Engine Coolant - a new one…

[pwdrskr]

So, got a warning that the engine coolant is low. Easy, right? Not so fast, buster. Nothing is easy with this car. Popped the hood and am immediately stumped. Where is the coolant cap? Oh well, off to read the manual where I find out that the engine coolant is different from any other car I’ve owned. Anyway, the reservoir is up near window on the passenger side. Open the cap to find the level is so low it is not only below the “Low” level, it isn’t even visible!

Reading further into the manual, there is a warning jot to add coolant if there isn’t Any viable in the reservoir. I’m, OK. Now what? Apparently when this happens one shouldn’t add fluid as this may cause air to become trapped in the coolant system. Well BLEEP! This now means I have to they and get the car into Audi service. For coolant! BTW, they are so busy, appoints are a month out!

Anyone have a different opinion on this? Can coolant be added by the simpleton owner of an RS5?

BTW, the coolant is of course a special mix of concentrate and, per the manual, ideally distilled water.

Wow! I know these are complex cars, but this is unexpected.

Not to mention, why is a two year old car devoid of engine coolant? A leak? Did all boil over while we drove nowhere over the past two year thanks to covid? What am I missing?

[ywang98]

My 2018 S4 before my current RS5 would somehow "use up" coolant (but no leak). I suspected was the cap leaking (letting evaporation) a small amount or the water pump just leaking a very small amount. I have to add a little bit periodically. But I just add straight coolant (G13) since it's just a little bit at a time. My RS5 seems to be holding coolant better but still goes down a bit after a period of time. My wife's SQ7 seems to be the same too. And for a larger amount of coolant, I would use only distilled water/coolant 50/50 mix. I don't wait until I can't see coolant in the reservoir though.

I am going to check my coolant right now.

My VW R32 also "drank" coolant as well, a very small amount.

Ok, both my RS5 and my wife's SQ7 are right at the min line. Time to add more.

[pwdrskr]

My 2018 S4 before my current RS5 would somehow "use up" coolant (but no leak). I suspected was the cap leaking (letting evaporation) a small amount or the water pump just leaking a very small amount. I have to add a little bit periodically. But I just add straight coolant (G13) since it's just a little bit at a time. My RS5 seems to be holding coolant better but still goes down a bit after a period of time. My wife's SQ7 seems to be the same too. And for a larger amount of coolant, I would use only distilled water/coolant 50/50 mix. I don't wait until I can't see coolant in the reservoir though.

I am going to check my coolant right now.

My VW R32 also "drank" coolant as well, a very small amount.

Ok, both my RS5 and my wife's SQ7 are right at the min line. Time to add more.

Thanks for the info. It’s another data point. It never would have occurred to me to need to check coolant on a two year old car with only -12k miles on the odometer. By contrast, I never checked nor had to put coolant in our former a4 allroad once during the entire eight years ownership.

[pwdrskr]

BTW, anyone have a suggestion for a good brand of G12++ or G13 coolant?

[pwdrskr]

Here’s another stupid question, where exactly are the markings to be read to determine the coolant level? The manual is nearly useless! Looking in the reservoir, the upper indicator inside the neck of the reservoir is labeled “min” and and the lower marking on the exterior is marked “max”. This seems backwards. How can the max level be below the min level indicator on a single reservoir?

[ywang98]

I go to a VW dealership (or Audi) to buy the G13, but there are other brands. I just feel better using VWAG G13 since that is exactly what it is called for.

I am not sure where you are looking at the reservoir for the markings, but I see my RS5's reservoir markings toward the front of the car. The trick is to shine a flashlight into the reservoir to see the coolant level as coolant is still pretty clean and the faint pink color is hard to see without shining a light at the top of the reservoir (put the flashlight butt against the top). The min line is easy to see, but the max line is pretty close to the seam of the top and the bottom of the reservoir. It is hard to see if you don't get close.

So I saw your post in the other forum. The line inside the fill neck is for the float to point at, once you have coolant inside the reservoir. You coolant is way down, so the float is down there. I always look at the outside mark lines for min and max.

[pwdrskr]

I got to a VW dealership (or Audi) to buy the G13, but there are other brands. I just feel better using VWAG G13 since that is exactly what it is called for.

I am not sure where you are looking at the reservoir for the markings, but I see my RS5's reservoir markings toward the front of the car. The trick is to shine a flashlight into the reservoir to see the coolant level as coolant is still pretty clean and the faint pink color is hard to see without shining a light at the top of the reservoir (put the flashlight butt against the top). The min line is easy to see, but the max line is pretty close to the seam of the top and the bottom of the reservoir. It is hard to see if you don't get close.

So I saw your post in the other forum. The line inside the fill neck is for the float to point at, once you have coolant inside the reservoir. You coolant is way down, so the float is down there. I always look at the outside mark lines for min and max.

Hmm, so I did shine a flashlight and just don’t see anything that could be remotely similar to what is in the manual.

Than “max” line I do see is on the exterior, lower passenger side of the reservoir. It is not easy to see because the view is blocked. Again, it doesn’t look anything like what is described in the manual.

You are correct, the float is way down inside the neck of the reservoir. Maybe I can’t see the markings because the reservoir is bone dry.

Is the manual correct, that in this condition I shouldn’t fill it myself or risk trapping air in the system?

This whole thing irritates me…

[ywang98]

Yes, the max line at the outside is right below the reservoir edge (top and bottom halves). I guess that is why they put a float inside the reservoir.

I've never run so dry in the reservoir in any of my cars, but the manual is correct that if you just pour coolant in, air might be trapped in the lines below. I would use a syringe to slowly put a bit of coolant at a time to slowly fill up the hoses below the reservoir. A few drops at a time probably should not trap air in the lines. Do this until you can start to see coolant come up to the reservoir level, then pour the coolant in.

But this is only a patch. You should most likely get a flush from the service department to avoid any air bubbles in the system.

I actually have a vacuum flushing device that I bought years ago from ECS, but I've never used it. They show this on Youtube, and it is really cool how it sucks all the air out and then coolant gets sucked in.

[ywang98]

https://youtu.be/Y2CAr2pOva8
This is what I have.

https://www.ecstuning.com/b-schwaben...vacuation_tool

[JohnEnglish]

You can buy a gallon of OEM G13 premixed coolant from the dealer. I bought a quart of OEM G13 premix from ECS.

https://www.ecstuning.com/b-genuine-...ant/ga13774m2/

[pwdrskr]

Yes, the max line at the outside is right below the reservoir edge (top and bottom halves). I guess that is why they put a float inside the reservoir.

I guess I should have done a better job of describing where the "max" line is located. It isn't anywhere near the top of the reservoir. It is located essentially out of sight 8-10 inches below the cap on the outside, passenger side of the reservoir body. Again, it makes zero sense that the "max" line is below the "min" line. Nor does it makes sense that the "max" line is on the outside of the reservoir and the "min" line is on the inside. None of which looks anything like what is written in the owner's manual.

I can't determine if there is any coolant in the reservoir at all. I can look down into the reservoir with the cap off and don't see any coolant. However, the mesh filter in the neck of the opening prevents viewing to the bottom of the interior of the reservoir.

All of this is just ridiculous. It should not be this difficult just to determine fluid level. Its almost like it was designed to be confusing on purpose. It makes me angry.

I do appreciate all those who've tried to help out...

https://youtu.be/Y2CAr2pOva8
This is what I have.

https://www.ecstuning.com/b-schwaben...vacuation_tool

Thanks, watched the video. How important is it to drain the system? The video doesn't show how that is done (I'm sure because every car is different). In my case however, the car may already be devoid of coolant...well, not really. I've driven the car and the engine temp never goes above normal, so there must be enough coolant still in the system to do something.

Wonder if this one on Amazon is equivalent to the Schwaben one...

You can buy a gallon of OEM G13 premixed coolant from the dealer. I bought a quart of OEM G13 premix from ECS.

https://www.ecstuning.com/b-genuine-...ant/ga13774m2/

Thank you, John. You are always good for helpful suggestions!

ECS also sells a 5 Liter volume version, which happens to be in stock and available to ship immediately. The lower volume one is several days out according the ECS product page.

Apologies if any of the above is incoherent. Its very late, or early, here and I'm not all there...less sold than usual.

[Bezlar]

Lol. This making me go look now.


Sent from my iPhone using Tapatalk

[JohnEnglish]

I guess I should have done a better job of describing where the "max" line is located. It isn't anywhere near the top of the reservoir. It is located essentially out of sight 8-10 inches below the cap on the outside, passenger side of the reservoir body. Again, it makes zero sense that the "max" line is below the "min" line. Nor does it makes sense that the "max" line is on the outside of the reservoir and the "min" line is on the inside. None of which looks anything like what is written in the owner's manual.

Is your RS5 a 2019? Apparently the 2018 and 2019 manuals only had the instructions for the 4 cylinder reservoir. The 2020+ manuals corrected this. For the V6, the MAX line is apparently indeed the top of the reservoir

Here’s a screen shot from a 2020 manual mentioning that for V6 engines the coolant MAX line is the top of the reservoir.

D694D762-6312-4B77-9AC4-C40BBB58337D.jpg

[Burrcold]

Is your RS5 a 2019? Apparently the 2018 and 2019 manuals only had the instructions for the 4 cylinder reservoir. The 2020+ manuals corrected this. For the V6, the MAX line is apparently indeed the top of the reservoir

Here’s a screen shot from a 2020 manual mentioning that for V6 engines the coolant MAX line is the top of the reservoir.

D694D762-6312-4B77-9AC4-C40BBB58337D.jpg

That was my understanding as well and what I replied on AW. There's an overflow surrounding the top of the reservoir so it only makes sense for the very top to be the max.

[coolwater]

Does you dealer not just top you off right in the drive bay? I’ve had oil and coolant topped off without waiting for an actual appointment and at no cost.

-cW


Sent from my iPhone using Tapatalk

[JohnEnglish]

Does you dealer not just top you off right in the drive bay? I’ve had oil and coolant topped off without waiting for an actual appointment and at no cost.

-cW

I’ve never had this happen at any dealer regardless of the brand of car. I have had a couple of dealers tell me they can only perform service or inspections in the service area due to their insurance policy.

[coolwater]

I’ve never had this happen at any dealer regardless of the brand of car. I have had a couple of dealers tell me they can only perform service or inspections in the service area due to their insurance policy.

I can see the insurance being an issue. Still even just low oil or coolant you shouldn’t need an appointment. I just call my SA and they just ask me to stop by and they just take care of it while I wait. They did that for low oil on RS5 and noisy Wiper Blades on my SQ5. Low coolant on S3. Maybe because I have audicare on both cars…

-cW


Sent from my iPhone using Tapatalk

[JohnEnglish]

I’ve had Audi Care on all my Audis and the dealers won’t do anything without an appointment. ¯\_(ツ)_/¯

I'm guessing it's because they are all always very busy.

[pwdrskr]

Is your RS5 a 2019? Apparently the 2018 and 2019 manuals only had the instructions for the 4 cylinder reservoir. The 2020+ manuals corrected this. For the V6, the MAX line is apparently indeed the top of the reservoir

Here’s a screen shot from a 2020 manual mentioning that for V6 engines the coolant MAX line is the top of the reservoir.

D694D762-6312-4B77-9AC4-C40BBB58337D.jpg

Thanks, this now makes a little more sense. Still makes me wonder about the "max" marking lower on the reservoir.

Does you dealer not just top you off right in the drive bay? I’ve had oil and coolant topped off without waiting for an actual appointment and at no cost.

-cW

I'll be finding that out sometime today. Sure would hate to need a scheduled appointment to get this sorted. The dealership online Service scheduler shows the next appointment in APRIL! Can't be without the car for over a month! If that turns out to be the only option, I'll try and do it myself. Ordered the extractor and some G13 fluid. We'll see what happens first.

[dal59]

Last night I was reading all of this, and thought I had better check in the morning. The markings are a bit confusing and somewhat difficult to see. The only one I found easy to spot is the big "MAX" indicator at the bottom, on the exterior that faces the passenger side. I suppose if this thread had not been started, I would have just assumed that would be the proper place to check in conjunction with what the float was doing.

Anyway, I checked this morning, and I am at the MAX line and the float bounces all the way to the top as soon as the cap is removed. Only after checking did I remember that I was just in for my 10k mile service a couple of months ago. Oh well, better safe than sorry.

Unrelated (sort of). While out there I thought I would check my tire pressures. When I first read, they recommend checking them every month, I thought that was ridiculous. However, since owning this thing and realizing how a slight difference in air pressure can change the ride quality, I now check it monthly. Anyway, while out there I also checked my wife's BMW and see she has Nitrogen in her tires. Now, I can't even use regular air anymore. Is there no end to the "special" requirements?

[JohnEnglish]

Anyway, while out there I also checked my wife's BMW and see she has Nitrogen in her tires. Now, I can't even use regular air anymore. Is there no end to the "special" requirements?

Nitrogen filled tires is a cash grab. The air we breathe is almost 80% nitrogen. Just fill her tires with air from a compressor.

[Bezlar]

Nitrogen filled tires is a cash grab. The air we breathe is almost 80% nitrogen. Just fill her tires with air from a compressor.

True story.


Sent from my iPhone using Tapatalk

[dal59]

Awesome! I can now cross off one thing from the "special" list.
tks, dal

[aybyman]

What coolant are we supposed to use in our cars? I have an A5 manual that came with my RS5 and it says G12...but it seems I've heard some people using G13?

[JohnEnglish]

G12, G12+, and G12++ have all been superseded by G13. If your car came with G12, G12+, or G12++ coolant, you can use G13 to top it off.

[AnewMadrid]

I had this come on and put some coolant in but the warning ⚠️ is still on. Anyway to clear the warning from within the car w/o a diagnostic tool?

[Smac770]

If the coolant level warning is still on, you might have an issue with the sensor device or the wiring from it back to the control module.

[AnewMadrid]

Thanks. Yeah it's still on. Sucks I hardly drive this car and probably put on 600 miles since Jan. Audi San Jose does free top off maybe just go there.

[AnewMadrid]

If the coolant level warning is still on, you might have an issue with the sensor device or the wiring from it back to the control module.

You nailed it. 1300 bucks to get the wiring done.

[Smac770]

Damn, but if you got the coin to burn I guess. Two new wires, some crimp terminals, an hour time. Wonder if your harness had more issues than just that those two wires. The sensor itself is integrated into the coolant tank, which is only $120-$150, but would have required coolant draining/filling if they had to replace it.

[AnewMadrid]

Damn, but if you got the coin to burn I guess. Two new wires, some crimp terminals, an hour time. Wonder if your harness had more issues than just that those two wires. The sensor itself is integrated into the coolant tank, which is only $120-$150, but would have required coolant draining/filling if they had to replace it.

Well that didn't work. The coolant light came back on andnIve literally driven no more than ten miles. Need to take it back this morning.

[ywang98]

Dal, I check my pressure every week. Just an OCD thing. And I check my onboard pressure readout every time I drive. Another OCD thing.

[ywang98]

I checked the coolant level today for the RS5 and the SQ7. It's been a couple of months at least since I last checked. The level was down, just a bit. So, this has been my experience with VWAG cars so far (and I've had over 10 VW's prior).

[c99]

G12, G12+, and G12++ have all been superseded by G13. If your car came with G12, G12+, or G12++ coolant, you can use G13 to top it off.

Truth but G13 was superseded by G12 Evo. All Audi cars m.y. 2019 and newer are fullfild with G12 Evo.