far to no effect by VW: replaced water pump, multiple cooling circuit pressure tests, replaced expansion bottle, replaced cylinder head c/w gaskets etc., replaced EGR cooler, replaced intercooler, performed engine compression test, replaced some weeping rubber hose. Any idea is appreciated. Love the car but got quite frustrated by now. Few more points: never ever had overheating or gauge temperature moving beyond 90degC; following each "blow out" can clearly hear "hissing" noise coming from the heater core suggesting pockets of gas travelling through the system. "

 

[Paul A3quattro]

When the gasket was in the process of getting replaced it good practice to send the head to machine shop for a skim and pressure test that's how you will find out if you need a new cylinder head. The heads are prone to internal cracks which will only show up with a pressure test

 

[buto24]

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?

It seems that head/head gasket is not root of problem?