Heating anomaly

[NickFletcher]

Hi all,

 

When I turn the heat up high or all the way to HI I get hot air blowing on the passenger side but only continued cool (exterior temp?) air on the driver's side. Any of you wiser heads have thoughts about what to do next?

 

Many thanks,

 

Nick

[ords]

Try this first.

 

[paulski]

It is very probable that your heater matrix is blocked, as these are very typical symptoms.

 

I myself have suffered this, my car is still cooler on drivers side (I get cold hands in winter driving unless I close the vents down,) as not had matrix replaced as yet.

 

it occurred after routine cambelt and water pump drain down.  silica in the expansion tank depositing in the matrix (or the bag leaked before this) 

 

 

 

[NickFletcher]

Thanks Ords, thanks Paulski

[RaoulE]

What about hot air blowing out of the outside vents (so driver and passenger side) but the 2 inner vents are still blowing relatively cold air? According to garage x this is normal behavior, and they did an AC flap test/reset (did it myself as well with OBD11). No fault codes. Can anyone confirm that this is normal behavior for the AC on AUTO? Thank you!

[SC03OTT]

Lol, no. No it’s not normal behaviour. 

[paulski]

Heated water enters the matrix and exits from the passenger side. Hence you get heat on one side only as the blockages seem stop water flowing to the driver's side of the matrix. 

 

I've not seen issues with only hot air at farthest vents on the forum. There are certainly temperature sensors to control cabin split temperatures and these will modulate the flap valves I think. 

 

Edited 24 October, 2023 by paulski

[Moribund]

Hi, 

For a few months I have not been getting hit air only on the drivers side of my Octavia. After a service I was told that my coolant was contaminated- I’ve attached a picture of a sample from the header tank and it looks ok to me. 
I have the double wall coolant tank (see photo )but I can’t see any sign on the bag of silica ? Nor could I see any silica beads in the water sample?

 

I’ve booked the car into a local garage who specialises in German cars but I’ve read some horror stories about repair bills of a thousand pounds (to flush the system and replace the heat matrix ). If this is the case I’m tempted to sell and replace the car - I already have two pending repairs which I can’t afford.

Has anyone got any experience of similar heating problems? 

[NickFletcher]

Hi Moribund,

 

I'm embarrassed to admit that my problem was in fact my own ignorance. My old Octavia only had one temperature dial and the new one has temperature control on the left and on the right. Everything else was a red herring. Apologies if this doesn't solve your problem.

 

All the best,

 

Nick

[TalibanTed]

2 hours ago, Moribund said:

Hi, 

For a few months I have not been getting hit air only on the drivers side of my Octavia. After a service I was told that my coolant was contaminated- I’ve attached a picture of a sample from the header tank and it looks ok to me. 
I have the double wall coolant tank (see photo )but I can’t see any sign on the bag of silica ? Nor could I see any silica beads in the water sample?

 

I’ve booked the car into a local garage who specialises in German cars but I’ve read some horror stories about repair bills of a thousand pounds (to flush the system and replace the heat matrix ). If this is the case I’m tempted to sell and replace the car - I already have two pending repairs which I can’t afford.

Has anyone got any experience of similar heating problems? 

 

The sample looks to have rust in it? If it's true, I've read in a few places that the engine block rusts from inside the waterways and that blocks the matrix along with the silica if the bag bursts.

 

I may have a go at replacing the matrix in mine, doesn't look too bad a job, although I have a mechanic friend who's quoted me fairly cheap for it. But, it's most definitely the wrong time of year for this! I replaced my expansion tank and the old one definitely doesn't have a silica bag in it any more so I know it's burst...the replacement absolutely does though so that'll be removed too!

[Moribund]

On 30/11/2023 at 17:59, TalibanTed said:

 

The sample looks to have rust in it? If it's true, I've read in a few places that the engine block rusts from inside the waterways and that blocks the matrix along with the silica if the bag bursts.

 

I may have a go at replacing the matrix in mine, doesn't look too bad a job, although I have a mechanic friend who's quoted me fairly cheap for it. But, it's most definitely the wrong time of year for this! I replaced my expansion tank and the old one definitely doesn't have a silica bag in it any more so I know it's burst...the replacement absolutely does though so that'll be removed too!

Thanks Ted,

 

I had noticed those particles and it could be rust. The car is going into the garage on the 18th and I’ve sent these photos with information about the silica bag issue - I’m sure he’s aware of this already if he deals with German cars.

 

i hope it’s something straight forward- if it comes to a grand and a half I’m tempted to sell the car. I’ve got a few other issues: boot won’t open with central locking, washers packed up, position p error on gears and it’s only done 41000 miles

 

i hope your replacement goes smoothly- there’s a few You Tube videos showing you what to do but I’m **** at even the simplest car maintenance jobs. How did you know that your original tank had a bag in the first place - did you see the beads in the coolant?

[paulski]

@Moribund

 

My coolant was that colour sort of rusty, but I never saw silica granules in it, it's odd for sure that it discolours. 

 

 I had the coolant flushed out twice but alas,  the matrix is still cold on drivers side, once blocked with silica beads,  it ain't going to come out as the pipes are very thin and cannot be unblocked. 

 

I reckon a good indy garage would do the matrix for 3-4 hours labour plus parts. 

 

Coolant drained,

remove glove box

remove heater blower

remove matrix. 

install new matrix

reinstall removed parts 

refill with new coolant and bleed. 

 

 

[Moribund]

On 02/12/2023 at 18:20, paulski said:

@Moribund

 

My coolant was that colour sort of rusty, but I never saw silica granules in it, it's odd for sure that it discolours. 

 

 I had the coolant flushed out twice but alas,  the matrix is still cold on drivers side, once blocked with silica beads,  it ain't going to come out as the pipes are very thin and cannot be unblocked. 

 

I reckon a good indy garage would do the matrix for 3-4 hours labour plus parts. 

 

Coolant drained,

remove glove box

remove heater blower

remove matrix. 

install new matrix

reinstall removed parts 

refill with new coolant and bleed. 

 

 

Thanks Paulski

 

Did you get yours replaced in the end or were you seeing if the flush did the job?

 

The matrix part isn’t that expensive- I’ve seen them ranging from 50 to £100. Three to four hours labour- I’m not sure what that would cost. I imagine the independent garages vary depending on where you are in the country.

 

The only additional step I may request is to replace the coolant tank if there is a silica bag (as I said I can’t see one but it makes sense to do this for prevention)

[paulski]

Not had matrix replaced as yet and have lived with it for over two years now, I leave the driver vents shut😃, and then allow the warmer passenger side to warm the cabin, it's tolerable as I'm on the south coast and its not really cold for very long periods generally. 

 

The garage flushed the coolant twice, but alas it made little difference. 

 

Yes part isn't high cost, labour as you say varies where you are, so difficult to determine that cost. 

 

 

[TalibanTed]

On 01/12/2023 at 18:15, Moribund said:

Thanks Ted,

 

I had noticed those particles and it could be rust. The car is going into the garage on the 18th and I’ve sent these photos with information about the silica bag issue - I’m sure he’s aware of this already if he deals with German cars.

 

i hope it’s something straight forward- if it comes to a grand and a half I’m tempted to sell the car. I’ve got a few other issues: boot won’t open with central locking, washers packed up, position p error on gears and it’s only done 41000 miles

 

i hope your replacement goes smoothly- there’s a few You Tube videos showing you what to do but I’m **** at even the simplest car maintenance jobs. How did you know that your original tank had a bag in the first place - did you see the beads in the coolant?

 

The tank has Silikat printed on it, but there's no bag in it any more. Once they burst the contents will go straight through the cooling system.

 

Quoted £600 to replace the matrix and flush from an indy likely using the cheapest parts, but a friend of mine has said he can do it for £250 all in with approved parts and a likely 2-3 hour flush. He also has to contribute a bit to use the garage he work at for private jobs which I don't mind. I'll have a look tomorrow at how difficult it is to get to, then decide whether to try it myself or not 🤣

[paulski]

I had the coolant expansion tank replaced and its no longer coming with the bag in it nor a double walled version with silica in a section of it. it does not have Mit Silikat printed on the outside either. 

 

Part number for the expansion tank was 5Q0121407M. 

Edited 8 December, 2023 by paulski

[Moribund]

Did you end up having to have the matrix replaced or did the flushes and expansion tank replacement do the job?

[varaderoguy]

oh goodness - I hope this wasn't the silicon from the coolant expansion tank that has burst.  That would block up your heater matrix and its an arse to take out and clean it up.

[Moribund]

Finally got round to taking my car in to an independent (but German car specialist) garage. It was confirmed that it was the heat matrix that was causing the heating problem and I was quoted £700 parts and labour to flush , replace the matrix and replace the header coolant tank. Not sure if that is a reasonable price but he says he would need it for 2 days and can’t do until the New Year 

[Moribund]

Had a trip to the dealers this morning and got a comparison quote. I can see why people on here call them the stealers…they said it would normally be £1800 but they would do a special deal for £1600 - literally more than twice what the Indy garage quoted. I know they will use Skoda parts but in this case the parts are not that expensive -you’re paying for the labour. £1800 would just less than a quarter of the value of the car

[Paws4Thot]

21 minutes ago, Moribund said:

-you’re paying for the labour

... and the new car showroom.

[paulski]

Dealer will be likely to take the dashboard out as per workshop manual to access the heater matrix. However it's possible to do without removing the whole dash, hence the massively difference in price! 

[J.R.]

No they wont, the mechanics are on a bonus for doing jobs quicker than the book time, the customer gets billed for the inflated book time and the garage and mechanic rub their hands together.

[Moribund]

Finally took the car into the garage last week to have this work done. Garage flushed the system and replaced the heating core and header tank (with no silicat bag). I noticed a massive difference in the heater from the moment I collected the car.

Went for a long business trip (well 250 miles) and on the return trip a warning for low coolant appeared. I topped it up at the next services (this was Friday evening). I then did another hour’s motorway driving. Drove the car locally on the Saturday and Sunday morning started the car and the same warning again. In both cases the car needed topping up by about a quarter of a pint.

 

Is this normal or should I contact the garage to check for leaks? Heating is now working fine but this is annoying. Any advice would be greatly appreciated 

[TheClient]

2 hours ago, Moribund said:

Finally took the car into the garage last week to have this work done. Garage flushed the system and replaced the heating core and header tank (with no silicat bag). I noticed a massive difference in the heater from the moment I collected the car.

Went for a long business trip (well 250 miles) and on the return trip a warning for low coolant appeared. I topped it up at the next services (this was Friday evening). I then did another hour’s motorway driving. Drove the car locally on the Saturday and Sunday morning started the car and the same warning again. In both cases the car needed topping up by about a quarter of a pint.

 

Is this normal or should I contact the garage to check for leaks? Heating is now working fine but this is annoying. Any advice would be greatly appreciated 

I'd say for anyone diy ing it without a vacuum fill it's very normal to have some air pockets.

 

If they vacuum filled and test drove it up to temp, it shouldn't really happen but i suppose it can as they are prone to some air pockets.

 

This is assuming there is no leak from their reassembly. It might be hard to spot if there is one. But you could check rad hoses and matrix hoses on the engine side. You won't be able to see under dash but could check for wet carpet. 

 

also, you shouldn't keep filling up with only water as you will dilute the coolant so may need to add half what you've added neat. Ideally you should use demineralised or distilled water as well. 

 

If you can spare time maybe worth calling them and arranging to check for leaks and add the neat coolant for the water added.