A3 8V No Heat Diagnosis

[Sid2020]

If your not getting high engine temps and the system is getting hot I would think your pump is working

[cliffcoggin]

Chris.

If you manage to get the heater unblocked, or if you have to replace it, consider what caused it to become blocked initially. It's possible there is a burst bag of silica gel that will give you another blockage.

See this for an explanation of a problem that I only recently became aware of:

https://www.youtube.com/watch?v=39ngHGvMzEg

 

[Chris777]

Hi Cliff

Thanks for your input

I came across the burst /leaking silica bag suggestion. Only some 8V got them apparently and if was present says on side of header tank. Thankfully looks like mine never had one. It is a copart rebuild front damage, the coolant temp sensor had somehow dislodged and all coolant out when I got it. Not sure if impact somehow dislodged but can find no other leak or damage to why the coolant came out. I have read the matrix can gum up if left sitting without coolant for a while (money was maybe 6 weeks max) hoping it's just a flush. Looking at the coolant carefully that came out couple tiny bits of plastic in it so also slight concern where from and if more stuck anywhere

[Sid2020]

Finding out what VAG cars got the bag is  almost impossible, I’ve never came across any service document that states what vin numbers they were introduced from which also means we don’t know what vehicles were affected. The logic behind the bags makes sense from a VAG  standpoint, they have to allow for all regions of the world  where maybe service procedures are not followed so a few blocked heater matrix’s is better then engines failing  due to corroded engine internals. A pain in the !Removed! but still better then skimming engine heads and blocks

[Chris777]

Hi Matt.

It says 'Mit Silikat' on side of header tank if has one apparently. Mine doesn't have this so presuming it didn't have in first place.

[Sid2020]

Unfortunately it wasnt printed on every reservoir that it was fitted in but this may be year dependent. Shining a torch thru the empty reservoir bottle while looking inside is a good way of checking for one also if in doubt. 
below photo is from a T6 with nothing on bottle as a idea where to look 

[Chris777]

What am I looking at in the pic sorry?

 

[Sid2020]

8 minutes ago, Chris777 said:

What am I looking at in the pic sorry?

 

Thats a bag circled. That’s where the bags are sometimes found on bottles without mit silikat printed on them 

[Chris777]

Got you, I've had a good look and can't see one or the remnants of one

[Chris777]

Hi guys

When flushing out should I run up to let thermostat open before taking bottom pipe off?

Just thinking to try and get as much out as poss but then If I do and then cool when I vacuum refill will that mean more poss places for air blocks again?

[Sid2020]

7 minutes ago, Chris777 said:

Hi guys

When flushing out should I run up to let thermostat open before taking bottom pipe off?

Just thinking to try and get as much out as poss but then If I do and then cool when I vacuum refill will that mean more poss places for air blocks again?

Won’t do any harm

[Sid2020]

Just now, Sid2020 said:

Won’t do any harm

A vacuum refill should fill both sides of the thermostat with possibly a small bit of trapped air but nothing major 

[Chris777]

Thanks Matt

[Chris777]

Afternoon 

Hope had nice weekend. Mine has been fighting the !Removed! coolant lines off the water pump as getting to the ports of the matrix next to the fire wall with that !Removed! heat shield is a reet ****. Decided to disconnect as next join as didn't want snap the matrix port as you warned . Finally got off pump. The lower pipe was full of lovely fresh coolant but the top looked gunked up and crusty. Pic below. Is the top one the inlet to the matrix or the other way round? Does all this muck look like matrix block / bad maintenance or likely lead to having to replace pump?

Got too cold so had to abandon but all ready to now try and flush. Just wanted get your thoughts so far 

[Stevey Y]

14 minutes ago, Chris777 said:

Afternoon 

Hope had nice weekend. Mine has been fighting the !Removed! coolant lines off the water pump as getting to the ports of the matrix next to the fire wall with that !Removed! heat shield is a reet ****. Decided to disconnect as next join as didn't want snap the matrix port as you warned . Finally got off pump. The lower pipe was full of lovely fresh coolant but the top looked gunked up and crusty. Pic below. Is the top one the inlet to the matrix or the other way round? Does all this muck look like matrix block / bad maintenance or likely lead to having to replace pump?

Got too cold so had to abandon but all ready to now try and flush. Just wanted get your thoughts so far 

Hi are you positive that is the pump?, it looks like a thermostat housing with the two bypass ports, [smaller bore pipes], the main pump is run by the cam belt, but the gunge definitely looks normal as most people dont bother to change the antifreeze at regular intervals or just top it up with tap water which is full of calcium.

Steve.

[Chris777]

 hi mate

Thanks for reply, no not certain at all am a complete newbie at this. I though the water pump and start housing all came as one? Those 2 pipes I've taken off that lead to the matrix do they go onto the bypass ports then sorry? Am I OK using these to flush / backflush the matrix as can get off from port right up against the fire wall.

thanks for your help

[Sid2020]

I believe what I’m seeing is the combined water pump and thermostat but hard to tell from the picture. The crud could also be from a additive that someone has added to seal a leak

[Sid2020]

These are from a A1 1.4 tfsi that I did a few weeks ago so if any of it looks familiar then this is what you may also have