Mysterious Coolant Leak

[joel bint]

Hi all,

I have a 2014 Audi A3 8V 2.0 tdi (97k miles)

for around a year now I have had a pretty persistent Coolant leak in my car.  I have never been able to track down the route of the problem.

I have to refill my coolant around every 10 days as it quite literally disappears. I have taken it to multiple garages and even they couldn't find the problem, as all garages do, they quote you the most expensive job, replacing the head gasket (£900 just to strip the engine!) so I gave up with them. no internal leak, to residue within any part of the oil so I self-diagnosed that the head gasket was not the problem. 

the other day while driving i noticed my radiator kicked in, i decided to pull over, and to my surprise, I finally saw a puddle of coolant coming out from the actual reservoir. I don't think anyone would ever be happy to see a coolant leak, but I was buzzing. 😄

cut long story short, i still cannot identify where or what the problem is. I have total coolant loss, a burning smell coming from the tank itself,  no heat in my cabin, and back pressure in the system. My only thought is a blocked heater matrix but I know that is a labour-intensive job. i want to bleed my coolant system and flush my heater matrix to help me get to the problem. 

could someone be able to help me as i don't have much experience with cars and would like any insight on what it could be? Also, I would like to know how I flush my coolant system.

 

thanks in advance 

[cliffcoggin]

A frequent cause of invisible coolant loss is the EGR cooler. That you now have a visible loss from the reservoir might suggest the hole in the EGR cooler is now big enough to allow blow back. The only way to be sure is to remove the EGR cooler which I believe, as I have never done it, is a devil of a job.

[Magnet]

You may also like to eliminate the simple things first, and replace the reservoir cap with a good quality new one. 
Kind regards,

Gareth.