Audi A3 8V Slow Coolant Leak?

[emoore99]

Hi all,

Picked up a 2014 Audi A3 1.6TDI a few months ago.

Noticed that every 3-4 weeks or so the coolant light will go on and I have to top it up.

Been looking for puddles of coolant, can't ever see any.

The heater in the car is also very temperamental and doesn't work very well. When it does it will blow hot air for about 10 seconds then become lukewarm.

I have checked the carpets near the heater core and nothing damp to suggest leakage.

Apart from that the car runs fantastic and is very smooth so one of those annoying things.

Any ideas?

[rowlands57]

Likely the water pump. You need to get the belly pan off and look up from below to see if it's leaking. If it is the bottom front of the engine will show the signs.

[MikTip]

One must locate the leaking/missing coolant!

You wrote: "Been looking for puddles of coolant, can't ever see any.

Hmmm....

So if nothing is leaking externally...

Perhaps its leaking internally???

How many miles on this 2014 A3 1.6 TDI???

https://www.pistonheads.com/gassing/topic.asp?h=0&f=86&t=1409565

https://www.reddit.com/r/CarTalkUK/comments/ho9ttx/audi_a3_2014_16_tdi_coolant_loss/

https://www.audi-sport.net/xf/threads/2-0-tdi-mystery-coolant-loss.261673/

[ChatYTB]

Hi all,

Picked up a 2014 Audi A3 1.6TDI a few months ago.

Noticed that every 3-4 weeks or so the coolant light will go on and I have to top it up.

Been looking for puddles of coolant, can't ever see any.

The heater in the car is also very temperamental and doesn't work very well. When it does it will blow hot air for about 10 seconds then become lukewarm.

I have checked the carpets near the heater core and nothing damp to suggest leakage.

Apart from that the car runs fantastic and is very smooth so one of those annoying things.

Any ideas?

Best thing is to pour UV light detector leak fluid
You just pour little bit into coolant and let it circulate
And go for spin drive fast so you will create higher pressure and then use uv light to see where the leak is

https://www.thesafetysupplycompany.co.uk/p/9424232/coolant-system-leak-detection-dye----ra-rld2.html?gclid=Cj0KCQjwmZejBhC_ARIsAGhCqnd7hXW6-t9x08Cy31jlzL4oIvv6oorjZxigtZt5XW5Cg-M6bM218s8aAuxXEALw_wcB

https://youtu.be/rDuGeQnMOzk

[emoore99]

So an update I heard this hissing noise as I was driving so pulled over to see what it's about. Looks like coolant is leaking out through here. I've swapped the reservoir cap for now to see if that does anything. Any ideas?

Would love to fix this, it's really doing my head in lol

305461
305462

[MikTip]

I'd say get a new tank. Fantastic plastic.

[evo v]

I'd say get a new tank. Fantastic plastic.

Second that. I had to replace mine last year at 150K miles. The plastic was detiorating and had a small leak.

[ChatYTB]

So an update I heard this hissing noise as I was driving so pulled over to see what it's about. Looks like coolant is leaking out through here. I've swapped the reservoir cap for now to see if that does anything. Any ideas?

Would love to fix this, it's really doing my head in lol

305461
305462

There is nothing wrong with your reservoir tank
It is just dirty .. Give it nice clean and put it back ..
The reason there is "safe guard " or would say save guard canal on top of the reservoir is because when cooling system is over pressured it must come out from small canal you marked that means you have problem or blockage somewhere else and coolant system is too much pressured it needs to come out from there otherwise you colling system would explode make from your car pile of scrap

That means u need to check or replace
1. Heater matrix radiator
2. Water pump
3. Auxiliary pump under engine
4. Front big radiator and its main big pump

[MikTip]

There is nothing wrong with your reservoir tank
It is just dirty .. Give it nice clean and put it back ..
The reason there is "safe guard " or would say save guard canal on top of the reservoir is because when cooling system is over pressured it must come out from small canal you marked that means you have problem or blockage somewhere else and coolant system is too much pressured it needs to come out from there otherwise you colling system would explode make from your car pile of scrap

That means u need to check or replace
1. Heater matrix radiator
2. Water pump
3. Auxiliary pump under engine
4. Front big radiator and its main big pump

The cap on top of the tank is suppose to relieve pressure at 23psi...so it doesn't explode.

https://i.ebayimg.com/images/g/4rgAAOSwpL1f6fMc/s-l500.jpg

Perhaps a new cap? or find out why the system is over pressurizing...

Looking at the tank...someone added something to the system...

My guess a leak sealer...which has probably "sealed" the entire cooling system.

[emoore99]

Well since replacing the reservoir cap on the A3 (I just put my RS5 cap on to test lol) it has improved, still skeptical of a minor leak elsewhere but will keep testing to see if there is any coolant loss.

[ChatYTB]

Well since replacing the reservoir cap on the A3 (I just put my RS5 cap on to test lol) it has improved, still skeptical of a minor leak elsewhere but will keep testing to see if there is any coolant loss.

IF u driving and u sometimes smell coolant from your air vents it is because it spewing from those holes but even from water pump where is small hole so if overpressures it will leak from there and straight it will intake to air vents
I suggest you to replace heater matrix radiator in your cockpit .. I did it and I have no leaks anymore

[ChatYTB]

The cap on top of the tank is suppose to relieve pressure at 23psi...so it doesn't explode.

https://i.ebayimg.com/images/g/4rgAAOSwpL1f6fMc/s-l500.jpg

Perhaps a new cap? or find out why the system is over pressurizing...

Looking at the tank...someone added something to the system...

My guess a leak sealer...which has probably "sealed" the entire cooling system.

Hi yeah you right it goes from opening where cap is then it leaks to the indication circle trench / channel and then there is emergency hole in that circle recessed channel when it is then released and can leak out..

[MikTip]

Hi yeah you right it goes from opening where cap is then it leaks to the indication circle trench / channel and then there is emergency hole in that circle recessed channel when it is then released and can leak out..

Thanks for confirming what I already knew...

There is something wrong with the tank! Its full of garbage! Which means someone added something to the coolant! Which is probably why its having issues!

[ChatYTB]

Thanks for confirming what I already knew...

There is something wrong with the tank! Its full of garbage! Which means someone added something to the coolant! Which is probably why its having issues!

Ordinary water . If u leave water anywhere and there is opening it will go dirty slowly like fish tank goes green

[MikTip]

Ordinary water . If u leave water anywhere and there is opening it will go dirty slowly like fish tank goes green

Ordinary water is bad in the coolant system...especially if it leaves the tank looking like the one posted above.

Either way...there is "something" wrong with that coolant system...tank, cap, ordinary water....needs to be fixed.

Ask'm if he is DIY fixing or taking it to a shop? [wrench] The Vast majority of people who post here...don't DIY and take it to a shop.

[ChatYTB]

Ordinary water is bad in the coolant system...especially if it leaves the tank looking like the one posted above.

Either way...there is "something" wrong with that coolant system...tank, cap, ordinary water....needs to be fixed.

Ask'm if he is DIY fixing or taking it to a shop? [wrench] The Vast majority of people who post here...don't DIY and take it to a shop.

I thought here ppl gathering who pimping their cars themselves no?

But yeah can be mix ..
Have you ever opened engine and made it clean ? Make it like brand new ?

[emoore99]

This morning there was some intermittent white smoke coming out of exhaust, maybe head gasket?

[ChatYTB]

This morning there was some intermittent white smoke coming out of exhaust, maybe head gasket?

That means coolant enters into engine exhaust system vaporising quickly from very hot environment causing white smoke..