16 Audi S3 G13 Coolant - 40,500 miles

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Below is Polaris Coolant Analysis on my 2016 Audi S3 with 40,500 miles. Coolant has not been changed and serviced by the dealer regularly. I think a service or so ago they topped off the coolant with concentrate thus the higher than 50/50 concentration. I sucked out all the coolant in the expansion tank and filled with new 50/50 and will do this every 500-1000 miles and see how it is after few thousand miles. I cant find a good G13 virgin analysis and thus do not know how the other perimeters look like. Not too worried and will dump the fluid at 75k unless someone thinks it should be done now. [Linked Image from photos.smugmug.com]
 
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I think you're fine and this (as you know) is a long life coolant...I believe Audi says it's good for the life of the vehicle...I wouldn't go THAT far, but a 75,000 mile change should be more than good enough for this coolant.
 

FCD

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Interesting that there are Phosphates present, G13 isn't supposed to have any, just Silicate + OAT The new G12 Evo ( TL-774-L ) that was introduced in 2019 does however add Phosphates to the Silicate and OAT.
 
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I don't fall for the "lifetime" nonsense. The heater core on our 2014 Jetta plugged up with only 54,000 miles. This is common on VAG products. Likely will change every 30K moving forward.
 

agpatel

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Originally Posted by FordCapriDriver
Interesting that there are Phosphates present, G13 isn't supposed to have any, just Silicate + OAT The new G12 Evo ( TL-774-L ) that was introduced in 2019 does however add Phosphates to the Silicate and OAT.
I am wondering if the dealer topped it off with G12+ but I would assume that they would not have any left as G12++ is the last verson before G13 and its the same essentially. Did not see any build up on the sensor in the tank and the silicate packet is still in tact - primary reason for me draining the tank was to check on the packet in the expansion tank.
 
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Originally Posted by agpatel
Originally Posted by FordCapriDriver
Interesting that there are Phosphates present, G13 isn't supposed to have any, just Silicate + OAT The new G12 Evo ( TL-774-L ) that was introduced in 2019 does however add Phosphates to the Silicate and OAT.
I am wondering if the dealer topped it off with G12+ but I would assume that they would not have any left as G12++ is the last verson before G13 and its the same essentially. Did not see any build up on the sensor in the tank and the silicate packet is still in tact - primary reason for me draining the tank was to check on the packet in the expansion tank.
What is a "silicate packet"?
 

agpatel

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VW/Audi in the newer cars have a packet Of silica in the expansion tank to supplement the coolant as the silica is used up. The silica is to protect against aluminum corrosion.
 
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Originally Posted by agpatel
VW/Audi in the newer cars have a packet Of silica in the expansion tank to supplement the coolant as the silica is used up. The silica is to protect against aluminum corrosion.
thumbsup learned something new.
 

FCD

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Originally Posted by agpatel
VW/Audi in the newer cars have a packet Of silica in the expansion tank to supplement the coolant as the silica is used up. The silica is to protect against aluminum corrosion.
Interesting, as VW coolant from 2012 onwards already has Silicate + OAT The newest, called G12 Neo, is the same as G13 but has Phosphate aswell
 
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Originally Posted by gregk24
I don't fall for the "lifetime" nonsense. The heater core on our 2014 Jetta plugged up with only 54,000 miles. This is common on VAG products. Likely will change every 30K moving forward.
Never had a VW with the heater core plugged up at 54,000 miles... 2002 Golf TDI at 170,000 miles... no issues. Coolant was replaced at 100,000 miles with the timing belt change 2008 Passat, traded in at 217,000 miles. Coolant was replaced at 100,000 miles with timing belt change 2016 Tiguan, up to the new engine at 107,000 miles... no issues... new engine came with new coolant.
 
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Heater Core failure common on 2012 to 2014 Passats. I have a 2014 TDI Passat that had to have a new heater core at 27,000 miles. Buddy has same car and had his replaced at about the same mileage. I've been monitoring the PH of the coolant and mine at 32,000 miles was already at 6.5. I changed about 3 liters of the coolant (G13) and the PH has come back up Pretty close to what the new coolant is. VW has extended warranty on the Passat to 120,000 miles. I don't think this heater core issue is just with the TDI cars.
 

FCD

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It's probably why they have added now Phosphate to the formulation with the new G12 Evo, G13 had a fairly low Reserve Alkalinity of only about 5 and a starting pH of about 8 which ofcourse means more likelyhood of it going acidic.
 
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VW has had many issues with heater core pluggage going back a couple decades. The cores themselves are very narrow and thin and they stack the rows pretty tight for efficiency. This is a double edged sword as they transfer heat fantastically but are prone to plugging off. You usually here about it with the tdi's but it happens to the gassers too. Back flushing the core at the firewall will usually get you by for another year or two. Many models are extremely easy to change from the drivers footwell. Others are a dash out nightmare.
 
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audi heater core.jpg

VAG heater cores have a "spiral insert" to slow the coolant flow for better heat transfer..a nice idea. The problem is iron blocks and coolant with poor anti-corrosion additives. This heater core had the original VW coolant. Not lifetime rust resistance for sure. The small rust partials get trapped in the tubes.
 
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