Fr 184 coolant issue (yet another)

[Lord Percy]

Hi, I have a 2014 model with 120k on the clock. Recently got the coolant low warning and have since had the timing chain, water pump, faulty aux. water pump and coolant expansion bowl replaced. The car ran without any more leaks for a month but has now started again, several times in the last few days. The liquid appears to come from the expansion bowl but I may have seen white smoke from the exhaust whilst driving, not 100% sure.

2 garages have looked at it but neither are certain what the issue is - there appears to be no physical leak to be seen. I have the dilemma of replacing the heater matrix or the egr cooler or both. Heat is equal from both sides of the car vents so thinking it may not be the matrix?

I've just spent about £1500 on it so a bit reluctant to get rid, but I don't want to keep throwing money at it when it's quite an old car and said repairs may not be the problem, so potentially more wasted money.

Anybody got any advice regarding this, it would be greatly appreciated.

 

[Walone]

Hi, I have a 2014 model with 120k on the clock. Recently got the coolant low warning and have since had the timing chain, water pump, faulty aux. water pump and coolant expansion bowl replaced. The car ran without any more leaks for a month but has now started again, several times in the last few days. The liquid appears to come from the expansion bowl but I may have seen white smoke from the exhaust whilst driving, not 100% sure.

2 garages have looked at it but neither are certain what the issue is - there appears to be no physical leak to be seen. I have the dilemma of replacing the heater matrix or the egr cooler or both. Heat is equal from both sides of the car vents so thinking it may not be the matrix?

I've just spent about £1500 on it so a bit reluctant to get rid, but I don't want to keep throwing money at it when it's quite an old car and said repairs may not be the problem, so potentially more wasted money.

Anybody got any advice regarding this, it would be greatly appreciated.

If you haven't tried it, wait until the engine is cold (if possible overnight), loosen the coolant filler cap slowly and remove it, top up coolant to max mark then refit the cap. You may need to repeat this a few times. If coolant is escaping from the filler cap you may need a new one.

 

[Lord Percy]

Cheers, the cap is brand new, along with the vessel. I'd like to think it's not that at fault but I won't discount it yet.

From what I've been told the filler cap acts as a relief valve so I'm assuming pressure is coming from somewhere and forcing the coolant out.

 

[SuperV8]

Presuming you have a TDI? - in which case you had the timing belt changed - they don't have chains.
If the matrix is blocked/restricted you typically loose coolant after a DPF regen and can go from max to min in one event - with coolant escape visible near your expansion tank (due to local overheating of your micro coolant circuit which contains your EGR cooler and matrix).

If your EGR cooler is leaking that would usually be more of a slow gradual coolant loss into your exhaust.
You also have a heat exchanger in your inlet manifold which can leak coolant internally to the engine! again usually a slow gradual loss depending on how big the leak is!

The matrix is much cheaper/simpler to change than your EGR cooler. It would depend on how the matrix is blocked as to how it effects your cabin vents temp. If half blocked then you would find a difference in temperature between your LH/RH vents - but if it has blocked/restricted over its full area then there would be no temperature difference LH/RH.

 

[Lord Percy]

Thanks SuperV8, this is really useful, the best advice/info I've had yet from anywhere!

The leak happens in one go, not gradually. I'd say about half a litre to one litre at a time. Think I'm gonna bite the bullet and get the matrix changed, I'll update when done as it may help others.

Oh yeah, it is a TDI and it was a belt change, not a chain

Cheers.

 

[SuperV8]

Matrix change is quite simple - lots on hear about it.
A few torx screws to remove the glovebox, the blower motor and the tunnel side trim and you can pull the matrix out into the passenger footwell.

 

[Lord Percy]

Thanks, I'm sure I could do it but I'd rather get my regular garage to fit it - I'm really not a car repair type person. I've also read that the system needs flushing before fitting and I'm just not confident enough to do it. I've had a quote for £430 for a genuine Seat one fitted so thought that was pretty good.

Cheers again.

 

[SuperV8]

Sure, comments were really just to let you know it's not a difficult job - less than 2 hours, so you can evaluate to see if a garage quote seem reasonable.
Yes, best to flush the cooling system before fitting your new matrix.

 

[BillyCool]

As above - replacing the Matrix is probably cheaper and less involved than an EGR cooler. £430 for a genuine matrix is better than SEAT's £1500 list price.

Another way of trying to see if the coolant loss is related to a blocked matrix and subsequent DPF regen is to monitor when it does a regen.

I have the Carista dongle and VAG DPF app. I can then see when my DPF regens and see if that ties in with the coolant loss. Directly after the regen you can see if there is any coolant loss around the expansion tank. As the system is pressurised it sometimes takes for it to cool down overnight and the pressure to drop before you get the low level warning.

https://www.amazon.co.uk/gp/product/B0BBS73F6J/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

If you've had a new water pump, most of your coolant would have been drained and replaced anyway. An additional flush can't do any harm though. On my car, the matrix and thermostat housing seemed to trap the most debris.

Hope you get it sorted.

 

[Lord Percy]

Thanks Billycool, that's really helpful

 

[Lord Percy]

Just thought I'd post an update, may be helpful to someone at some point in time.

I had the heater matrix replaced 8 days ago, the system was full of crap. The mechanic said that they tried to put liquid through before the change but it was definitely blocked, after the change it was fine. I've not had any leaks yet but I have driven for a month in the past and also had no leaks so it's not confirmed as fixed just yet.

Something I have noticed is that the fan would run a lot after a journey before the replacement but I've not heard it once since it was done. Not sure if that's just coincidence?

 

[Dreavens]

Just thought I'd post an update, may be helpful to someone at some point in time.

I had the heater matrix replaced 8 days ago, the system was full of crap. The mechanic said that they tried to put liquid through before the change but it was definitely blocked, after the change it was fine. I've not had any leaks yet but I have driven for a month in the past and also had no leaks so it's not confirmed as fixed just yet.

Something I have noticed is that the fan would run a lot after a journey before the replacement but I've not heard it once since it was done. Not sure if that's just coincidence?

Hey Percy, how's it going with the car these days? Any updates? I suspect a similair problem on my end

 

[Lord Percy]

Hey Dreavens, it's all been good so far. No leaks at all.

The big clue for me was SuperV8 saying that the EGR cooler would be a gradual loss, which it wasn't, it was in one quick blast.

I did not have the different heat outputs from the blowers so that was a bit of a red herring and caused a bit of delayed decision making on my part.

Hope you get sorted.

 

[Dreavens]

Hey Dreavens, it's all been good so far. No leaks at all.

The big clue for me was SuperV8 saying that the EGR cooler would be a gradual loss, which it wasn't, it was in one quick blast.

I did not have the different heat outputs from the blowers so that was a bit of a red herring and caused a bit of delayed decision making on my part.

Hope you get sorted.

Glad to hear! Yeah I got no heat at all coming out of it currently and like you on occasion it just drinks the coolant away.

 

[Lord Percy]

Well, I don't know much about cars so I'm probably not the best to offer advice, but it certainly sounds similar. I didn't have heating issues, though. Is there coolant on the expansion vessel?

 

[Dreavens]

Well, I don't know much about cars so I'm probably not the best to offer advice, but it certainly sounds similar. I didn't have heating issues, though. Is there coolant on the expansion vessel?

Yeah it has a bit of residue on it and a small rundown stream from the blow off tube