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Discussion Starter · #1 ·
hi folks, first post here. I tried looking about but couldn't find quite this issue:

What you're looking at there is my phone hovering over the opening of the coolant reservoir. Coolant looks clear, though the reservoir is admittedly dirty. When the car is started, you see white clouds forming in the coolant.

I recently bought the car and unless someone can point me at an obvious solution, it's going back to the garage methinks. I don't know that I can stand this sort of headache, lovely though the car is :(

Ninja Edit: most I've driven it is 50 miles. Temperature was fine, bang on 90c even with AC on.
 

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TBH I can't say that I've paid that much attention to coolant activity with the engine running lol. I mean it could just be time for a coolant flush. However there may be a problem as well. You could get a block tester and see if it's combustion gasses that are combining into the coolant--this would indicate a head gasket issue, which I probably don't have to tell you is a serious problem.

A note about the "bang on 90C" bit. VAG cars are actually designed to indicate 90C even if the temp is like 110C, so it's not really that great an indication. That's why the gauges are so steady in these cars, they're not true indicators of coolant temp. They will of course start indicating correctly when you get closer to overheating but within a range it just indicates 90C.
 
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Discussion Starter · #3 ·
TBH I can't say that I've paid that much attention to coolant activity with the engine running lol. I mean it could just be time for a coolant flush. However there may be a problem as well. You could get a block tester and see if it's combustion gasses that are combining into the coolant--this would indicate a head gasket issue, which I probably don't have to tell you is a serious problem.
lol - I wouldn't usually either... That's the thing though, the coolant was recently (2 weeks ago) flushed. Hence my concern... I'll ask the garage if they used a block tester before getting too much paranoia.

A note about the "bang on 90C" bit. VAG cars are actually designed to indicate 90C even if the temp is like 110C, so it's not really that great an indication. That's why the gauges are so steady in these cars, they're not true indicators of coolant temp. They will of course start indicating correctly when you get closer to overheating but within a range it just indicates 90C.
lol, yeah - I meant more like it was staying at the top and not veering. I haven't had it for a long drive or ridden it hard yet, so I don't know what that would do...

I should also ask - does it sound right for a 3.2?

Thanks.
 

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The whole system was flushed recently though. Would there be any G12 left? Also, both should be transparent, not result in a milky mess?!
YUP, impossible to drain the coolant inside the engine because they deleted the drain plug on the engine block. Contrary to the manufacturer's claim, G12 & G13 are not compatible. When those 2 coolant mixed silicate (sand) dropout will occur.

You can test the cooling system using a rubber gloves and rubber band. If combustion is leaking on the coolant it will inflate the gloves very quick.
 

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Discussion Starter · #7 ·
YUP, impossible to drain the coolant inside the engine because they deleted the drain plug on the engine block. Contrary to the manufacturer's claim, G12 & G13 are not compatible. When those 2 coolant mixed silicate (sand) dropout will occur.

You can test the cooling system using a rubber gloves and rubber band. If combustion is leaking on the coolant it will inflate the gloves very quick.
That’s a great tip, thank you!
 

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Back in the day, the term "Coolant Flush" meant you bought an inexpensive Prestone flush kit, spliced a t-connector into one of the heater hoses, then opened the valve on the bottom of the radiator and literally flushed the entire cooling and heating system using a garden hose and lettting it run for 5 minutes or so. See the Prestone flush kit below.

Even with this method, there was probably some fresh water still in the block or cooling system, but the idea was to literally flush all the old coolant out. I'm not sure how the shops do a flush on a VAG cooling system unless they have an adapter for the overflow bottle where they can connect a fresh water line and then pull the lower hose off the radiator...??

Just an FYI -

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Back in the day, the term "Coolant Flush" meant you bought an inexpensive Prestone flush kit, spliced a t-connector into one of the heater hoses, then opened the valve on the bottom of the radiator and literally flushed the entire cooling and heating system using a garden hose and lettting it run for 5 minutes or so. See the Prestone flush kit below.

View attachment 487861
LOL I remember those from back in the 90s myself. Was a bad idea to use them really since you had to cut hoses and splice in such connectors which could just create another point for leaks/failure. Plus the idea was to flush with a garden hose, which is somewhat undesirable as you throw a lot of mineralised water in there that way. If one had a water softener or filtration system ahead of their garden hose piping though, that would be one way around it.

That said I did flush cars out as a kid with a garden hose--removing the thermostat and an appropriate hose and spraying through, as well as "autoflushing" by running the car and having it pump out the flush stuff. It worked and everything but I think these days we're more concerned about keeping minerals out for long term reliability. I guess one could flush with a pump and some gallons of DI or distilled water.

But yeah it's tough to get all the coolant out of many cars which lack additional drains like they had more of back in the day. Granted some cars still have multiple drains but VAG cars are funny, some (like the TT and most transverse 2.0T cars) we don't even get a radiator draincock! Never mind block drain or any other drain points. Radiator drain procedure is simply to remove the hose :LOL: I mean yeah it works, but c'mon.

Anyway I didn't think of the colour difference for G13 v. G12++. It is a slightly darker colour so maybe that is the cause of the "clouding" but you'd think it would all have mixed after a while, causing it to become one "mixed" colour. Unless it was really just drained/filled like a day ago or something.
 
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Hang on a sec. Everywhere I’ve researched about G12 and G13 says they are miscible - dunno why manufacturers would lie


View attachment 487874
G12++ and G13 are always cross-compatible. G13 and G12++ can also be added to any of G11 onwards without issue (or so VAG tells us). However you can't add G12+ (or G12 or G11) to a car that started with G12++ or G13. Well you can use G12+ but as shown above you lose some anti-corrosion, so it's not recommended except in a pinch. However since you really can't get G12+ or any of the earlier ones very easily anymore, it's not likely you're going to find G12+ to add into a G12++/G13 system anyway. Also coolant seems to be a product that has a finite shelf life as Prestone (for example) even states that sealed and unused coolant should not be used after 4-6 years (depending on the coolant type). So this means even if one had an "old bottle of G12+ lying around", they shouldn't use it anyway--just take it off to the HHW to dispose of.

Basically you can almost always use the newer coolant in the older system but not vice-versa. The one glaring exception is G11 & G12--you cannot add G12 to that but you can add G12+ and later to it. G11 is also a different colour though and will turn brown if you add G12+, ++, or 13 to it. It's recommended either to just keep using G11 (which I believe is still manufactured at least in the aftermarket), or flush out the G11 system and replace entirely with G12++ or G13.
 
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Quite funny to read about expiration or shelf life of coolant bottles, especially when Audi claim coolant is yet another lifetime fluid 😂
Yeah that and the transmission fluid in the automatics (like actual automatics, not DSGs). Meanwhile you ask ZF, the manufacturer of those transmissions and they basically say, "Lifetime? Hell no who told you that?" :ROFLMAO:

Same thing was actually the case with the Haldex in transverse cars...Originally Audi didn't have an interval, denied there was a filter (on Gen 2s and 4s, there really isn't one on Gen 5), and basically said it's fine for life. You asked Haldex (now BW) and they were like, "Huh? No, it has to be changed!" Later Audi changed their tune, adding an interval to the Tiguan (only). Later still, magically an interval appears in the schedule for all the other cars.

Anyway G40 (BASF's Gylsantin equivalent to G12++), on the Zerex bottle it says 5yr/150,000 miles so I think that's the true interval. Valvoline/Zerex licenses it from BASF so I believe that recommendation comes from them. Now I'm not actually sure who develops the coolants for VAG. It could be BASF (and they are marketing under their own name as G40, etc.) or it could be someone else. But G40 is TTL774G (G12++) approved either way and so 5yrs is really the max you should have it in for IMO. With coolants, as I've learned over the years, time is typically more important than mileage (esp. since most will not hit the mileage number in 5yrs).

I have no idea if it was ever changed in my TT but when I did the timing belt I essentially changed most of the coolant. In my A3 I did it around the 5yr mark as well, as a result of upgrading the turbo. In both cases I changed it as a result of other services...I wonder if that's VAGs idea of when it should be changed? :ROFLMAO: Come to think of it, the A3 is pretty much due for it's next change this year or next 😐 Man so many maintenance items coming up!
 

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To the point on the Haldex, that's exactly correct. I had an exchange of emails with Borg Warner some time back and they were like..."Well, we suggest a fluid change and a filter change, but the OEM can make their own recommendations." Audi intentionally dropped the filters from the Maintenance Intervals right after 2006 - coincidence? :unsure:
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Discussion Starter · #17 ·
Thank you very much also TT. My eyes crossed at least twice reading your post, so I know it was thorough!

One thing I did get out of it, is that a mix of G13 and G12/+/++ is not usually the cause of the white deposit you can see in my video. It's been flushed recently - when I first got it the coolant was... just gross! I didn't picture it and am kicking myself for that now.

Also, for what it's worth: I have noticed no symptom other than this cloudiness, though my local garage said it sounded like I was driving with a piston down. I don't have the ear for that, frankly. There's a local outfit - http://www.autohausedinburgh.co.uk/ that I'll call up tomorrow to get their opinion on it as well.

Thanks again.
 

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Hang on a sec. Everywhere I’ve researched about G12 and G13 says they are miscible - dunno why manufacturers would lie
They always lie.

According to the owner's manual the coolant is factory filled with G12+ but if you look at coolant reservoir it says G12 and the factory fill coolant is color RED. Another big lie is the flow of cuurent in DC. They keep saying the current flows from the positive going to the negative. Even fluke keeps telling this big lie. It's easy to prove that current flows from negative to possitive using voltmeter. The Maf sensor is supplied by 5.5 volts from the ECU. The jumpstart terminal + and - are 12 volts. With one of the test probe connected to the maf sensor connector and the other test probe connected the jump terminal opposite polarity the voltage reading will easily tell you where current came from.[/QUOTE]
 

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Discussion Starter · #19 ·
So Autohaus don’t have availability till w/c 11/07. Will be taking her to the original garage next week sometime and have them flush it again.

It certainly looks colour wise like it’s been flushed with g12+/++ and not 13, so will need to query that as well. Maybe I should learn how too do it myself…
 

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G12+/G12++ and G13 look exactly the same. If they use tap water it will just make it worse. Impossible to flash the coolant without removing the thermostat.
 
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