HELP ME PLEASE!!!

[BillyCool]

Yes definitely a silly mistake. It’s not connected yet I’m going to leave it until the morning. Thanks for your advice mate. One last question, how would I know if I had a dodgy water pump??

Some background history.

SEAT (or VAG Group) in their inifinate wisdom created an electronic water pump that allowed the car to warm up quicker and be better with emissions (and put a big tick in that box). It had a shroud/cover that moved up and down over the impeller to alter the water flow. It reduced water flow to allow the car to warm up quicker and then allowed more water to flow when the car got hotter.

The problem is the shroud starts to stick and can cause not enough water to get round the system and you get an overheat.

The biggest challenge was that they were intermittent and it was hard to know if it was the pump or maybe the thermostat (both are prone to having issues).

One way to try and work it out is to drive the car up a hill (they call it `under load`) and see if the temp spikes as the car works harder. This can suggest the pump is failing or not performing properly and can't cope when the car gets hot. It can also mean your thermostat is stuck and restricting water flow. If the car gets hot through `normal` driving it's harder to test.

I had that problem at the start of last year and it was an arse to diagnose. In the end I had the thermostat (and housing - it's plastic and prone to fail) and the water pump (and cam belt - that was due) replaced all at the same time.

When trying to test my car, the water pump wasn't just on or off (much easier to diagnose) - it was intermittent and a pain to work out. One minute under load it was okay, then hot, then okay (the shroud sticks, causes an overheat, then pings open and drops the temp, then sticks again....)

When the pump was changed it was sticking and was replaced with a `revised` version that doesn't have the stupid widget.

So - I'd try to get your coolant levels sorted first before you start chasing anyting else. I had heater matrix, water pump and potential thermostat issues all at the same time. It was sorted once everything was changed but it wasn't much fun trying to work it out.

In terms of your coolant temp - the guage on the dash will say 90 degrees anywhere between about 80 and 98 - it will only actually show signs of overheat when the cars really hot. It's designed not to panic people as the coolant temps fluctuate all the time normally. The best thing to do is get a Carista dongle and an app like inCar Doc that will give you real time figures and you can be a bit more scientific. You can also get an app to monitor your DPF which can be useful.

 

[CardiffFR150]

Wow a lot of useful information there mate thank you for that. Your right I’m going to focus on the coolant first and work onwards from that. And of course plugging things back in when I finish a job lol. I’ve got my alarm set nice and early for tomorrow morning. Hopefully get a better result Appreciate your help mate

 

[CardiffFR150]

Some background history.

SEAT (or VAG Group) in their inifinate wisdom created an electronic water pump that allowed the car to warm up quicker and be better with emissions (and put a big tick in that box). It had a shroud/cover that moved up and down over the impeller to alter the water flow. It reduced water flow to allow the car to warm up quicker and then allowed more water to flow when the car got hotter.

The problem is the shroud starts to stick and can cause not enough water to get round the system and you get an overheat.

The biggest challenge was that they were intermittent and it was hard to know if it was the pump or maybe the thermostat (both are prone to having issues).

One way to try and work it out is to drive the car up a hill (they call it `under load`) and see if the temp spikes as the car works harder. This can suggest the pump is failing or not performing properly and can't cope when the car gets hot. It can also mean your thermostat is stuck and restricting water flow. If the car gets hot through `normal` driving it's harder to test.

I had that problem at the start of last year and it was an arse to diagnose. In the end I had the thermostat (and housing - it's plastic and prone to fail) and the water pump (and cam belt - that was due) replaced all at the same time.

When trying to test my car, the water pump wasn't just on or off (much easier to diagnose) - it was intermittent and a pain to work out. One minute under load it was okay, then hot, then okay (the shroud sticks, causes an overheat, then pings open and drops the temp, then sticks again....)

When the pump was changed it was sticking and was replaced with a `revised` version that doesn't have the stupid widget.

So - I'd try to get your coolant levels sorted first before you start chasing anyting else. I had heater matrix, water pump and potential thermostat issues all at the same time. It was sorted once everything was changed but it wasn't much fun trying to work it out.

In terms of your coolant temp - the guage on the dash will say 90 degrees anywhere between about 80 and 98 - it will only actually show signs of overheat when the cars really hot. It's designed not to panic people as the coolant temps fluctuate all the time normally. The best thing to do is get a Carista dongle and an app like inCar Doc that will give you real time figures and you can be a bit more scientific. You can also get an app to monitor your DPF which can be useful.

Hi mate. I noticed that the car overheated yesterday as I hadn’t gave the car enough time for the coolant to pass through. It was empty! I’ve been topping it up this morning and been up and down the bypass and I’m getting slightly warm air coming through. I’ve had a feel of the pipes in the footwell that go into the matrix. The top one is lukewarm and the bottom one is boiling. Do you think it’s worth taking the matrix back out and giving it another clean or even replacing it? Or do you think the problem may lay somewhere else? Cheers pal

 

[RUM4MO]

Maybe butting in here, it is always the plan for the incoming water pipe to be hotter than the outgoing water pipe, that is if the fan blowing air across the matrix is stripping heat out of it. If there was still a blockage in the matrix, the incoming water would be restricted or stalled and so not getting continuously fed with heat from the engine - or I got that bit wrong.

 

[BillyCool]

Hi mate. I noticed that the car overheated yesterday as I hadn’t gave the car enough time for the coolant to pass through. It was empty! I’ve been topping it up this morning and been up and down the bypass and I’m getting slightly warm air coming through. I’ve had a feel of the pipes in the footwell that go into the matrix. The top one is lukewarm and the bottom one is boiling. Do you think it’s worth taking the matrix back out and giving it another clean or even replacing it? Or do you think the problem may lay somewhere else? Cheers pal

I think you're maybe getting one step ahead of yourself.

Firstly, you need to sort out the overheat problem, which is suspect was simply not enough coolant and/or some air blocks due to the matrix removal.

If you've got the overheat sorted, you can then review the matrix situation.

As @RUM4MO said, the IN pipe should be hotter than the OUT pipe if the heating is on as the heat is taken out of the cooalnt. It can also potentially mean that the matrix is still restricted and the hot water (coolant) simply isn't getting through, hence the luke warm heating. I would supsect the matrix is still clogged as that is what mine used to do.

In my personal experience, a partially cleaned/un-blocked matrix is not as good as a new one. My heating was average at best when I cleaned my matrix (an improvement but not a lot). Some people have had some success through constant cleaning but for €80 why bother? For the time and effort involved to clean and replace, you know what to do now, so fit a new one and remove that uncertainty. Once that is done you will know if it sorts itself out and can then see if anything needs addressing.

Once you have a new matrix and the correct amount of coolant back in the car ( ) you have a sensible reference point to see if anything else is up.

Make sense?

 

[CardiffFR150]

I think you're maybe getting one step ahead of yourself.

Firstly, you need to sort out the overheat problem, which is suspect was simply not enough coolant and/or some air blocks due to the matrix removal.

If you've got the overheat sorted, you can then review the matrix situation.

As @RUM4MO said, the IN pipe should be hotter than the OUT pipe if the heating is on as the heat is taken out of the cooalnt. It can also potentially mean that the matrix is still restricted and the hot water (coolant) simply isn't getting through, hence the luke warm heating. I would supsect the matrix is still clogged as that is what mine used to do.

In my personal experience, a partially cleaned/un-blocked matrix is not as good as a new one. My heating was average at best when I cleaned my matrix (an improvement but not a lot). Some people have had some success through constant cleaning but for €80 why bother? For the time and effort involved to clean and replace, you know what to do now, so fit a new one and remove that uncertainty. Once that is done you will know if it sorts itself out and can then see if anything needs addressing.

Once you have a new matrix and the correct amount of coolant back in the car ( ) you have a sensible reference point to see if anything else is up.

Make sense?

Sounds like a good way to go about it. Aw you said there is two pipes that are attached to the matrix. One is cold/warm and one is VERY hot. As you said I think it’s a case of taking it back out and cleaning it over and over or just simply replacing it. My local garage quoted me £400 to replace it lol and told me the whole dash needs to come out. So your right it’s definitely worth 80 quid just to rule out the matrix side of things. With a bit of luck I’ll get some proper heat after that.

My problem with the whole heating thing happened after pouring a bottle of K-Seal into the expansion tank. I had zero heat after putting that stuff in the car.

 

[BillyCool]

Sounds like a good way to go about it. Aw you said there is two pipes that are attached to the matrix. One is cold/warm and one is VERY hot. As you said I think it’s a case of taking it back out and cleaning it over and over or just simply replacing it. My local garage quoted me £400 to replace it lol and told me the whole dash needs to come out. So your right it’s definitely worth 80 quid just to rule out the matrix side of things. With a bit of luck I’ll get some proper heat after that.

My problem with the whole heating thing happened after pouring a bottle of K-Seal into the expansion tank. I had zero heat after putting that stuff in the car.

Unfortunately, that's where you went wrong.

With an already restricted heater matrix, adding the K-Seal will just block it right up. I'd deffo fit a new one.

Why did you add the K-Seal?

SEAT quoted me £1200 to to my matrix - 8 hours labour (dash out) and then parts.

 

[CardiffFR150]

Unfortunately, that's where you went wrong.

With an already restricted heater matrix, adding the K-Seal will just block it right up. I'd deffo fit a new one.

Why did you add the K-Seal?

SEAT quoted me £1200 to to my matrix - 8 hours labour (dash out) and then parts.

Yes the heaters where not too hot before the K-seal went in but after adding that it all went tits-up. The initial reason for adding the K-Seal is rather silly. I was getting a bit of excess white smoke from the tailpipe and thought “hey” maybe I’ve got a slight leak in my head gasket! So I threw a bottle in and screwed myself lol. Then realised I only get a lot of white smoke when the engine is cold. When it warms up there’s barely any! And of course the cold weather makes it more visible. To be honest mate I’m bored shitless on lockdown trying to find problems with my car lol. Now I’ve created one

But its definitely gunna be a new matrix. Euro have them in stock for 86 quid

 

[BillyCool]

Oh well - now you know. I just hope it doesn't clog up your water pump.

I'd fit the new Matrix, fit as much fresh coolant as possible and see how you get on.

Every day is a school day!

 

[SuperV8]

Flush which part of the system?

The coolin

Sounds like a good way to go about it. Aw you said there is two pipes that are attached to the matrix. One is cold/warm and one is VERY hot. As you said I think it’s a case of taking it back out and cleaning it over and over or just simply replacing it. My local garage quoted me £400 to replace it lol and told me the whole dash needs to come out. So your right it’s definitely worth 80 quid just to rule out the matrix side of things. With a bit of luck I’ll get some proper heat after that.

My problem with the whole heating thing happened after pouring a bottle of K-Seal into the expansion tank. I had zero heat after putting that stuff in the car.

Oh no - you shouldn't add any 'mixture' to your coolant OR oil for that matter! These 'stop leak/seal/gunk/snake oil' shouldn't be used on any modern engine and are just gunk which will block up small passage ways - like you heater matrix!
However if you have had the matrix out and ran water through it I presume water comes out the other side? If so I suspect your issues are due to air locks in the system. As you can see when you take the engine cover off these cooling systems are very complex and the refill/flush procedure is rather thorough! Officially you should also use the diagnostic program to run a coolant bleed procedure.

Unless more of the gunk in your system has again blocked the matrix?

When cold, the only pump that is activated is a small electric pump on your micro circuit (EGR and heater matrix) when the engine warms your electro-mechanical main pump takes over. Put your heater on max heat, and try squeezing your heater matrix pipes. If you have a miti-vac you could also try connecting this to the small bleed hose on the header tank and see if you can suck air out to help bleed.

 

[andycupra]

it really is not difficult to bleed the system.
most people don't leave the engine running long enough with the cap off. - So take cap off, and put it somewhere where you will remember to put it back on later..
You need to fill up with coolant, turn heating up to max, then run the car, the coolant will likely drop, keep topping up as required while it runs, then leave the car running till its fully up to temperature so coolant is fully circulating and leave running till it maintains level without needing topping up. (all with cap off) Turn car off.
IMPORTANT: then continue to leave the cap OFF and leave car to cool down. like 2 hours... check level, (it will have dropped a bit as it cools), top up to level, replace cap and you should be done.

 

[danny_j]

Hi Everyone,

Just about to tackle this on the wife's Leon as I think it's the usual silica bag split which has blocked the matrix.

Just after a part number for the new matrix so I can have it ready when swapping out - does anyone know the VAG part number or valeo equivalent etc? It's a Leon Mk3 FR TDI 150.

Many thanks.

 

[CardiffFR150]

Hi Everyone,

Just about to tackle this on the wife's Leon as I think it's the usual silica bag split which has blocked the matrix.

Just after a part number for the new matrix so I can have it ready when swapping out - does anyone know the VAG part number or valeo equivalent etc? It's a Leon Mk3 FR TDI 150.

Many thanks.

Not sure of the part number but if you call Euro Car parts or GSF etc and give your registration they will give you a price. Im sure I paid around £80 for mine and fitted it myself.


Sent from my iPhone using Tapatalk

 

[BillyCool]

Hi Everyone,

Just about to tackle this on the wife's Leon as I think it's the usual silica bag split which has blocked the matrix.

Just after a part number for the new matrix so I can have it ready when swapping out - does anyone know the VAG part number or valeo equivalent etc? It's a Leon Mk3 FR TDI 150.

Many thanks.

I fitted the Valeo one on here;

715303 - 13 results found - Buycarparts.co.uk search

Parts search. Auto parts: body parts, exhaust pipes, dampers, brake discs, headlights, bumpers and other parts for Audi, BMW, Mercedes and other automotive brands – Buycarparts.co.uk

www.buycarparts.co.uk

Delivery was about 5 days. At the time there were none in the UK.

If you need any more help or instructions, I have written a short guide that goes well with the existing You Tube video.

 

[mark garlick]

Had problems with Seat Leon Mk3 FR hardly any heat. Took to garage & said the matrix was blocked because the silicon bag had burst.
Matrix changed & new expansion chamber fitted - ok for a while but slowly lost cabin heat. Took back to garage matrix removed & flushed through again. Ok for a couple of weeks but now no heat on drivers side!
First trip to garage cost over £500 & second visit £200 - not sure whether to clean out myself, get rid of car or live with it. Maybe I should get back on to the garage.
Ironically I played around with the old matrix & managed to clear it out using Mr Muscle & an air line.
Shocking idea to fit a silicon bag in the system & will probably steer clear of the VW group in the future.

 

[BillyCool]

Had problems with Seat Leon Mk3 FR hardly any heat. Took to garage & said the matrix was blocked because the silicon bag had burst.
Matrix changed & new expansion chamber fitted - ok for a while but slowly lost cabin heat. Took back to garage matrix removed & flushed through again. Ok for a couple of weeks but now no heat on drivers side!
First trip to garage cost over £500 & second visit £200 - not sure whether to clean out myself, get rid of car or live with it. Maybe I should get back on to the garage.
Ironically I played around with the old matrix & managed to clear it out using Mr Muscle & an air line.
Shocking idea to fit a silicon bag in the system & will probably steer clear of the VW group in the future.

I feel your pain. It's a cr@p system.

I did mine myself and it cost me €90 for the matrix from Europe. The problem is that it's a combination of the silicant gel and casting sand from the engine block (another known issue) that clogs things up. My matrix had more `grit` than gel in it. My thermostat housing was also a good place to trap the debris. You could easily still have plenty of crap in the system.

I find that flushing a blocked matrix only buys you a few weeks at best. For the time and effort (less than 2 hours) to do it yourself, I'd just fit a new one. VAG service bok says 8 hours and dash out but there is a good workaround.

The system is also hard to flush properly without VCDS and special pumps (thanks VAG). I just dumped as much coolant as I could (bottom rad hose) and refilled (water pump and thermostat housing done at same time so most coolant was removed). Over 18 months later it seems okay but I've not had the heating on recently! It is happens again I'll just fit another matrix and flush the coolant.

Newer VAG cars seem to have the next gen coolant without silicant. I've just gone for the old school coolant change every 2 or 3 years like we used to before the tea bag addition.

It's a shame as it's been a pain in the @rse but I do like the car.

 

[andycupra]

this silicon bag issue needs to be taken up with VAG. surely a recall or repairs should be offered. its so common by the sounds of it

 

[RUM4MO]

It almost sounds like VAG has addressed this issue, and dropped G13 and moved to G12EVO, ie BASF coolant G65!

This sort of thing it seems, in VAG world, is a suitable fix - and bu**ar all customers who have been left with problems, nice?

 

[Oldun]

Guys, for future reference, I've just changed the heater matrix on a Mk3 leon 2.0 tdi Fr.. Fairly straightforward to be fair. Now the car has toasty heating again I thought I'd have a play with the old (blocked matrix) 1) Dissolved a dishwasher tablet in boiling water and filled matrix (has to fill inlet and outlet sides) capacity is minimal. Left to Soak for a couple of hours... note :the face of the matrix wasn't even getting warm 2)Drained and flushed through with garden hose for 5 mins ( after which time water was passing through the matrix. 3) Did a 2nd fill with boiling dishwasher water and soaked for half hour... note: face of the matrix was now quite warm and only had to fill one side to completely fill it. 4) Again flushed with garden hose and water running freely through the matrix 5) To make sure blew through with compressed air (I have a compressor) but probably not needed. I'm now convinced my old matrix is completely clear and wished I hadn't rushed out and spent £165 on a new matrix. So if you have the time then following this procedure before buying a new matrix could save you a Bob or two.

 

[RUM4MO]

I suppose the plan now might be to store this original matrix safely in a protective box after it has dried out completely, then, if there is still some sediment still trapped elsewhere in the cooling circuit and it moves through the system, it will again get trapped in the new matrix, if or when it does block the new matrix, it will be a simple job to swop them over and repeat - ideally this will not be necessary - but.