HELP ME PLEASE!!!

Brian Gordon-Stables

Active Member
Jan 16, 2020
368
134
Leicestershire, UK
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.
 
Last edited:
  • Like
Reactions: CardiffFR150
Jan 5, 2021
26
11
Cardiff
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:rolleyes: Appreciate your help mate
 
Jan 5, 2021
26
11
Cardiff
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

Active Member
Jun 4, 2008
6,488
521
South Scotland
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.
 
  • Like
Reactions: CardiffFR150

Brian Gordon-Stables

Active Member
Jan 16, 2020
368
134
Leicestershire, UK
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?
 
  • Like
Reactions: CardiffFR150
Jan 5, 2021
26
11
Cardiff
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.
 

Brian Gordon-Stables

Active Member
Jan 16, 2020
368
134
Leicestershire, UK
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.
 
  • Like
Reactions: CardiffFR150
Jan 5, 2021
26
11
Cardiff
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:rolleyes:

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

SuperV8

Active Member
May 30, 2019
150
55
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.
:oops: 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

status subject to change
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.
 
Last edited:
Christ Knott Insurance - Competitive quotes for forum members