Coolant loss from tank on motorway journeys or high speeds

YKFR

Active Member
Jul 23, 2019
57
9
Hi,

I am new to this. So sorry in advance if I seem like a noob. So I recently bought a 2014 Seat Leon FR 184 model. It was a company owned car and has done about 120 k. I am the 1st real private owner. The company have maintained the car well according to the service stamps provided to myself from the person I bought the car off.

The cambelt and water pump were also changed in March 2019 (By SEAT). The car runs fine during urban travels. However, when I took the car out to motorway to get at high speeds of about 70/80 mph, I realized next day that the coolant tank was completely empty. I got a dashboard sign to check it.

After that I got the car serviced and got most things changed including coolant and same thing happened again. My mechanic then poured in K-Seal after he could not find a leak. I then took the car on a 17 miles journey and reaching high speeds of about 70 mph. I parked up the car and found the coolant tank to be 3/4 empty again (keeping in mind that it was fine for 5 days).

I have now taken it to another garage to get a second opinion. They took could not find any leaks either. They checked my engine and other pipes and said it all looks and runs fine. They have now ordered a new coolant tank as they think it could be the tank which has worn out or the water pump is at fault, where at high speeds the water which is coming out of the pump is evaporating as its hot and therefore, no puddles on the ground.

Anyone else got any opinions on this matter? Sorry for the long thread.

Thanks
YKFR
 

bgb

Active Member
Jan 22, 2019
600
316
Hi,

I am new to this. So sorry in advance if I seem like a noob. So I recently bought a 2014 Seat Leon FR 184 model. It was a company owned car and has done about 120 k. I am the 1st real private owner. The company have maintained the car well according to the service stamps provided to myself from the person I bought the car off.

The cambelt and water pump were also changed in March 2019 (By SEAT). The car runs fine during urban travels. However, when I took the car out to motorway to get at high speeds of about 70/80 mph, I realized next day that the coolant tank was completely empty. I got a dashboard sign to check it.

After that I got the car serviced and got most things changed including coolant and same thing happened again. My mechanic then poured in K-Seal after he could not find a leak. I then took the car on a 17 miles journey and reaching high speeds of about 70 mph. I parked up the car and found the coolant tank to be 3/4 empty again (keeping in mind that it was fine for 5 days).

I have now taken it to another garage to get a second opinion. They took could not find any leaks either. They checked my engine and other pipes and said it all looks and runs fine. They have now ordered a new coolant tank as they think it could be the tank which has worn out or the water pump is at fault, where at high speeds the water which is coming out of the pump is evaporating as its hot and therefore, no puddles on the ground.

Anyone else got any opinions on this matter? Sorry for the long thread.

Thanks
YKFR

Same issue on my GTD and common among VAG diesel oil burners. I would point towards your heater matrix etc being clogged causing coolant to appear 'lost'. Does your heating work correctly? More so on one side or non at all?

Also, is there no trace of the coolant? No white specs over the engine bay? Particularly above/around the filler cap? In the end on my GTD, i replaced the coolant cap with a newer version which for some reason seemed to work in terms of keeping the coolant in, but the heater matrix still periodically blocked.

I would advise going to a good independent for a coolant flush and stay away from people who use 'hole fillers'. The heater matrix is made up of tiny capillaries that easily become blocked, (hence the advice stay away from K-Seal etc) with some citing the silicone bag within the coolant tank as the culprit. Google 'golf heater matrix block' or 'Golf/A3/Leon no heat one side' and it soon takes you on a journey of knowing its a more common fault than you think!

VW tried telling me i introduced foreign bodies into the tank, which is a lie. Turned out the 'sand' they found was left over engine block casting sand...
 

YKFR

Active Member
Jul 23, 2019
57
9
Same issue on my GTD and common among VAG diesel oil burners. I would point towards your heater matrix etc being clogged causing coolant to appear 'lost'. Does your heating work correctly? More so on one side or non at all?

Also, is there no trace of the coolant? No white specs over the engine bay? Particularly above/around the filler cap? In the end on my GTD, i replaced the coolant cap with a newer version which for some reason seemed to work in terms of keeping the coolant in, but the heater matrix still periodically blocked.

I would advise going to a good independent for a coolant flush and stay away from people who use 'hole fillers'. The heater matrix is made up of tiny capillaries that easily become blocked, (hence the advice stay away from K-Seal etc) with some citing the silicone bag within the coolant tank as the culprit. Google 'golf heater matrix block' or 'Golf/A3/Leon no heat one side' and it soon takes you on a journey of knowing its a more common fault than you think!

VW tried telling me i introduced foreign bodies into the tank, which is a lie. Turned out the 'sand' they found was left over engine block casting sand...


Hi,

Thanks for your reply. I know of the issue you are talking about. SEAT said it may be the issue with the heating matrix. However, I dont usually use the fans anyway. And the distrbution of air is not really uneven. It takes a while for AC to kick in if I am using that function but it seems to work for both driver side and passenger side pretty equally.

Onto your next point about white patches around engine. There isn't anything as such which I or the garages have noticed. I am getting the coolant tank and the cap replaced and put in new as my garage has said that coolant maybe escaping due to poor seals.

Ill post what happens once I go for a long journey with high speed build up.

PS... Did your coolant stop getting less in your tank once you replaced the cap/tank?

Thanks
YKFR
 

bgb

Active Member
Jan 22, 2019
600
316
@YKFR

SEAT said it may be the issue with the heating matrix. However, I dont usually use the fans anyway. And the distrbution of air is not really uneven. It takes a while for AC to kick in if I am using that function but it seems to work for both driver side and passenger side pretty equally.

If you use the fans or not, AC condition, air velocity etc are not signs of coolant block unfortunately, the heater matrix works by allowing hot coolant to traverse through the capillaries that air is pushed over when you require heat from the system. This same coolant is what is seen in your overflow tank etc. You can test to see if the blockage is there yourself by looking down into the engine bay when you've had a good run, noticing two pipes entering the cabin through a silver covered partition.
20160910_132546.jpg

Grab them, if both scorching hot, there is flow, if ones hot ones not so much, the fluids arn't working around. (by grab i mean carefully!):D

There isn't anything as such which I or the garages have noticed. I am getting the coolant tank and the cap replaced and put in new as my garage has said that coolant maybe escaping due to poor seals

Unless you've cracked a head, the coolant must be going somewhere, especially if they are topping up.. mine got forced back out the expansion tank. You also say the water pump was replaced, can you locate it, does it look wet? These were well known for breaking, you may have got a revision put in that was still vulnerable.

Did your coolant stop getting less in your tank once you replaced the cap/tank

I sold the car maybe 2 months after, to a dealer and within that time it didn't loose coolant after a run but the heat was never back to 100% inside he cabin. The caps degrade over time, so when back pressure builds the logical place for it to escape is the cap, you'll hear it hissing.

On another note, do your windows fog up easily if you've left the AC on/climate control when you start in the morning? This can be a sign of coolant leaking into your cabin AC/Heating space creating moisture. Another sign of a leak :yes:

The above picture i found on this forum through google, which brought up this thread, may help you.
https://forums.seatcupra.net/index.php?threads/aircon-and-heater-doesnt-work.432793/
 

ZK_FR150

Active Member
Apr 16, 2016
221
32
Dont know if it's the same for the 184 but my 150 was leaking from the egr valve gasket onto the exhaust so coolant would just disappear over time.
Got the valve and gasket changed and no leaks since
 

YKFR

Active Member
Jul 23, 2019
57
9
@YKFR

SEAT said it may be the issue with the heating matrix. However, I dont usually use the fans anyway. And the distrbution of air is not really uneven. It takes a while for AC to kick in if I am using that function but it seems to work for both driver side and passenger side pretty equally.

If you use the fans or not, AC condition, air velocity etc are not signs of coolant block unfortunately, the heater matrix works by allowing hot coolant to traverse through the capillaries that air is pushed over when you require heat from the system. This same coolant is what is seen in your overflow tank etc. You can test to see if the blockage is there yourself by looking down into the engine bay when you've had a good run, noticing two pipes entering the cabin through a silver covered partition.
20160910_132546.jpg

Grab them, if both scorching hot, there is flow, if ones hot ones not so much, the fluids arn't working around. (by grab i mean carefully!):D

There isn't anything as such which I or the garages have noticed. I am getting the coolant tank and the cap replaced and put in new as my garage has said that coolant maybe escaping due to poor seals

Unless you've cracked a head, the coolant must be going somewhere, especially if they are topping up.. mine got forced back out the expansion tank. You also say the water pump was replaced, can you locate it, does it look wet? These were well known for breaking, you may have got a revision put in that was still vulnerable.

Did your coolant stop getting less in your tank once you replaced the cap/tank

I sold the car maybe 2 months after, to a dealer and within that time it didn't loose coolant after a run but the heat was never back to 100% inside he cabin. The caps degrade over time, so when back pressure builds the logical place for it to escape is the cap, you'll hear it hissing.

On another note, do your windows fog up easily if you've left the AC on/climate control when you start in the morning? This can be a sign of coolant leaking into your cabin AC/Heating space creating moisture. Another sign of a leak :yes:

The above picture i found on this forum through google, which brought up this thread, may help you.
https://forums.seatcupra.net/index.php?threads/aircon-and-heater-doesnt-work.432793/
Hi,

Thanks for your reply. I have got these things tested/seen by the garage. And they checked a lot of things. Again they have said it doesnt seem like heating matrix is at fault.

Also about the wear and tear of the cap... The car has done 120 k miles in 5 years. So I'm guessing that could be the cause of something. The cap and/or tank have got wornout sealing and need replacing maybe?

Im taking it step by step I Dont want to jump the gun and dive into something where I end up opening up my car and the fault is not even that deep in.

Thanks for your advice! Much needed!

YKFR
 
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YKFR

Active Member
Jul 23, 2019
57
9
Dont know if it's the same for the 184 but my 150 was leaking from the egr valve gasket onto the exhaust so coolant would just disappear over time.
Got the valve and gasket changed and no leaks since

Hi,

Thanks for your suggestion. I'll get that checked too if I can.

Thanks
YKFR
 

black_sheep

Active Member
Mar 10, 2013
1,256
585
Has anyone done a pressure test and tested for contamination from a blown head gasket?
Don't let them just throw parts at it and hope. There will be a cause.

This engine configuration is notorious for coolant issues; look at the Briskoda Skoda forums too. Issues include:

Main water pump and associated seals.
Cracked welds on EGR cooler.
Blocked/corroded heater matrix.
Cracked expansion tanks.

In addition to the above, blown head gasket/cracked cylinder head may also be causes, but after the water pump was modified the EGR cooler or heater matrix appear to be the main culprits at the moment.

I had the 184 ps VRS Octavia and had all of the same issues, and despite numerous pressure tests and hydrocarbon tests, at different main dealers, and an VAG specialist, couldn’t replicate or identify the fault. For the likely location of the leaks, the coolant either exits the system into the exhaust side of the engine, or is expelled via the expansion tank overflow.

Mine was a 77k mile in 5 years, and required 2 x water pumps (one was a catastrophic failure, coincidentally on my way home 150 miles after a pressure test, and probably as a result of running dry), expansion pressure cap (did nothing), heater matrix flush.

I also had 100k mile, 5 year 150 ps FR using the same EA288 block with no issues whatsoever, so I don’t think that mileage is necessarily a factor. This will probably be confirmed by a number of owners with the 184 ps engine that has been trouble free over a similar age/mileage.
 

YKFR

Active Member
Jul 23, 2019
57
9
This engine configuration is notorious for coolant issues; look at the Briskoda Skoda forums too. Issues include:

Main water pump and associated seals.
Cracked welds on EGR cooler.
Blocked/corroded heater matrix.
Cracked expansion tanks.

In addition to the above, blown head gasket/cracked cylinder head may also be causes, but after the water pump was modified the EGR cooler or heater matrix appear to be the main culprits at the moment.

I had the 184 ps VRS Octavia and had all of the same issues, and despite numerous pressure tests and hydrocarbon tests, at different main dealers, and an VAG specialist, couldn’t replicate or identify the fault. For the likely location of the leaks, the coolant either exits the system into the exhaust side of the engine, or is expelled via the expansion tank overflow.

Mine was a 77k mile in 5 years, and required 2 x water pumps (one was a catastrophic failure, coincidentally on my way home 150 miles after a pressure test, and probably as a result of running dry), expansion pressure cap (did nothing), heater matrix flush.

I also had 100k mile, 5 year 150 ps FR using the same EA288 block with no issues whatsoever, so I don’t think that mileage is necessarily a factor. This will probably be confirmed by a number of owners with the 184 ps engine that has been trouble free over a similar age/mileage.

Thanks for your input, so what do you suggest I do? Because if these issues are so common then I dont know how these companies haven't gotten a bad name yet. You dont expect VAG cars to be failing like this. It's so frustrating.

I upgraded from a Citroen C3 and it never gave me any such issues. This is such a headache and money waster.

Should I get a pressure test done if the coolant drops in the tank again or should I just get the water pump looked at? Pressure test is £50. I'm really annoyed and flustered.

Thanks
YKFR
 

black_sheep

Active Member
Mar 10, 2013
1,256
585
You say that you’ve recently purchased the car - where did you buy it from? Depending on how recently/where from will depend upon what action to take; if from a dealer/garage the vehicle should have been supplied with a warranty or option to return with money back - your argument is that the fault was present at the time of purchase. Have a read of the consumer rights act 2015, or google ‘consumer rights second hand car purchase’ - time is very much of the essence here, and you normally have to give the supplier (your contract is with them) the opportunity to make good.

Some info here: https://www.moneyadviceservice.org.uk/en/articles/your-rights-if-something-is-wrong-with-your-car

Also, you mentioned that the water pump (and assuming timing belt kit) was replaced by Seat - this is warrantied for 2 years for parts.

Unfortunately, the pressure test is the start of the diagnostic journey, as the electronic diagnostic system will not throw up any fault codes, other than the low coolant warning; however, in my experience, it is unlikely to identify the fault.

You said that you’ve taken the vehicle to a different garage for a second opinion, and that they can see no white (or residue under UV light?) - this would indicate that the leak is either internal to exhaust (otherwise your oil would be contaminated), or is being forced out of the expansion tank overflow. Again, difficult to diagnose poorly performing heater matrix - if performing correctly it is almost too hot to touch, whereas poorly performing one starts warm, but quickly turns luke warm/cold, but this can be confused with the climate control fluctuating hot/cold to cool cabin.

The heater matrix is c.£100 part, and can be removed without taking out the dash on the Leon - there was a DIY thread on here recently. EGR coolers are c.£250. Unfortunately, it’s the labour costs which will bump both of these up.

In terms of the VAG brand, I’ve owned 14 from all marques (Audi, VW, Skoda and Seat) in the past decade - my Skoda was the only one with mechanical issues (missing spot weld in bulkhead causing water to leak into cabin and the coolant fault); the rest were usually electrical/software related, and easily resolved.
 

YKFR

Active Member
Jul 23, 2019
57
9
Dont know if it's the same for the 184 but my 150 was leaking from the egr valve gasket onto the exhaust so coolant would just disappear over time.
Got the valve and gasket changed and no leaks since

Hi,

Could you physically see or hear the leaks when you took it to garage? Or was there a puddle? How did your garage diagnose this issue? Because coolant falling onto exhaust would just evaporate (when car is hot).

Thanks
 

YKFR

Active Member
Jul 23, 2019
57
9
You say that you’ve recently purchased the car - where did you buy it from? Depending on how recently/where from will depend upon what action to take; if from a dealer/garage the vehicle should have been supplied with a warranty or option to return with money back - your argument is that the fault was present at the time of purchase. Have a read of the consumer rights act 2015, or google ‘consumer rights second hand car purchase’ - time is very much of the essence here, and you normally have to give the supplier (your contract is with them) the opportunity to make good.

Some info here: https://www.moneyadviceservice.org.uk/en/articles/your-rights-if-something-is-wrong-with-your-car

Also, you mentioned that the water pump (and assuming timing belt kit) was replaced by Seat - this is warrantied for 2 years for parts.

Unfortunately, the pressure test is the start of the diagnostic journey, as the electronic diagnostic system will not throw up any fault codes, other than the low coolant warning; however, in my experience, it is unlikely to identify the fault.

You said that you’ve taken the vehicle to a different garage for a second opinion, and that they can see no white (or residue under UV light?) - this would indicate that the leak is either internal to exhaust (otherwise your oil would be contaminated), or is being forced out of the expansion tank overflow. Again, difficult to diagnose poorly performing heater matrix - if performing correctly it is almost too hot to touch, whereas poorly performing one starts warm, but quickly turns luke warm/cold, but this can be confused with the climate control fluctuating hot/cold to cool cabin.

The heater matrix is c.£100 part, and can be removed without taking out the dash on the Leon - there was a DIY thread on here recently. EGR coolers are c.£250. Unfortunately, it’s the labour costs which will bump both of these up.

In terms of the VAG brand, I’ve owned 14 from all marques (Audi, VW, Skoda and Seat) in the past decade - my Skoda was the only one with mechanical issues (missing spot weld in bulkhead causing water to leak into cabin and the coolant fault); the rest were usually electrical/software related, and easily resolved.

The car was bought from a dealer yes. I have been told to try and contact the dealer but what if the dealer says they did not know of the issue. Or that it was fine when they had the car. The dealer bought the car from an auction so I dont think there is much help there for me??

I have had a look at different parts and repairs but I can't just jump into it and get everything replaced, it will cost too much. And I can't afford it.

Is pressure test really effective? Because there are no visual leaks. And I suspect that it is either the expansion tank/cap or the EGR valve gasket. I need to know how can I diagnose the EGR valve leak. Will a pressure test show me if EGR valve is the problem?

Thanks
 

bgb

Active Member
Jan 22, 2019
600
316
The car was bought from a dealer yes. I have been told to try and contact the dealer but what if the dealer says they did not know of the issue. Or that it was fine when they had the car. The dealer bought the car from an auction so I dont think there is much help there for me??

I have had a look at different parts and repairs but I can't just jump into it and get everything replaced, it will cost too much. And I can't afford it.

Is pressure test really effective? Because there are no visual leaks. And I suspect that it is either the expansion tank/cap or the EGR valve gasket. I need to know how can I diagnose the EGR valve leak. Will a pressure test show me if EGR valve is the problem?

Thanks

If brought form a dealer I would stop taking it anywhere else but that said dealer. You are giving them reason to deny warranty or claims because of someone else meddling with it, ie pouring in a sealant fluid!

How long ago did you buy it? Main SEAT dealer? Doesn't matter where they got it from, they sold to you as a trader so you have a recourse of action should a problem show itself. I would of thought you'd of got a 3 month warranty as a minimum?
 

YKFR

Active Member
Jul 23, 2019
57
9
If brought form a dealer I would stop taking it anywhere else but that said dealer. You are giving them reason to deny warranty or claims because of someone else meddling with it, ie pouring in a sealant fluid!

How long ago did you buy it? Main SEAT dealer? Doesn't matter where they got it from, they sold to you as a trader so you have a recourse of action should a problem show itself. I would of thought you'd of got a 3 month warranty as a minimum?

I bought the car from a trader/dealer, he bought the car from an auction. This was nearly a month ago. And no the trader didn't provide any sort of warranty.

What if they deny any knowledge of any fault? Is there still a way forward?
 

ZK_FR150

Active Member
Apr 16, 2016
221
32
Hi,

Could you physically see or hear the leaks when you took it to garage? Or was there a puddle? How did your garage diagnose this issue? Because coolant falling onto exhaust would just evaporate (when car is hot).

Thanks
Hi

I just took it to the seat dealer and they diagnosed it as that, I'm not sure how they diagnosed it though.
I couldn't see any leaks or anything when I looked around, the part is located behind the turbo so it's not easy to access.
I'm just going on what they told me and as it was evaporating there isn't any visual clues from what I could tell apart from the tank emptying gradually.
I don't think it was a cheap fix either something around £400 plus.
Once replaced it did fix it.
 
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