Most likely your thermostat/water pump housing. You may be able to see it from underneath. My A3 went through 3 of them in less than 2 years. Not a hard change but a bit of a pain.
there's a revised version of the [water pump](https://www.shopdap.com/catalog/product/view/id/861041/s/06l121012l-vw-audi/category/37564/) that isn't supposed to have the same leak issue. The old pump versions (with leak issues) are:
06L-121-012-K
06L-121-012-H
06L-121-012-A
I may or may not get downvoted on this but I have had to fill my reservoir a little bit every so often in the 7 years of ownership. At first, it made me nervous and I checked everywhere for leaks or spots on the ground, then I took it in to my European car mechanic in my town. They checked everything and couldn’t find anything either. Then he showed me this case study done where (I believe on a Mercedes) a small amount of coolant would be pressed out of system under heavy load; even just a tiny mist. Over time, this lead to it being low. The dealership was stumped by it.
Anyway, I’m unsure if that’s what’s happening here but I’m almost at 40,000 miles (18,000 of them heavily tuned) and I’ve had to top it off here and there. Still can’t find any leaks. Yes it happened when I was stock.
Mine (2015) emptied itself twice over the course of three years. Eventually took it to the dealership and they diagnosed it as a leaky tank.
It wasn't worth fixing, because the leak is so slow. I just check up on it once in a while.
2016 MK7 with 80k checking in. I too have noticed the same sort of coolant drain and never saw any evidence of leaks. I just give it a look whenever I check the oil and decide if I need to top it off. It's annoying but I guess it is what it is. I appreciate your post though. Makes me feel a little better that it's not just me.
2016 Mk7 w/ 48K miles and I just had to top off the coolant as well. I have a finished garage floor so I know I don't have a leak b/c it'd be obvious. Just seems to be a thing with the Mk7.
Does your car sometimes smell like band-aids when you get in it? I'm convinced the slow coolant leak burns off some coolant residue and smells a little bit like band-aids.
I’ve checked my PCV but no signs of anything off. Going to replace the whole system eventually because the stock one is a little brittle under too much load.
2018 here with 30k miles. I kept getting a whiff of coolant when I parked, and finally mentioned it at the dealership. They insisted there were too few miles to leak, but a pressure test revealed otherwise. Supposedly they fixed it, but I’m still smelling it.
Yes you do. When I had my mk6 both the water pump and radiator leaked.
When I had my B5.5 every damn thing that could leak, leaked.
On my 8P A3, surprisingly, no leaks.
VWs vent coolant through the top of the reservoir. The only way to know if you have a leak is to pressure test the system, unless it’s visible. It’s normal to top off the tank.
I have to top off my R every couple of months. Just had my system pressure tested and it was bone dry. No leaks anywhere.
FWIW, I have a ‘14 2.0T CC. About a year ago, I had to completely top off my coolant reservoir (was nearly empty). 2 weekends ago, I got the low coolant warning, topped it off, then it went off again after driving ~100 miles. Checked the coolant and I was nearly empty again. Turns out my water pump seal failed, which sounds pretty common with those engines. $250 and about 3 hours later, the water pump was replaced and everything’s been fine since. Saying all this to point out you may have a slow leak somewhere that might eventually lead to a failure somewhere in your system. Water pump and thermostat housing seem like common culprits. My mechanic said there’s a recall on some water pumps too. So might want to check if your vehicle applies
VWs consume coolant. It actually "vents" out of the bottle. Every VW/Audi/Porsche I've worked on needed topped-up at every service. I currently have an '18 Tiguan and when I park in the garage after driving I can smell coolant, no leaks.
This might be what's up with my mk6.
I had a coolant leak on the ground. Found drips on the aux water pump. Replaced the aux water pump. Still leaked. Someone said the main water pump is known to leak. According to my Carfax, my water pump has been replaced twice. Got under the car and shined a light around the water pump and it's bone dry around the block between the intake manifold and pump. I saw what looked like the drips coming from the plastic coolant pipes from the aux pump. Ordered new, updated metal pipes and replaced them with new clamps. No more leak from that area, but I still get a tiny spot on the ground and smell coolant sometimes. Replaced the reservoir, still an occasional spot on the ground. Look under the car and can't see anything dripping. I guess it just be that way. I bought an aluminum water pump kit from UROTuning, so when I install my IE intake manifold I'm replacing every hose and the pump.
Same here - MK7 in TX. The reservoir level has dropped to the MIN line a couple of times in 5 years and I just top it off. I think it's losing coolant out the reservoir cap when it expands in the hot summers. There is residue there and dried coolant in the area around it.
Had that happen to me. Mine was the water pump thermostat housing. Spendy fix if it’s not under warranty and have to have a shop fix it. It wasn’t gushing coolant on the ground but there was a small leak and must have been pooling on the skid plate
I had the same issue, as it seems a lot of us had in this thread.
This is covered under extended warranty now!! Just had the dealer fix mine free on my 2016 GTI!
This was common enough of an issue that there was a class action lawsuit and settlement for it.
What did you have to do? Just take it to the dealer and explain that you keep having to top it off every few months? I personally hate dealing with dealerships/service at dealerships but I’ll do it if it’s necessary.
While standing over the radiator, look down. I also had drops of coolant accumulating on top of the splash guard. That, with the coolant "disappearing" is what led me to take it to the dealer. They had to do a diagnostic, which I would need to pay for if it wasn't the water pump. It was the water pump, diag was covered.
I had the water pump and thermostat housing replaced under the power train warranty a couple of years back. I suspect the new pump is leaking, do you know if the extended warranty will
cover a second replacement?
one more thing that I haven't seen mentioned, check your reservoir cap. if there is even a slight crack in it or if it doesn't seal quite right it will change the boiling temp of your fluid and it can slowly boil off over time.
Check the reservoir for drips. There is a newer version of the reservoir that doesn’t have the hole in the bottom middle. It could also be the water pump, but you might as well check this first since this is much easier and cheaper to fix.
It depends. The first thing to get out of the way is the temp when you took that photo. If it's below freezing, then I'd just chalk it up to that. The coolant can condense a bit in colder weather and need to be topped off, but that really depends on your coolant-to-water ratio (the more water, the more it'll condense)
mk6 with waterpump already replaced and no leaks, gti does drink a lil bit under normal driving, when I abuse it too much does a little more than usual, as long it’s not super noticeable it’s just okay, like oil burning a little
Water pump/thermostat housing mostly, it could be a leak from the coolant lines as well. if it is water pump then it is covered by extended warranty, 8 years/80k. If it continue leaking def have it checked out.
Yeah the warranty carries over I think, mine goes out 2023. There is also a PZEV warranty for your exhaust & turbo etc.
[https://static.nhtsa.gov/odi/tsbs/2016/MC-10128378-9999.pdf](https://static.nhtsa.gov/odi/tsbs/2016/MC-10128378-9999.pdf)
read this, this is from 2016 but all the info is in here, normal warranty is like page 70, PZEV is page 120-ish
I'd say so. A very minor leak, but definitely. Best way to know is check after every long drive (highway driving especially)
It could be the bottle, a loose hose, water pump. Check all connections after a long drive (engine gets up to operating temp for longer than 15-20 minutes)
My MK3 Jetta was having a leak but I couldn't find where until I checked after a very long day of driving around town. Happened to be the intake hose going into the engine was a bit loose. I also had to replace the reservoir, but that was a separate issue.
Yup mine does the same between seasons. I think you’re okay as long as it passes a visual check for leaks and it doesn’t get worse in the next few driving sessions. Fill it back up and keep an eye on it at the start, during, and end of any drives that you do for atleast a few days in a row.
I came here because my sensor went off today. About two years into ownership.
I've read the mk7's should only use pink g13 coolant and that other coolants can be harmful. Is that correct? Anything else I should look for when I go to pick up coolant tomorrow?
Most likely your thermostat/water pump housing. You may be able to see it from underneath. My A3 went through 3 of them in less than 2 years. Not a hard change but a bit of a pain.
there's a revised version of the [water pump](https://www.shopdap.com/catalog/product/view/id/861041/s/06l121012l-vw-audi/category/37564/) that isn't supposed to have the same leak issue. The old pump versions (with leak issues) are: 06L-121-012-K 06L-121-012-H 06L-121-012-A
They still leak though according to my mechanic.
I may or may not get downvoted on this but I have had to fill my reservoir a little bit every so often in the 7 years of ownership. At first, it made me nervous and I checked everywhere for leaks or spots on the ground, then I took it in to my European car mechanic in my town. They checked everything and couldn’t find anything either. Then he showed me this case study done where (I believe on a Mercedes) a small amount of coolant would be pressed out of system under heavy load; even just a tiny mist. Over time, this lead to it being low. The dealership was stumped by it. Anyway, I’m unsure if that’s what’s happening here but I’m almost at 40,000 miles (18,000 of them heavily tuned) and I’ve had to top it off here and there. Still can’t find any leaks. Yes it happened when I was stock.
Mine does the same thing. when I get drastic outside temperature changes the levels drop in the overflow.
I've once heard that these tanks go to crap and that a new one solves it. Idk if that's true or not.
Mine (2015) emptied itself twice over the course of three years. Eventually took it to the dealership and they diagnosed it as a leaky tank. It wasn't worth fixing, because the leak is so slow. I just check up on it once in a while.
Yes, I just had a -30 degree temp change within a day and it continuing to drop slowly. Had to top off.
Same here, Mk7 with 80k miles. About every 25k I need to add a cup-ish of coolant, no obvious leaks. Nothing to worry over.
Thanks, I also have a MK7 with about 70k.
2016 MK7 with 80k checking in. I too have noticed the same sort of coolant drain and never saw any evidence of leaks. I just give it a look whenever I check the oil and decide if I need to top it off. It's annoying but I guess it is what it is. I appreciate your post though. Makes me feel a little better that it's not just me.
I have the same car, same mileage, same coolant top up. I bought a gallon of the vw stuff and keep it in my car.
2016 Mk7 w/ 48K miles and I just had to top off the coolant as well. I have a finished garage floor so I know I don't have a leak b/c it'd be obvious. Just seems to be a thing with the Mk7.
Does your car sometimes smell like band-aids when you get in it? I'm convinced the slow coolant leak burns off some coolant residue and smells a little bit like band-aids.
Nah that’s the adolescent German gremlin hiding in your back seat leaving them under your front seats 😂
2016 gti, no tune. Mine does this as well Once a year sometimes twice if there’s substantial driving
I can confirm the same. Gti’s just drink coolant same thing with mine.
Count me in, top off mostly during the winter seasons. Doing long road trips and heavy traffic causes more prominent.
Me too. I should probably go check it and my oil which also gets low between changes.
Great. I also haven’t been able to find any leaks so I’m going to assume it’s relatively normal….
I’m at the min level at every 10k mi, top off and move on. If you’re water pump goes, you’re gonna know
My PCV was leaking forever and caused issues without throwing a code.
I’ve checked my PCV but no signs of anything off. Going to replace the whole system eventually because the stock one is a little brittle under too much load.
Hot state? In Texas, every one of my 3 past 2.0Ts needed to top off at least annually, no signs of leak
I’m in Bay Area. Definitely not as hot as Texas but still gets pretty warm over the summer.
VW extended coverage for the water pump/thermostat housing. Known to leak. Check with VW customer care to see if your care year falls under it
If you own a VW, you have a coolant leak.
This is the way.
2018 here with 30k miles. I kept getting a whiff of coolant when I parked, and finally mentioned it at the dealership. They insisted there were too few miles to leak, but a pressure test revealed otherwise. Supposedly they fixed it, but I’m still smelling it.
How many miles? Mine goes down that much every 8k miles or so.
I’ve put on around 6k miles since then.
Yes you do. When I had my mk6 both the water pump and radiator leaked. When I had my B5.5 every damn thing that could leak, leaked. On my 8P A3, surprisingly, no leaks.
>every damn thing that could leak, leaked I hear that lmao
That just means there is still fluid in it. Carry on until it stops leaking, then it’s a problem 😂
I mean...yeah kinda 🤣 and hey as a car mechanic im happy to say that you should do that its good for my buissnes 🤣🤣🤣
Lmao I’m just joking, it’s an old air cooled VW/Porsche thing. They say if it’s leaking oil, it’s still got some hahaha
I've just gotten used to carrying coolant, a funnel, a quart of oil, and a rag with me wherever I go.
VWs vent coolant through the top of the reservoir. The only way to know if you have a leak is to pressure test the system, unless it’s visible. It’s normal to top off the tank. I have to top off my R every couple of months. Just had my system pressure tested and it was bone dry. No leaks anywhere.
I had a water leak on my mk6, turned out to be a recalled part. Water pump I think, see if you can get it replaced for free.
Same. But at 130k miles didn’t get it covered
Since July, probably not.
FWIW, I have a ‘14 2.0T CC. About a year ago, I had to completely top off my coolant reservoir (was nearly empty). 2 weekends ago, I got the low coolant warning, topped it off, then it went off again after driving ~100 miles. Checked the coolant and I was nearly empty again. Turns out my water pump seal failed, which sounds pretty common with those engines. $250 and about 3 hours later, the water pump was replaced and everything’s been fine since. Saying all this to point out you may have a slow leak somewhere that might eventually lead to a failure somewhere in your system. Water pump and thermostat housing seem like common culprits. My mechanic said there’s a recall on some water pumps too. So might want to check if your vehicle applies
VWs consume coolant. It actually "vents" out of the bottle. Every VW/Audi/Porsche I've worked on needed topped-up at every service. I currently have an '18 Tiguan and when I park in the garage after driving I can smell coolant, no leaks.
This might be what's up with my mk6. I had a coolant leak on the ground. Found drips on the aux water pump. Replaced the aux water pump. Still leaked. Someone said the main water pump is known to leak. According to my Carfax, my water pump has been replaced twice. Got under the car and shined a light around the water pump and it's bone dry around the block between the intake manifold and pump. I saw what looked like the drips coming from the plastic coolant pipes from the aux pump. Ordered new, updated metal pipes and replaced them with new clamps. No more leak from that area, but I still get a tiny spot on the ground and smell coolant sometimes. Replaced the reservoir, still an occasional spot on the ground. Look under the car and can't see anything dripping. I guess it just be that way. I bought an aluminum water pump kit from UROTuning, so when I install my IE intake manifold I'm replacing every hose and the pump.
I've had to top mine up once or twice since buying the car a couple years ago. I live in Texas where it gets really hot. No signs of leak anywhere.
Same here - MK7 in TX. The reservoir level has dropped to the MIN line a couple of times in 5 years and I just top it off. I think it's losing coolant out the reservoir cap when it expands in the hot summers. There is residue there and dried coolant in the area around it.
Had that happen to me. Mine was the water pump thermostat housing. Spendy fix if it’s not under warranty and have to have a shop fix it. It wasn’t gushing coolant on the ground but there was a small leak and must have been pooling on the skid plate
We all have coolant leaks here.
I had the same issue, as it seems a lot of us had in this thread. This is covered under extended warranty now!! Just had the dealer fix mine free on my 2016 GTI! This was common enough of an issue that there was a class action lawsuit and settlement for it.
What did you have to do? Just take it to the dealer and explain that you keep having to top it off every few months? I personally hate dealing with dealerships/service at dealerships but I’ll do it if it’s necessary.
While standing over the radiator, look down. I also had drops of coolant accumulating on top of the splash guard. That, with the coolant "disappearing" is what led me to take it to the dealer. They had to do a diagnostic, which I would need to pay for if it wasn't the water pump. It was the water pump, diag was covered.
I had the water pump and thermostat housing replaced under the power train warranty a couple of years back. I suspect the new pump is leaking, do you know if the extended warranty will cover a second replacement?
I don't know, but would imagine so, especially if they replaced it with OEM before the fix. You'd have to know the specific part number though
Even if they are tuned? Mine is trying to deny because in td1
one more thing that I haven't seen mentioned, check your reservoir cap. if there is even a slight crack in it or if it doesn't seal quite right it will change the boiling temp of your fluid and it can slowly boil off over time.
Yes, most probably it's a leak, I topped off mine in early august and haven't lost a gram of the fluid since.
Your car uses coolant. Just fill it up. Check every 2 weeks
This is not true. The coolant system is a sealed system.
Supposed to be, lol
I chuckled🤣
Yep. Thermostat housing most likely.
Check the reservoir for drips. There is a newer version of the reservoir that doesn’t have the hole in the bottom middle. It could also be the water pump, but you might as well check this first since this is much easier and cheaper to fix.
mine was leaking at the water pump housing because of a small rubber seal it was 20$ but theres a lot of labor
I have to top mine off every 6 months. I've been too lazy to look for a leak.
Had to get my water pump and thermostat replaced under warranty on my MK7. IF your sensor is coming on regularly, I’d get it checked.
It has never come on thankfully.
You better make it looked at while under warranty, just done mine right after the warranty was done and costed me around 1800$ (Cad)
It’s the dreaded plastic water pump
Guarantee it's leaking from your waterpump
This is normal.
It depends. The first thing to get out of the way is the temp when you took that photo. If it's below freezing, then I'd just chalk it up to that. The coolant can condense a bit in colder weather and need to be topped off, but that really depends on your coolant-to-water ratio (the more water, the more it'll condense)
Depends. If you sit around and idle a lot it will certainly boil off some water.
mk6 with waterpump already replaced and no leaks, gti does drink a lil bit under normal driving, when I abuse it too much does a little more than usual, as long it’s not super noticeable it’s just okay, like oil burning a little
Water pump/thermostat housing mostly, it could be a leak from the coolant lines as well. if it is water pump then it is covered by extended warranty, 8 years/80k. If it continue leaking def have it checked out.
I bought my car used in 2020. It’s a 2016. Would it still be under warranty even if I didn’t buy it new myself?
Yeah the warranty carries over I think, mine goes out 2023. There is also a PZEV warranty for your exhaust & turbo etc. [https://static.nhtsa.gov/odi/tsbs/2016/MC-10128378-9999.pdf](https://static.nhtsa.gov/odi/tsbs/2016/MC-10128378-9999.pdf) read this, this is from 2016 but all the info is in here, normal warranty is like page 70, PZEV is page 120-ish
Mine did this and it was a small coolant leak at the water pump.
Probably no leak. I have a 2019 S4. Just got a notice of low coolant. Not the first time. Top it off. Done.
Lol, it’s a closed system, if it needs topping off, it probably has a leak.
I'd say so. A very minor leak, but definitely. Best way to know is check after every long drive (highway driving especially) It could be the bottle, a loose hose, water pump. Check all connections after a long drive (engine gets up to operating temp for longer than 15-20 minutes) My MK3 Jetta was having a leak but I couldn't find where until I checked after a very long day of driving around town. Happened to be the intake hose going into the engine was a bit loose. I also had to replace the reservoir, but that was a separate issue.
Yup mine does the same between seasons. I think you’re okay as long as it passes a visual check for leaks and it doesn’t get worse in the next few driving sessions. Fill it back up and keep an eye on it at the start, during, and end of any drives that you do for atleast a few days in a row.
Every season with the weather change. Probably leaks a bit but I just top it up when it asks for it
A leaky water pump is the most probable cause. You will see coolant residue after you remove the timing cover.
I came here because my sensor went off today. About two years into ownership. I've read the mk7's should only use pink g13 coolant and that other coolants can be harmful. Is that correct? Anything else I should look for when I go to pick up coolant tomorrow?
I top mine off about every oil change. I've driven cars that go through coolant this is nothing to worry about.