Bleed valve on 1.6tdi

[DervMaster]

Hi all
I decided to change my antifreeze yesterday..now the problem being my heater is only blowing cool air after messing about for hours yesterday it's still the same🙃
Has the 2015 1.6tdi have a bleed valve anywhere? I've looked on rear matrix pipes off the bulkhead but can't see one 
 

I'm presuming it has a air lock as was fine before 

[Vahids]

Some people say it is possible to do the bleeding with VCDS.

 

 

[DervMaster]

I tried again yesterday emptied coolant and refilled..car is sitting at 90 on the temperature gauge and won't move past that Mark no matter what..the fan won't  kick in either..in the old days (😂)we used to rev the engine to get it up to desired temperature and when the fan kicks in then..its  job done..

My octavia has a limiter at 2500rpm😏

So it Won't get anywhere near the temp for fan to kick in even after I left it running for 2 hours..

 

One of the things I have noticed on draining the coolant their is no where near the manufacturers figure of 8litres draining out..an no where near going back in i woukd say ive out 3 litres back in resivoir and then doesn't drop in coolant tank..

 

So is their a air lock..hasn't the system fully drained after undoing bottom radiator hose...?

 

I'm left scratching my head now

 

Heaters were both fine before 

Passenger and drivers side 🙄

[DervMaster]

38 minutes ago, Vahids said:

Some people say it is possible to do the bleeding with VCDS.

 

 

Thanks..I've just read this 

[Ootohere]

Was the Heater set to cold before draining?

[Ecomatt]

Unless you did the coolant change when the coolant is warm enough for the thermostat to open, you will not get it all out.

OBDeleven and VCDS does have a bleed basic setting that activates all the pumps and gets rid of any air locks.

[DervMaster]

23 minutes ago, toot said:

Was the Heater set to cold before draining?

No it was working fine...so bloody annoying 

[DervMaster]

19 minutes ago, Ecomatt said:

Unless you did the coolant change when the coolant is warm enough for the thermostat to open, you will not get it all out.

OBDeleven and VCDS does have a bleed basic setting that activates all the pumps and gets rid of any air locks.

Im unable to access any software atm..so if I get car warm again upto 90degrees..then empty and 

Refill perhaps?

[Vahids]

The proper way of filling is Using a coolant suction refill kit which get rid of any air pocket in the system.

https://ffx.co.uk/product/Get/Draper-Cav1-5010559095445-Expert-Universal-Cooling-System-Vacuum-Purge-And-Refill-Kit

 

[DervMaster]

Just a quick update

The car has been back to dealer 

And Had

new matrix 

Coolant flush

Coolant motor (whatever that is)

New header tank

 

 

Got the car back... And guess what

 

The heater is absolutely terrible now (blows cold)I would say even worse..

No warm air at all out of the air vents even after doing over a hour or so journey with heaters on full an full heat...even the same turned down to half and under 

 

Very annoying 

Not losing coolant.

No warning lights on dash

Car is driving perfect just no heating 

[J.R.]

On 11/12/2022 at 12:49, DervMaster said:

.car is sitting at 90 on the temperature gauge and won't move past that Mark no matter what..the fan won't  kick in either..in the old days (😂)we used to rev the engine to get it up to desired temperature and when the fan kicks in then..its  job done..

The old days are no longer, 90°c is the engines operating temperature and the thermostat will be maintaining that, the fans wont cut in unless it overheats which at this time of year is unlikely to happen even under load on the road let alone idling in a garage.

 

Cooling systems these days do what they say on the tin, well that is until the Silkat teabag bursts and a dealer starts extracting money out of you.

[ApertureS]

On 11/12/2022 at 12:07, toot said:

Was the Heater set to cold before draining?

Wouldnt make any difference, the coolant flow isnt changed by setting the heater to cold.

 

 

 

New diesel engines are so thermally efficient that they struggle to overheat, coolant doesnt need to work nearly as hard to regulate the temperature - so to sort this out the engine uses a shrouded water pump, multiple coolant circuits and many electric water pumps. You need to run a set bleed routine on the car using odis which will activate all pumps, open all valves and allow the coolant to flow correctly. Failure to do it this way results in either air locks and over heating, or air locks and no heating in the cabin.

 

They are so thermally efficient that youd struggle to overheat a tdi with it just idling. Hence when water pumps seize, people only notice it under extreme load such as hills, or towing. 

 

FYI: The coolant purge routine is called Venting the coolant system high and low pressure circuits. 

[SuperbTWM]

Have you confirmed the auxiliary coolant pump is operational?

[DervMaster]

I honestly couldn't tell you...im letting the garage sort it out..it will have to go back to them...

I could do with VCDS to see if the motor flaps are all working correctly.. if anyone knows where to get it from these days..mine is about 15yrs old an doesn't work

 

Not sure if the garage would plug it into anything like VCDS to do a in depth real time scan

[PetrolDave]

On 31/12/2022 at 18:44, DervMaster said:

I could do with VCDS to see if the motor flaps are all working correctly.. if anyone knows where to get it from these days..mine is about 15yrs old an doesn't work

Ross-Tech Distributor List

[DervMaster]

So after a few months now and several visits to dealer My car is now sorted it seems so I thought  I would  share with  you all what they changed  and how it's  now given me back hot air heating equally on both driver and passenger side.

 

Heater matrix flushed twice with new coolant (better but still luke warm on drivers side)

 

New expansion tank (silicone bag split in old one causing  heater matrix blockage)

 

New wager pump as apparently switch was faulty? 

Had car back and  after 1 week drivers side heater went cold  🙄 (really noticeable on cold mornings)

 

Went back and now had a new EGR cooler valve and hooray this seems to have cured the problem 👏🏻

 after doing  400miles this weekend the heaters both passenger and drivers side are blowing equal amounts of  hot air 

 

So hopefully this lasts an now all seems ok 

 

What a absolute nightmare trying to get this sorted but tbf the dealer have been great an replaced it all under warranty and  given me a courtesy car each time my car wenr back in for repair / diagnosis 

 

Only one thing ive noticed my coolant has now gone brown and not the nice orange colour it should be after 3 flushes and having the EGR cooler valave fitted (it was before having the EGR cooler fitted though )

[SuperbTWM]

The EGR cooler is in the same circuit as the heater matrix so it stands to reason that the silica bag split blocking it up will indeed result in poor heater performance. 

 

Not sure why the coolant would go brown unless it has been contaminated by something in the process of having the work done, or maybe the lack of egr coolant flow caused the coolant to become 'burnt', after all its cooling 600+C exhaust gasses at times.

 

Glad you got to the bottom of your woes.

 

 

[fr1nklyn]

Brown means "rust" usually. Or maybe just the expansion tank is old and/or a bit dirty and changes the color of the coolant   

 

Take a some coolant out and see it's actual color.

 

From another forum:
 

Quote

 

it only looks orange if you shine a light from the top looking down on the coolant but if you take a sample out it looks straight pink.

 

source: https://www.audiworld.com/forums/a8-s8-d3-platform-discussion-60/orange-coolant-just-fyi-2939621/