Hi, I hope someone can help, i have a 2017 Superb Estate, 2.0 150 Manual.

 

The drivers side blows cold, really cold - even when set to max heat nothing! The passenger side blows hot without issue.

 

When the issue first came up i had the matrix (one of 2 i believe) replaced, it cured it for a while then went cold again - so i had it flushed out, "suspicious crap" of unknown origin was flushed and it worked again for about 6 hours of my 8.5 hour journey the following day, then at 2am went stone cold again.

 

We are at a loss as the the cause or solution, flushing seems to temporarily work, my mechanic wont fit a filter as if it blocks it could trash the ending due to no cooling (although I would see that with the temp rising) - please help. At this stage ive spent into the thousands and come to no solution, its miserable to drive in cold weather as there is zero heat from drivers side through any vent.

Can anyone suggest a cause and solution or even provide schematics for the systems involved so i can do digging myself (i'm no mechanic but i did once build a car). Thankyou

A filter on the inlet to the matrix would not do any harm. if it choked up it would have the same effect as the matrix choking. No heat but no engine overheating. It sounds like the whole coolant system needs drained, flushed and possibly even a biocide run through it.

I don’t understand why these cooling system issues happen on some units and not others? 🤷🏻

I’m only guessing here, but isn’t there normally a flap buried near the center console which moves from cold to hot?

The fact it’s just the drivers side makes me think something is up with the HVAC side of things.

 

Try looking for flap adjustments for a Skoda and plug it in and do a scan (if you haven’t already), I guess you’d be able to force a calibration in vcds too.

 

I might be talking rubbish but ya never know 

 

Edit: 

look at the comment by tommi, fingers crossed 

 

Was there a lot of dark-coloured debris produced during these cooling system flushes? If so, check the expansion tank - is it marked on the side 'Mit Silikat, and is the coolant in it discoloured?

VW originally fitted a small bag of silicate granules into these tanks, these bags are prone to fail and allow the contents to migrate (and block) small water passages, EG. matrix cores.

Do a search on the forum under 'Tea Bag, Silikat' etc.

There is a possibility that your silicate bag has failed - if this is the case, the expansion tank should be replaced with one without the 'tea bag' before flushing the system again, you may get lucky.   

Edited 16 December, 20223 yr by Warrior193
missing text

As per Warrior193 above, the plastic bag containing "silicate" granules has failed emptying its contents into the cooling system. Common on 2.0l diesel engines of a certain vintage with coolant tank having "Mit Silikat" printed on it.

 

A search on Briskoda and other forums will reveal the extent of damage that results, blocked matrix and radiators. Extremely difficult to flush out, often at great cost when requiring a host of parts changing.

 

Iirc some members successfully got Skoda to repair for little cost under goodwill, if you shout loud and long enough.

 

Wouldn’t a blocked heater matrix result in heat reduction on both sides of the car, not just the drivers side? 

Thankyou all, I discovered the "mit silicat" issue after posting this. My garage insists he has never seen this but the header is being replaced and reading the symptoms i'm certain this is the issue.

5 hours ago, numskull said:

Wouldn’t a blocked heater matrix result in heat reduction on both sides of the car, not just the drivers side? 

Yeah would be surprised if the silicate issue resolves one side and not the other unless there are different matrices for different sides?

7 minutes ago, travs said:

Yeah would be surprised if the silicate issue resolves one side and not the other unless there are different matrices for different sides?

Pretty sure I've read this one-sided heat loss as a symptom of the silikat matrix blockage several times on here.

Maybe the structure and connections of the matrix are such that when it starts to block up, one lateral side is more affected than the other.

17 hours ago, Danoid said:

Edit: 

 

Top man Danoid!, just tried this on my Superb and have now got heat & fan back in the footwells again. 

5 hours ago, Gammyleg said:

Top man Danoid!, just tried this on my Superb and have now got heat & fan back in the footwells again. 

Woohoo, free easy fix, result

To OP, recommend that you check the expansion tank anyway, it could save you some grief in the future. Very simple and low cost DIY.