2014 Leon FR Coolant issues

[NoName22]

So I have a 2014 DSG 150bhp 2.0 tdi and coolant is disappearing..... I've read plenty online about this issue but not many have resolved without getting rid.... Here is what I have done

EGR replaced
Water pump replaced
New bottle
All hosing checked
Pressure Tested

I don't want to sell the car because I love it.... But I am starting to think it is an issue with the heater matrix because the heat inside the car isn't fantastic and it takes ages for the car to heat up.... I've noticed the driver footwear never gets warm but the passenger side gets very warm......definitely no leaks in the cabin either.... It's gone to a stage where I cannot even drive it on the motorway because it really uses coolant then..... Surely someone on here has come across this before?

 

[fumeshroom]

So I have a 2014 DSG 150bhp 2.0 tdi and coolant is disappearing..... I've read plenty online about this issue but not many have resolved without getting rid.... Here is what I have done

EGR replaced
Water pump replaced
New bottle
All hosing checked
Pressure Tested

I don't want to sell the car because I love it.... But I am starting to think it is an issue with the heater matrix because the heat inside the car isn't fantastic and it takes ages for the car to heat up.... I've noticed the driver footwear never gets warm but the passenger side gets very warm......definitely no leaks in the cabin either.... It's gone to a stage where I cannot even drive it on the motorway because it really uses coolant then..... Surely someone on here has come across this before?

Hi, unfortunately it sounds like your car has suffered from the silica bag bursting in the coolant tank and subsequently caused a blocked heater matrix.
I have a ‘63 leon tdi and it happened to me too, with almost identical symptoms as to what you’ve described. That would tie in with what you’re saying about half the car blowing warm and the other half not.
The other thing I was getting was a red emergency light and warning buzzer coming up on the dash telling me to stop the car and switch off the engine. Once I left it a few minutes and then unscrewed the coolant cap, the coolant returned, which suggested there was some sort of vacuum which I knew wasn’t right.

I had to get the system flushed out and have a new heating part (can’t remember what it was now) but it cost me around £700 all in all mainly due to the time (labour) it takes to get the system flushed out.
If I ever get another car that has a silica bag inside the coolant tank, I’m removing it as soon as the warranty is up because it was a bill I potentially could have avoided, had I known about it before hand. It’s quite common on 2013-2014 Leon’s and if I remember correctly the problem is mainly an issue on cars which have dual zone climate control.
The independent garage I went to said sometimes they were doing one of these a week so it’s not uncommon.
I will say since I had the work done in Feb the car hasn’t missed a beat.

 

[Mr Pig]

They stopped fitting the bag, right?

 

[BillyCool]

So I have a 2014 DSG 150bhp 2.0 tdi and coolant is disappearing..... I've read plenty online about this issue but not many have resolved without getting rid.... Here is what I have done

EGR replaced
Water pump replaced
New bottle
All hosing checked
Pressure Tested

I don't want to sell the car because I love it.... But I am starting to think it is an issue with the heater matrix because the heat inside the car isn't fantastic and it takes ages for the car to heat up.... I've noticed the driver footwear never gets warm but the passenger side gets very warm......definitely no leaks in the cabin either.... It's gone to a stage where I cannot even drive it on the motorway because it really uses coolant then..... Surely someone on here has come across this before?

This is from another post/thread about the same issue. I suspect that your heater matrix will need replacing:

This is quite well documented in a couple of other threads, so I'll try not to repeat too much. I did a lot of research on the same thing (2014 Leon TDi 184) and most of the info I gleaned from these and then added my own contribution.

You've already got the first part of the jigsaw, silicant bag split and blocked heater matrix. The coolant loss usually comes after a DPF regen when your super hot (600 degrees) EGR tries to cool down (as it uses the blocked heater matrix circuit). The coolant effectively boils and shoots out of the overpressure release just under the lid of the header/expansion tank (hence the witness marks). Technically, there is no leak in the cooling system and the car is not overheating. As the system is pressurised it takes until the car cools down for the coolant level to drop below minimum and then it gives the low level warning next time you start up (just to confuse you into thinking the the loss occured when parked up).

In terms of cost. SEAT also quoted me c.£800+parts to sort it. Using info from this forum and a couple of other places, I got the matrix from Europe for £75 (UK had none due to so many being retro-fitted) and about 2 hours to remove/fit a matrix. SEAT's service doc says 8 hours to remove the whole dash (hence the eye watering quote), but there is a good workaround/cheat. Apart from the research time and a bit of trial an error, it cost me less than £100 and a few hours of my time.

Flushing the heater core only part cleans it and it's not really worth the hassle. May as well stick a new one in (mine has been perfect ever since).

If you have time to trawl through both of these, you'll be wiser and hopefully about £1000 better off.

https://forums.seatcupra.net/index....otorway-journeys-or-high-speeds.454370/page-8

https://forums.seatcupra.net/index.php?threads/leon-fr-tdi-184-coolant-loss.459546/#post-4915093

Feel free to ping me a DM if you need help with anything.

 

[Sjdickso]

Same issue with my 2013 184, was a blocked heater matrix, new revised header tank no bag and new heater matrix.

 

[SuperV8]

Yes they stopped fitting the silica bag in the header tank but the issue still exists.
I was told by a VW master tech that it is also down to leftover fine sand from the casting of the engine.
I've had this exact issue, the heater matrix blocks up as it has the smallest passageways in the coolant system, so initially the drivers side will blow cold/passengers side will still be hot - as the matrix gradually blocks up. Then when it tries to do a DPF re-generation this causes a lot of heat in the cooling system, and if you switch off the engine with a blocked heater matrix there is no coolant flow through the EGR micro circuit so it over pressurizes and comes out the header tank cap. I bet you can see traces of coolant around your header tank?
The VW 'fix' is several drains and flushes with cleaning solution along with a new heater matrix.
The heater matrix on the leon MK3 is easy to remove, and i've also found that standard garden hose adapters/o-ring fit perfectly in the ends of the heater matrix - so you can flow good & high pressure water back through the matrix.
I've done this three times now, and each time it has lasted longer before needing to do it again - my 'hope' is this will eventually filter/clear out the sand from the system so it won't happen again, as there is a finite amount of sand in the system. I'd like to back flush the rest of the system, but I think this is tricky as there are some electronic valves which need actuating? though I guess you could do the radiator easily enough.
I collect the water I flow through the matrix to clean it each time and you can clearly see a collection of find sand in the bottom of the bucket.
I don't think just fitting a new heater matrix will be a permanent solution (this depends how much left over sand you have in your system which i'm sure will vary!)

Tom.

 

[Sjdickso]

@SuperV8 did you flush every time time or replace the matrix at any time?

 

[SuperV8]

I have flushed the matrix 3 times now, which for me works for a few months then gradually blocks up again, but I am finding each time I do it it lasts longer before blocking again. There is only a finite amount of sand in the cooling system so i'm hoping at some point it will have filtered enough sand out not to get blocked again! and now i'm quite fast at getting the matrix out!
I haven't brought a new matrix, I did look at buying one but then I found that a garden hose o-ring adapter fit the matrix perfectly so I can flow so good high pressure water back through the matrix - which clears it out well. And I would be annoyed to fit a new Matrix (without doing a full system flush/clean) and have it block up again!, although it seems some have done that and it's working for them.

Tom.