Hi everybody 

Im from Denmark and new to this forum and I hope one of you can help me.

I have a question about my 2018 Superb 2.0 tdi - 182.000 km/113.000 miles

I have just noticed that it is has startet to use a little coolant. When I first found out, It has droppet about 5 mm i the expansiontank in two month and 3000 km/1900 miles. Now, the second time it has dropped 2 mm in a month and 1000 km/6-700 miles. 

No signs of eny leaks at all. It is probably not enough to see enything enyway.

I makes me nerveus, because I have had replaced a VW tdi engine before, due to a cracked cylinder head. It started the same way and I don´t wan´t to go there again 😢

I know it can be caused by several things(most likely waterpump) and some says its normal, they start using a little water. Is it? I never had a car that used water without some kind of leak, it has to go somewhere?

Is it possible to have it tested when it only looses that little coolant. Im thinking it´s not possible to pressure test it or it want say enything for sure. Are there enyway to tell whats wrong for sure, before starting to replace parts?

 

 

 

Hi welcome.

 

I will ask if a Moderator can move your post (thread) to the 'Skoda Superb Mk III (2015 - 2023)' forum as your questions may be model/engine specific plus I think you would get more response there

 

Or you could do a forum 'Search' for your subject within the 'Skoda Superb Mk III (2015 - 2023)' forum. - https://www.briskoda.net/forums/forum/299-skoda-superb-mk-iii-2015-2023/

 

Hope that helps.

 

Thank you very much 🙏

As you already mentioned, it could be the waterpump. It’s well known issue. Very unlikely to be a cracked cylinder head or gasket unless the car has been overheated.

 

It could also be the egr cooler, some folks in Bulgarian forum had such issue.

 

You could ask a local garage to check for leaks around the pump.

Thank you. That´s also what I think. I will get a uv leak detection kit. Im hoping that uv light make it easyer to see even a small leak or stains if it´s leaking from the waterpump. That´s probably the best way to go. 

I had the same coolant loss issue,was the egr cooler.Bought Mahle aftermarket part wich of course was an OE part just under half price.

You can check that pretty easy by removing the turbo pressure pipe to egr cooler,if you find a thick film of gunk inside the pipe wich is coolant mixed with exhaust gas that's it.

Thank you for the advice. I will check that as soon as I can 😀

4 hours ago, Nygaard said:

I will get a uv leak detection kit. Im hoping that uv light make it easyer to see even a small leak or stains

Some ay it shows up less with the already fluorescent coolant that VW uses, I have no idea about this, but if you have the dye, torch and glasses I would imagine it might still show up well enough.  You could also pressure test  to highlight things more.

 

Good luck.

 

1 hour ago, nta16 said:

Some ay it shows up less with the already fluorescent coolant that VW uses, I have no idea about this, but if you have the dye, torch and glasses I would imagine it might still show up well enough.  You could also pressure test  to highlight things more.

 

Good luck.

 

I did not know it they put fluorescent in the coolant.. 

Thank you all for your help here.

I have ordered pressure test tool and a uv leak detection kit. I will test it and check the EGR. I let you know how it goes

 

Thanks again 😀

1 hour ago, Nygaard said:

I did not know it they put fluorescent in the coolant.. 

No I don't know either, just what I saw someone put, I think they meant it might make the dye less easy to see but it was an old thread so I didn't ask - perhaps you will be able to tell us when you try.  Good luck.

 

10 hours ago, Nygaard said:

Thank you all for your help here.

I have ordered pressure test tool and a uv leak detection kit. I will test it and check the EGR. I let you know how it goes

 

Thanks again 😀

You can also pressure test the intercooler directly ,is very concludent.

Don't focus too much on testing the entire system at expansion tank...in many cases with a cold engine will hold pressure (1.2bar) over night and shows nothing.

 

My bet is on one of theese two ,egr cooler or intercooler

 

One more important thing...after each intervention the cooling system is very very hard to propperly bleed.In my case after replacing the egr cooler and bled with VCDS it took 10 days to settle the coolant level.I added every 2 days 100-150ml.I thought I had another leak but no

 

I have no idea with this engine but on my wife's car, despite some believing otherwise, you are supposed to pressure refill the coolant after a bigger drain but for this and other fluids proper road testing and use over a period of days gets the levels back which means perhaps a few small top ups as IulianE has already put.

 

I am experiencing exactly the same mysterious coolant loss (5mm drop in expansion tank after 3000km). I found it a year after the replacement of faulty water pump at 40k on a dashboard once I got low coolant warning light. 

Took the car to the dealer garage, they put the system under pressure but haven't found any visible leakage so they just topped the coolant and told me to monitor the level. Also, it seems that the water pump is working fine, it's totally new and was replaced in warranty with original part.

 

So in case it is EGR cooler leakage, could it be detected somehow outside the cooler?

 

@Nygaard did you manage to solve it?