Coolant reservoir empty :(

A6 All/ S6 All
#21

You can just get a generic T fitting.
https://jhmotorsports.com/jhm-oil-separator-heater-bypass-kit-for-s6-v10-5-2l-fsi.html

I don’t remember if that fits or not. But you can remove the one you have an just take it to home depot or a general hardware store. Just get a generic T fitting made from brass.

#22

Finally was able to get a breather from work for presidents day and got back to working\diagnosing the S6 coolant issue today.

  1. Had a breakthrough. So I filled the car up with gas and just let it idle for a while and also gave it some gas after a while and found another puddle right under the reservoir so the issue does seem to be reservoir related, I just assumed i had overflowed it myself however it looks like when under pressure possibly the cap is not able to keep the coolant in the reservoir and it flows into the overflow hole

    Leak7
    Leak73024×4032 1.45 MB
    .
    I am thinking it might be the cap and not the reservoir now, however I am thinking it makes sense to just replace both.

  2. The electrical connector at the bottom of the reservoir seems to be shot. I am guessing it was previously replaced but broken while replacing and i just cant seem to get it out easily. does anyone know if i can buy this part separately and just cut the wires and connect them to another connector?

Leak8
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  1. @justincredible mentioned that there is a little plastic Y connector under the reservoir but i saw no such thing, where does this Y connector attach to and what purpose does it serve? I worry whether I am missing an entire part. below shows the Hose that just connects to the bottom of the reservoir for me and there doesn’t seem to be any Y connector.

Leak9
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#23

The caps do go bad so that makes sense. If it can’t hold the pressure it’s going to go into the overflow.

The Y fitting isn’t under the tank its in line it’s coming off the tank follow the line coming off the tank to the Y you will see it.

#24

Update: got the replacement cap this friday (yesterday). tried my best to pull out the connector out of the old reservoir but nothing worked, tried a pick and hook set, the schwaben tool on ecs tuning for connectors, its just stuck. So i just put everything back and put the new cap in, and while doing so noticed the part of the cap that had fallen into the reservoir

Leak10
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Leak11
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fished those out, and connected everything. tested it out for 20 mins in the garage and then slapped everything together and took it for a longer drive. so far so good… Woot woot :D. Car is usable now and time to move on to other more maintenance like repairs.

A big shout out to @justincredible for answering all my stupid questions and also to @CountVohn, @razgriz10000 , @V10S6PA… thank you all.

Man I really took my time with this, I noticed that this thread was started on Jan 10th, almost a month a nd a half and in the end all i did was replace the reservoir cap.

I also found my whistling sounds thanks to @mixofia for starting another thread on that and it seems like for me the driver side throttle body has a small air leak. Ill post more on that thread.

Anyways thanks again guys.