Coolant loss C7 A7

[SlickMachine]

I officially have this problem. 2012 A7, APR Stage 2, 60k miles.
About 4000 miles ago I noticed my expansion tank was below the MIN mark, so I added some G40 and brought it up to the mid level. 1000 miles later, had to add a bit more to maintain that level. Here I am 4000 miles later and today I just added more to maintain the mid level between min and max. To date I've added about 1.5l of Coolant over 4000 miles. All evaluations of coolant have been done after car sits overnight by the way.
S4 guys have this problem I see. Mostly looks like this problem is due to pcv failure and coolant moving into oil supply. Only other culprit I can find is intercooler inside the blower leaking. Anyone else here have this issue? Tips on figuring this out? I do oil changes with an extractor, I'm not sure I would be able to see coolant in the oil if that were the problem given how watery 0w40 is to begin with.
Pcv fix requires blower removal and more to get at the plastic POS part located in the hottest section of the engine (thanks Audi you German asshats). $1500ish is what I gather for an Indy shop. There are zero leaks on the garage floor.. so I'm pretty confident it's not something as easy as a hose or fitting, unless it's just being contained on the top side of the under body shield.
#FML.

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[Mr_Nachi]

let me know if you find the culprit.... ive removed blower and damn near replaced everything... i replaced the crankcase vent valve, o-ring in the water pipe, the actual water pipe its self and every gasket in there all from Audi OEM (oddly enough most of the parts made in italy hmm)... no more coolant smell or coolant low warning... but i do notice it goes down every so often i just replenish... speaking of its been a few weeks i should check to see if its still getting low... but def let me know if you find the culprit.. good luck MAte

[SlickMachine]

let me know if you find the culprit.... ive removed blower and damn near replaced everything... i replaced the crankcase vent valve, o-ring in the water pipe, the actual water pipe its self and every gasket in there all from Audi OEM (oddly enough most of the parts made in italy hmm)... no more coolant smell or coolant low warning... but i do notice it goes down every so often i just replenish... speaking of its been a few weeks i should check to see if its still getting low... but def let me know if you find the culprit.. good luck MAte

I will.
Did you get the coolant smell after driving and then could smell it coming from under the hood? I notice that too if that's the case.
I'm strongly considering unloading the car at this point. I've got front end clunks, wheel bearings about to go and now this.

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[RAF_S7]

Coolant really only has four places to go.

1. External leak - evidence on the ground (don’t confuse with a/c condensation drain)

2. Internal leak #1 - into your oil supply. You should check for “mayonnaise” type deposits under your oil cap.

3. Internal leak #2 - into your combustion chamber, mixing with fuel, normally accompanied by loss of performance, or white smoke from the exhaust.

4. Coolant leak on the turbo chargers (o-ring failures). You can spot this by looking at the top of the turbo units, where the coolant pipes enter the turbo. You can see the “crusty” residue of coolant around the pipes. This is subject to a TSB (you can search the forum)

All of the above will result in coolant being used at a higher rate than normal.

[Mr_Nachi]

im gona have to check in on the oil on the next oil change next week... i hate how we cant check oil on a dipstick

[yeuchau]

did you take it to shop for pressure test yet?

[Mr_Nachi]

I will.
Did you get the coolant smell after driving and then could smell it coming from under the hood? I notice that too if that's the case.
I'm strongly considering unloading the car at this point. I've got front end clunks, wheel bearings about to go and now this.

Sent from my SM-G965U using Audizine mobile app

i initially did.. before replacing the vent valve.. the hose from the thermostat and all the o-rings and seals... now no smell... just every few weeks its low..