Leon Heating Only Working On Passenger Side

cuthound

Active Member
Jan 26, 2024
50
27
Should it be consistent? I thought surely the bubble would just be filled out by the coolant?

Does the system need to be bled and then filled up properly?
Not sure about your 1.6Tdi engine, but the Cupra engines require a specific bleeding sequence with valves operated by OBD11 manually to properly achieve this.
 

vixonss

Active Member
Mar 6, 2024
26
4
Not sure about your 1.6Tdi engine, but the Cupra engines require a specific bleeding sequence with valves operated by OBD11 manually to properly achieve this.
Ahh i see my uncle probably didnt do this if it is the same process. I can take it to a garage and have them do it, but if that isnt the fix its just a waste of 40 pounds
 

vixonss

Active Member
Mar 6, 2024
26
4
So my uncle thinks it’s the water pump just from the description of what we’ve told him, even though it had been replaced 9k miles ago.

I also have an error code on the vehicle which (may) be the problem however, this codes been here since december and this problem has only just recently started.

Error code: P190E00 - coolant pump for charge pressure cooler supply voltage.

If anyone thinks this is the cause opinions would be appreciated!
 

SuperV8

Active Member
May 30, 2019
1,545
685
So my uncle thinks it’s the water pump just from the description of what we’ve told him, even though it had been replaced 9k miles ago.

I also have an error code on the vehicle which (may) be the problem however, this codes been here since december and this problem has only just recently started.

Error code: P190E00 - coolant pump for charge pressure cooler supply voltage.

If anyone thinks this is the cause opinions would be appreciated!
You have 3x coolant pumps!
The main belt driven pump (electro-mechanical - with an electrically actuated shroud to help speed up engine warm up), and 2x electric pumps.
The Charge pressure pump from your fault code is one of these small electric pumps.
This is on a separate low temperature circuit down behind the radiator (just 'topped up' by the main circuit) - compared to the main pump and the EGR/heater matrix micro circuit.

If you can hear gurgling, that is air in the system, but is it an air lock which was there since the heater matrix change - or from recently loosing some coolant?
That will be why you aren't getting good heat into the cabin.
Have you lost the coolant again since topping up last time?
Were the rear hoses behind the engine disturbed during the heater matrix change? As those were leaking as in the first video I shared.
 

vixonss

Active Member
Mar 6, 2024
26
4
You have 3x coolant pumps!
The main belt driven pump (electro-mechanical - with an electrically actuated shroud to help speed up engine warm up), and 2x electric pumps.
The Charge pressure pump from your fault code is one of these small electric pumps.
This is on a separate low temperature circuit down behind the radiator (just 'topped up' by the main circuit) - compared to the main pump and the EGR/heater matrix micro circuit.

If you can hear gurgling, that is air in the system, but is it an air lock which was there since the heater matrix change - or from recently loosing some coolant?
That will be why you aren't getting good heat into the cabin.
Have you lost the coolant again since topping up last time?
Were the rear hoses behind the engine disturbed during the heater matrix change? As those were leaking as in the first video I shared.
After inspection over the weekend everything seems to be within working order.

Coolant seems to be holding fine.

I believe when i bought the car the water pump had been replaced at 161k and the coolant wasn't flushed properly after reading you need VCDS for this to open specific places to let all the coolant bleed.

Then when my uncle changed the matrix the same thing happened with no VCDS being used.

Could this cause the air pocket I seem to have.

I am thinking of booking it in with Halfords tomorrow for them to do a coolant change on it as I assume they'll use VCDS just want a second opinion on if I'm on the right track with no VCDS used causing the issue with old coolant in the system and air pockets.

What do you think could this be the fix?
 

SuperV8

Active Member
May 30, 2019
1,545
685
So the coolant level appears stable and the heating is fully working?

The TDI has a complicated cooling system, with 3x circuits, 2x high temp and 1x low temp, 3x pumps and one way valves - and the official flushing procedure includes blocking off 2x circuits while you flush the remaining 1, then do the same for the other circuits. Then it's supposed to be vacuum filled.
I would be looking for a VAG specialist to do this.
Just dropping the lower radiator hose will only exchange part of the coolant, and as someone on here noted they found a lot of sediment in the thermostat housing when they had that changed.
You are also supposed to purge the cooling system via diagnostics after a cooling system flush - not sure Halfords would do this. The cooling system will eventually self bleed if you don't but it wouldn't be good to have an air pocket in any sensitive part.
 

vixonss

Active Member
Mar 6, 2024
26
4
Well to add insult to injury. My thrust bearing has now started to break down so on top of the already pressing issue this one takes priority.

Any ideas of how much a replacement would cost part + labour.

Thanks!
 

SuperV8

Active Member
May 30, 2019
1,545
685
I presume you mean your clutch release bearing? and not your crank thrust bearing :eek:

The clutch release bearing isn't expensive - (part number = 04L105269) but its a gearbox out job.
While 'you're' in there you would be best to also fit a new clutch.
 
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