# Another Leak: Coolant (Solved)



## Hadaak (Dec 25, 2008)

100.009 km and the coolant leak has gotten serious. I checked it yesterday and found out the pink coolant stuff has thickened and settled on the metal rail beneath the radiator. I also found a point on the radiator where the coolant seems to be coming from. I had this coolant leak since 11.000 km when I took it to Audi and they couldn't find anything. I guess it was not visible at the time. I also guess they never checked it thoroughly with a pressure test. I did have to top it from time to time. Lately I added 1 liter of Deionized/Demineralized Water. I have run out of g12+ coolant. I also think the leak is linked to when I use the heater or the AC. So next steps is to check the rad, maybe get it off if it's easy...


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## TT-driver (Sep 14, 2010)

Mine, 9.5 years, 142k km is starting to develop a thirst for coolant too.

Please keep in touch with regards to where the leak is and how the radiator can be replaced. I don't feel like taking it to the dealer. At the moment I drive it less than 3k a year. Spending a lot of money on a radiator and a timing belt soon.... to me it's not worth it any more. So for me it's diy or out.


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## Hadaak (Dec 25, 2008)

If I remember right you have a BWA engine too. I found the leak spot. I will have to remove the fan protection and take a closer look. I took some pics. You will have to look for pink gunk either under the radiator or somewhere in the engine bay. I too will not bother taking it to Audi for repair. DIY all the way 
So you haven't changed the belt yet? Not sure at what mileage you have to change it on the BWA. Mine is 6 years old now.


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## Hadaak (Dec 25, 2008)

or get a Forge alloy radiator for £693.00 :lol:

http://www.techautos.co.uk/forge-motors ... 2532-p.asp


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## Hadaak (Dec 25, 2008)

local website sells the bwa radiator at 155,32 € TTC I'll send you two  
https://www.oscaro.com/radiateur-du-mot ... 0017-470-p


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## TT-driver (Sep 14, 2010)

Yeah I own a BWA too. 142.000km. Belt is officially due at 180.000km according to Dutch Audi dealers. Still no age restriction as far as I'm aware. Not sure yet if the belt is diy or not. Can get it done for around 550 Euro at an VAG specialist.

It seems all similar VAG radiators start leaking somewhere low down, hidden. Don't know which brand to buy: Valeo, Nissens, NRF, Hella/Behr. Too many manufacturers. Prices range from 80 Euro to 200.


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## TT-driver (Sep 14, 2010)

http://www.mister-auto.com/radiateur-mo ... _g470.html


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## Hadaak (Dec 25, 2008)

What bothers me is the leak pattern ! No leak for the last two days !!! Something is making the system throw out somd amount of coolant in some kind of situation !! Maybe a coolant pressure issue. I read somewhere the expansion tank cap can be the culprit. The leak is coming from the radaitor but that's probably just some relief point. I'll have to check elsa/etka for this. 
Diagnosis Mode in on


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## TT-driver (Sep 14, 2010)

Kind of the same here. When the car was still in daily use, I sometimes had to add some coolant, like 100 or 200ml or so. Once or twice a year for the past couple of years. Back then, the car was covering 30.000km a year. Now I'm down to 3.000km a year (probably even less...) and still I have to top up. I now started to keep detailed track of what I'm adding: with a permanent marker on the bottle, indicating the level in the bottle and the date. No more guessing from here on. To be on the save side, I've filled up an old Spa bottle with 0.5l coolant, that I now keep in the car. (larger doesn't fit) I'm not expecting a sudden cloud of steam from the engine bay, but what ever leak is there might increase unexpectedly.

I do see some water on the under tray every now and then. But when I soak it up with a paper towel, it's white and doesn't smell like coolant. So it must be rain water. No clear signs of a leak yet. Could be the water pump too, I don't know. Oh the fun of owning an old complicated car... that I don't really need any more......BUT still like!


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## Hadaak (Dec 25, 2008)

so we"re on the same boat then :lol: I entered diagnosis mode when I saw the pink deposit on the metal frame below the radiator. The leak seems to be coming from the botton center of the radiator. I looked it up on ELSA and do not see any pressure relief valve or anything on the radiator. So the radiator must be leaking under pressure maybe. you should get under the car and look at the radiator. I alsa have a 1L bottle of demineralised water in the boot.I'll have to buy some G13 if I decide to remove the rad. Changing the rad seems to be an easy job according to ELSA. 
I've also read the coolant liquid should be flushed every 5-6 years !!!


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## TT-driver (Sep 14, 2010)

VAG says the coolant is 'for life'. They only don't specify which or who's life. Timing belt/water pump? Radiator? Who knows. 
I replaced my coolant bit by bit over a couple of days: take out what's in the coolant bottle, fill up with fresh. After the next drive do the same again. That way at least gradually a part of the coolant is fresh. And it's not expensive so I didn't mind spending a few litres diluting the old with new. At least new additives got into the system. 
The pressure release valve is in the blue cap on the coolant bottle.

Perhaps the temperature stress is larger during winter time? I'll check with a mirror on a stick top-down. I don't feel like removing the under tray on my drive way during winter time. And I don't have the equipment to lift the car and create a stable working situation. But leaking radiators and VAG -> common. So apart from monitoring... need to get well informed which brand of radiator I need to get and where to get it cheap. I have a VAG breakers yard virtually around the corner. I'm going to ask the owner, see what he says. A lightly used radiator is fine too. Some additional rust protection should increase life expectancy. If it would stay ok for another 5 years then it would be fine. By then the AC condenser will fail too, requiring replacement. And who knows how long the inter cooler will stay OK? :roll:


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## Hadaak (Dec 25, 2008)

TT-driver said:


> VAG says the coolant is 'for life'. They only don't specify which or who's life.


 :lol: :lol: :lol: I had a good laugh at this one :lol: 
I checked after coming home today and I could see water on the undertray. So the rad is leaking. I will change the expansion tank cap just to see. Elsa really makes the job of changing the rad look way too easy for me !!! I thought you needed to remove all the front to get to the rad. Not sure you can remove it just by unscrewing 4 or 5 screws !!! 
Next step is replace the cap then look for a rad. If you find any info about a reliable brand please let me know. I will look around too and update this topic.


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## Hadaak (Dec 25, 2008)

getting the tools 

http://www.ebay.com/itm/VAG-Tool-1921-C ... 84&vxp=mtr

VAG Tool 1921 Coolant Hose Clamp Pliers Plier for VW Volkswagen Audi


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## ZephyR2 (Feb 20, 2013)

You can usually locate the source of a leak by letting the car idle until its will up to operating temperature. By then the cooling system will have become pressurised forcing coolant out of any weak spots. You can normally smell the coolant first and them feel damp air on your hand. Sometimes it helps to look when its dark using a torch as this will highlight the source of any steam.
Hit and miss coolant loss when parked is often associated with the water pump, and is not unusual when you approach the time when your cambelt needs changing, which is good timing in some ways.


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## TT-driver (Sep 14, 2010)

@ Hadaak: will keep you posted.

@ ZephyR2: Mine and many other TT's always seem to smell after coolant. I don't think that 'Eau de G12+' smells so strong that 100ml a year is detectable with my nose.... Perhaps mine smells more after coolant now, I'll check next time I need the car. Might be some time next week. The hit and miss remark regarding the water pump: interesting!


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## Hadaak (Dec 25, 2008)

cool way to flush coolant :lol:


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## TT-driver (Sep 14, 2010)

I talked to the breaker's yard guy yesterday. He said there wasn't much difference between the various brands. So that wasn't much help. He said Valeo is often seen as the first fit. But they all seem go bad pretty fast anyway: rust on the clamping part that holds the plastic parts to the cooling element. 
Still haven't checked mine. Too much other house hold jobs....


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## Hadaak (Dec 25, 2008)

leak is calming down !!! I guess beacause of the warmer climate these days !
i'm buying this for a complete flush after checking/changing the rad.
i guess I'll go for a valeo rad if mine is really in a bad shape.
Wonder how many liters are needed for a full flush. I'll have to ask Miss Etka.

http://www.ebay.de/itm/ORIGINAL-Audi-VW ... Swd0BV1ra9


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## TT-driver (Sep 14, 2010)

I think miss Etka will say around 8 litres. So that's around 11 bottles of Chateau de G-douze in French terms, right? :lol:


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## Hadaak (Dec 25, 2008)

:lol: :lol:


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## Hadaak (Dec 25, 2008)

don't now if pre-mixed is better than pure G13 + mineral water. I guess it depends on the climat and the antifreeze percentage required but I don't feel like mixing stuff. The G013040MS is 50% mix.


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## tdi_van (Nov 13, 2014)

TT-driver said:


> Yeah I own a BWA too. 142.000km. Belt is officially due at 180.000km according to Dutch Audi dealers. Still no age restriction as far as I'm aware.


I changed mine at 83.000 km, with 8 year( when i bought the car). Dont think any bealt should run in the car ( in age) so long!

just my 2 cents!


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## tttony (Dec 21, 2014)

"pure G13 + mineral water" I think that you mean de-mineralised water. Distilled water, de-ionised water, demineralised water are the best to use to avoid any possible corrosion problems. I like to drink Evian but I wouldn't put it in my car LOL.


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## TT-driver (Sep 14, 2010)

tdi_van said:


> TT-driver said:
> 
> 
> > Yeah I own a BWA too. 142.000km. Belt is officially due at 180.000km according to Dutch Audi dealers. Still no age restriction as far as I'm aware.
> ...


I get your point. A lot of discussion has taken place on this one already. Belts are constantly being improved. 
I'm sticking to official VAG values: 
http://www.volkspage.net/technik/ssp/ssp/SSP_334_d3.pdf


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## TT-driver (Sep 14, 2010)

Hadaak said:


> don't now if pre-mixed is better than pure G13 + mineral water. I guess it depends on the climat and the antifreeze percentage required but I don't feel like mixing stuff. The G013040MS is 50% mix.


Haven't got my head around G12+/G12++ or G13?

Is G13 better or is it just an environmental thing?


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## Hadaak (Dec 25, 2008)

tttony said:


> "pure G13 + mineral water" I think that you mean de-mineralised water. Distilled water, de-ionised water, demineralised water are the best to use to avoid any possible corrosion problems. I like to drink Evian but I wouldn't put it in my car LOL.


I'll put some Badoit into it  Will make the Stronic gear change pop much better :lol: :lol:


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## Hadaak (Dec 25, 2008)

TT-driver said:


> Hadaak said:
> 
> 
> > don't now if pre-mixed is better than pure G13 + mineral water. I guess it depends on the climat and the antifreeze percentage required but I don't feel like mixing stuff. The G013040MS is 50% mix.
> ...


mmm don't worry everybody is looking for that G :lol: :lol: the quest goes on :lol: :lol:


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## TT-driver (Sep 14, 2010)

spot on!


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## Hadaak (Dec 25, 2008)

Finished the third bottle of water this week. I changed the expansion tank cap yesterday. I will get a G13 bottle to balance the mixture
Do yo guys know if there is any pressure management mecanism inside the cap. I will tear down the old one to see what's inside. The old one was getting easy to unlock but hard to unscrew. if the leak goes on I will order a rad and change it soon.


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## Hoggy (May 8, 2002)

Hi, There is a pressure relief valve built into the cap that opens at approx 23 psi. If that is leaking then coolant will gradually "boil" away, without you seeing any coolant under car.
Harold.


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## Hadaak (Dec 25, 2008)

Thanks Hoggy. I do see coolant under the car but the leak is not persistent. I mean there is something triggering it, it's not happenign on every trip. I'm thinking there is a lack of pressure relief somewhere which makes the coolant force its way through the rad somewhere. Is there such an emergency pressure relief point on the rad somewhere?


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## Hoggy (May 8, 2002)

Hi, Only pressure relief is in the reservoir cap & if that is working correctly temp gauge will be round the clock before that lifts, but of course could be lifting early & blowing coolant/vapour out through relief valve pipework.
Have you had the system pressure tested when hot ?
Hoggy.


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## Hadaak (Dec 25, 2008)

Audi did two tests a long time ago. they found no issue. when car was 12.000 km and later around 30.000. first time the expansion tank was almost empty. they refilled then nothing until around 20.000 later. There was no coolant apparent on the undertray. now I see coolant and I have to refill from time to time. I see where the leak is coming from. bottom middle side of the radiator. I will see if changing the cap will regulate pressure but if the rad is punctured I guess it is just a matter of time before things get worse. What I don't understand is the randomness of it ! so still looking for pattern... I know it got bad last winter when it was very cold around here.


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## TT-driver (Sep 14, 2010)

All I can imagine is a tiny opening in the radiator that is temperature dependent. Perhaps when the radiator is hot, it closes itself and when it's cold, it is dripping.

The radiator is part aluminium, part plastic and part iron/rust. These 3 materials don't behave the same under temperature fluctuations. I didn't drive since the last top-up 2 or 3 months ago. And no change in coolant level. So mine doesn't seem to leak when the car isn't used. Just checked while I was cleaning up the mess that this spring had caused again. Junk (some call it blossom) from trees, pollen and what have you. :evil:


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## brittan (May 18, 2007)

TT-driver said:


> All I can imagine is a tiny opening in the radiator that is temperature dependent. Perhaps when the radiator is hot, it closes itself and when it's cold, it is dripping.


Yes, that's my thought too: a small defect which leaks when the combination of system pressure and temperature are "just right".

Careful with the blossom! Last year I evicted the TT from the garage to dig up and replace the floor. Some blossom from one of my trees settled on the car and I just left it. When I did wash it off I found that the petals had left a 'shadow' on the paint that required machine polishing to remove.


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## TT-driver (Sep 14, 2010)

I know. TT escaped unharmed again 

But I do wonder where all the junk from a beech trees ends up that creeps in the area between the wings and the body. You know where the wheel well cover sits and the washer bottle lives. Does it escape somehow, or is it building a compost heap in there?


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## brittan (May 18, 2007)

Definitely a compost heap. 
Next time you open the bonnet you may be greeted by a beech sapling.  :lol:


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## TT-driver (Sep 14, 2010)

Ah that explains










Always great help, the TT forum. :lol:

Back to hadaak!


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## Hadaak (Dec 25, 2008)

:lol: :lol: :lol: :lol:


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## Hadaak (Dec 25, 2008)

so the new cap reduced the leak I guess or is it just wishful thinking  i guess I'm good for a new rad. I will take a look one last time under the car before ordering a new rad.


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## TT-driver (Sep 14, 2010)

Do keep us posted


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## Hadaak (Dec 25, 2008)

Just for the record:
Radiator part number for the BWA 2L TFSI (2009) : 1K0121251AB


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## TT-driver (Sep 14, 2010)

Past two months: not a drop has disappeared. Both from the coolant bottle, nor from the fuel tank.

Guess my radiator will stay in the car for a little while longer.


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## Hadaak (Dec 25, 2008)

Are you driving it every day?

Was looking for info on radiator removal and came across this : a guy changing timing belt on a TT1 is also changing the coolant expansion tank. Might be a good idea if I have to flush the coolant and if it is not a pain to remove. the picture shows a new tank and a 6 years old one. Not sure on the real benefits  or is it only for looks :mrgreen:


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## TT-driver (Sep 14, 2010)

Hadaak said:


> Are you driving it every day?


I used to. 130km daily, motorways. Then I lost my job. that was two years ago. Since then it drove 4.000km.

So.... I _look_ at it daily. And I spend more time cleaning it than driving it. And I cover more distance on bikes than in a car. Better for my health, no parking dents and scratches. My TT was never meant to be a shopping trolley, so I'm not turning it to one now. Only long distance motoring.

My coolant bottle isn't as brown as the one in the picture. Couple of years ago, I flushed the contents of the bottle for a week every day. Suck out the old coolant, top up with fresh. While it wasn't a full flush it did approximately refresh around 70% of the coolant. That may have helped keeping that bottle white-ish. Although none of the coolant was ever brown.


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## Hadaak (Dec 25, 2008)

Nice technique. I will flush the system when I change the rad. Not sure I will change the tank


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## WoRkZ (Sep 19, 2015)

The tank get's darker with time because the plastic ages and tends to become more opaque/yellowy. Plastic made with lead would not do that... but I hear lead is not such a popular chemical these days. :wink: :lol:


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## Hadaak (Dec 25, 2008)

shopping for a radiator. prices vary from 70 to 160€. Any brands to recommend? The only one I know is Valeo


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## Hadaak (Dec 25, 2008)

Code moteur : BWA
Épaisseur [mm] : 34
Équipement véhicule : pour véhicules avec système de climatisation
Hauteur [mm] : 650
Largeur [mm] : 454,3
Ø admission [mm] : 32
Ø sortie [mm] : 32
Type de boîtier : Boîtier plastique
Type d'entraînement : boîte de vitesses manuelle
Type d'entraînement : Boîte automatique

114,68 € TTC


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## Hadaak (Dec 25, 2008)

Guess it's gonna be a Hella for around 155€


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## TT-driver (Sep 14, 2010)

See my post dated 4 march (first page of this topic)


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## TT-driver (Sep 14, 2010)

WoRkZ said:


> The tank get's darker with time because the plastic ages and tends to become more opaque/yellowy. Plastic made with lead would not do that... but I hear lead is not such a popular chemical these days. :wink: :lol:


For some, it's a fine metal in the right foot :lol:


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## Hadaak (Dec 25, 2008)

TT-driver said:


> See my post dated 4 march (first page of this topic)


I remember that post. I did some reading and the Hella is the one I'm getting.


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## TT-driver (Sep 14, 2010)

Lot cheaper than 155 euro, or not?


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## Hadaak (Dec 25, 2008)

French website 155€ for the Hella.


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## Hadaak (Dec 25, 2008)

I'm finding the same part number (1K0121251AB) with different dimensions !!!
this is the pic from ETKA: Rad is number one 

http://etka.cc/tvn_result/search/tvn/1K0121251AB


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## TT-driver (Sep 14, 2010)

Sorry, looked at the wrong size there....

Just checked my notes on the TT and a couple of months ago I narrowed it down to these two from Hella:
8MK 376 774-031 or 8MK 376 774-041.

Which? Not sure yet....


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## Hadaak (Dec 25, 2008)

I did check on the hella website and they list 4 models. the specs of the two you found are :

8MK 376 774-031 
Length: 650 mm, Width: 451 mm, Depth: 34 mm, Vehicle Equipment: for vehicles with air conditioning, Heating / Cooling: *for vehicles with heavy duty radiator*, Version: produced by AKG

8MK 376 774-041
Length: 650 mm, Width: *445 mm*, Depth: *32 mm*, Vehicle Equipment: for vehicles with/without air conditioning, Version: produced by AKG

there are two other models which are listed as 
_
- - BEHR HELLA SERVICE Version ALTERNATIVE -
The alternative for repairs in relation to the current
value of the car
_

these two other versions are variations of the base two ones listed above (031 and 041)
031 has a service model => 034
031 has a service model => 044


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## Hadaak (Dec 25, 2008)

the pic from hella website

http://www.behrhellaservice.com/behr-hella-service/en/Cooling-system-5069.html


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## TT-driver (Sep 14, 2010)

"The alternative for repairs in relation to the current value of the car"

sounds like a low quality cheap replacement.... to fix up the car so it can be driven to the junk yard...

So I guess it's 'get the tape measure and check out the dimensions time'. I wouldn't be surprised if it's the heavy duty one.


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## Hadaak (Dec 25, 2008)

exactly what I thought and exactly what I was going to do tonight


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## Hadaak (Dec 25, 2008)

The heavy duty version sounds funny though :lol:


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## Hadaak (Dec 25, 2008)

I took a look this morning at the engine and it is not possible to measure the dimensions of the radiator


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## TT-driver (Sep 14, 2010)

not even just the depth? 32 or 34 mm? 
And that the radiator hoses are on the right spot?


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## Hadaak (Dec 25, 2008)

I noticed a difference in hose connection between versions. I will check that later today.


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## Hadaak (Dec 25, 2008)

I managed to get the right part number yesterday. I checked the leak spot under the car and came upon a sticker on the bottom of the radiator. And guess what, it's a Valeo :x the sticker says Valeo RA 1365 with VW part number 1k0121251AB. The leak is coming from a damaged spot. I don't know how this happened ! There is a dent on the leak spot like someone tried to push a screwdriver through the rad !! I will have a clearer vision when I take it off. So I looked up the corresponding Hella part number and came up with this: 8MK376774041. The rad seems easy to remove so I'm ordering the Hella one today plus 10L of g13 coolant. Replacement operation will be carried out next weekend.


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## Hadaak (Dec 25, 2008)

Hella 8MK376774041 ordered today. 160€ delivered. Next step is to get some G13.


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## Hadaak (Dec 25, 2008)

3 litres of G13 secured 
Launch scheduled for next sunday :lol:


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## Hadaak (Dec 25, 2008)

I can't get hold of the necessary amount of distilled water to flush and refill so radiator replacement is postponed to next weekend. I should have bought the pre-mixed vw coolant. Or I'll have to distill water myself


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## Hadaak (Dec 25, 2008)

Looks like shouldn't have used deionized wated

http://www.finishing.com/147/97.shtml


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## brittan (May 18, 2007)

The workshop manual says, "Use only clean tap water for mixing coolant."

This info: http://www.theaa.com/motoring_advice/ge ... olant.html says:
_High levels of calcium and magnesium in tap water, that cause furring of kettle heater elements, can also lead to deposits and scale build up in the engine cooling system. If you are in a hard water area it is advisable to use distilled or deionised water in the cooling system rather than tap water._

If you pour deionised water from container to container or just agitate it, it should absorb CO2 from the air which will neutralise the H+ ions and raise the pH towards neutral (pH 7).

Since the deionised water is mixed with G13 I would expect its corrosion effect to be significantly reduced anyway; that's one of the properties of the coolant G13.

If you've already filled the system it may be worth emptying the reservoir and refilling with fresh G13 mix, run the car and repeat a few times, even if that's just for peace of mind.


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## Hadaak (Dec 25, 2008)

thanks for the info. I haven't changed the rad yet. i will flush the system and refill it properly when changing the rad next sunday. I got 15 L of distilled water to clean and fill the system.


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## Hadaak (Dec 25, 2008)




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## Hadaak (Dec 25, 2008)

Here is what you need to do it the right way :

http://workshop-manuals.com/audi/a2...g_system/draining_and_filling_cooling_system/


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## Hadaak (Dec 25, 2008)

I'm buying this tool to make it easy to do the flushing/refilling job:

https://www.amazon.co.uk/Laser-4287...d_cp_60_1?ie=UTF8&refRID=ZKPRXFBF60WQ5MHK3YF0


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## Hadaak (Dec 25, 2008)

111 €


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## TT-driver (Sep 14, 2010)

brittan said:


> If you pour deionised water from container to container or just agitate it, it should absorb CO2 from the air which will neutralise the H+ ions and raise the pH towards neutral (pH 7).


As far as I'm aware it's actually the other way around: pure PH 7 water absorbing CO2 will do this:

2 H2O + CO2 --> H2O + H2CO3 (carbonic acid) --> (H30+) (charged acidified water) + (HCO3-) (charged bicarbonate ion)

The PH value will drop.

G13 has a PH that is in the range of 8 to 8.5, approximately. It will therefore neutralise the slightly acid water. So no need to worry there.


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## Hadaak (Dec 25, 2008)

Radiator changed today. Details and test results coming soon.


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## TT-driver (Sep 14, 2010)

Did you post that at 01:17? After a hard days work?

Looking forward to the details


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## Hadaak (Dec 25, 2008)

Yeaaah hard one but full of satisfaction  Undertray is clean now  details when I have some time. Cheers !


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## Hadaak (Dec 25, 2008)

Hella radiator is dying. It is leaking much more than the oem valeo one used to do. 
Bought on june 14th 2016.
Started leaking hard on all of a sudden june 17th 2018.
So it lasted 2 years.
Maybe it tool a hit on the road. Maybe not.
Not buying any Hella stuff again if I find out it died because of a quality issue :-(


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## Hadaak (Dec 25, 2008)

Just to update the thread. I Put a valeo radiator a week ago. Working fine. I hope it will last more than the hella which did 2 years.
If you guys need to change the radiator you better get these coupling parts as well since they are a pain to remove:
Quic acting coupling: 7M3122291 (6€) /1K0122291L (10€). This is for the BWA engine. and just unplug the hoses and leave the couplings on the radiator. put the new coulplings pieces on the new radiator and plug the hose when you install the rad. nice and simple. I did it twice and had to fight twice with the coupling monsters.

Since I did this twice and will have to flush the coolant for the third time for the belt/thermostat change I decided to add a coolant flush/purge/bleed mod. I'm adding a coolant temp T piece to the hose just before the connection to the radiator on the feed side (left on the BWA engine). I will use the temp port as a purge/flush outlet. I might have to overthread it to have a better flush flow. Flush port direct downward of course


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## Hadaak (Dec 25, 2008)

Pic of the couplings. This is the feed side. 6€


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## Hadaak (Dec 25, 2008)

The t piece I'm talking about:
I will have to check the diameter of the hose.


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## Hadaak (Dec 25, 2008)

This is the feed side. 10€


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## Wolvez (Jun 22, 2018)

The best way to find a leak is by using UV Dye. Pressure test will only detect liquid leak. It will not detect vapor leak. A very small leak in the Oil Cooler and DSG cooler could also be very difficult to detect. If your using Silicone Coolant Hose you will loose a lot of water even there is no leak due to high permeation.


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## Hadaak (Dec 25, 2008)

I don't have any leaks and TT hoses are stock. I fixed the leak issues anyway. radiator damaged in the first case and bad radiator in the second case. I'm adding the temp adaptor as a flush point to make it easy to flush the coolant on any operation which requires coolant flush like the oncoming timing belt change and thermostat replacement.
Thanks for the info.


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## Wolvez (Jun 22, 2018)

Hadaak said:


> I don't have any leaks and TT hoses are stock. I fixed the leak issues anyway. radiator damaged in the first case and bad radiator in the second case. I'm adding the temp adaptor as a flush point to make it easy to flush the coolant on any operation which requires coolant flush like the oncoming timing belt change and thermostat replacement.
> Thanks for the info.


Flushing or draining coolant will be a lot easier. The problem is when hose connection leaks or fails, there's no stopping hot coolant from going out. Flushing coolant will not clean your cooling system unless you remove the drain plug on the engine block.


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## Hadaak (Dec 25, 2008)

Not sure what you mean by the drain plug on the engine block. There is none. Here is how I did it for the two radiators I changed: You go under the car, pull the hose out and get soaked in coolant, well you make a mess at least. What I intend to do is add a plug with the T adaptor. The temp sensor port will be directed downward. So next time I want to drain the coolant system, i.e removing a big amount of coolant before opening any part which uses coolant like the water pump or the thermostat I will not make a mess. I will just have to remove the drain plug (plug which replaces the temp sensor on the T adaptor) and wait for the coolant to stop dripping out of this port. I don't intend to use this as a flushing system. The temp adaptor is apparently well made and if clamped correctly will hold like any hose connection. I plan to use the spring band clamps like the oem ones on the radiator couplings but I have to find ones with the right diameter as the oem ones fit over the end of the hose which has a bigger diameter than the inside of the hose.


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## Wolvez (Jun 22, 2018)

Hadaak said:


> Not sure what you mean by the drain plug on the engine block. There is none. Here is how I did it for the two radiators I changed: You go under the car, pull the hose out and get soaked in coolant, well you make a mess at least. What I intend to do is add a plug with the T adaptor. The temp sensor port will be directed downward. So next time I want to drain the coolant system, i.e removing a big amount of coolant before opening any part which uses coolant like the water pump or the thermostat I will not make a mess. I will just have to remove the drain plug (plug which replaces the temp sensor on the T adaptor) and wait for the coolant to stop dripping out of this port. I don't intend to use this as a flushing system. The temp adaptor is apparently well made and if clamped correctly will hold like any hose connection. I plan to use the spring band clamps like the oem ones on the radiator couplings but I have to find ones with the right diameter as the oem ones fit over the end of the hose which has a bigger diameter than the inside of the hose.


Use this 2 piece thermostat assembly instead.


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## Hadaak (Dec 25, 2008)

Funny I need to replace that too 
It failed (open state) a long time ago.


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