No heat/cold air in 2018 Golf

[Magpie1862]

My 2018 Golf 2.0 Diesel GT has a problem with the air con.

In the summer, the cold air setting doesn't do anything so I have to wind the windows down.
In the winter, the warm air setting does nothing.

The very good independent VW garage I use, say it needs a new water pump, timing chain and the heater matrix replacing/.
I am not a technical person so don't know why all that needs doing.

The water pump/timing chain were only replaced 2 years ago.

They say re-gassing the air con will sort out the cold air but not the warm air issue.

Estimated cost of all the work £1,500.

I am reluctant to spend that amount on a 7 year old Golf but as the weather is getting colder, don't really want to have to wear gloves and 3 jumpers when driving.

Any ideas on what the actual root cause could be ?

Thank you

[NotNormal]

No heat is quite possibly because the heater matrix is blocked by the cilica beads that have come out the stupid bag that VW/Audi group stick in the header tank. Is a very common problem and I had to do this job on my wife’s 2017 S3 earlier in the year.

When your matrix is replaced make sure you take the bag out, and leave it out, to save it happening again in the future.

[stevemcs]

See if you canr get the temp reading of the heater pipes going into the matrix, if its hot going in cold coming out then its likely blocked.

If the engine gets up to temp then i don't think it can be the water pump, again yoou can feel the hoses.

WE have also had the odd issue where the AC has messed with the cabin heater.

[Magpie1862]

NotNormal said:

No heat is quite possibly because the heater matrix is blocked by the cilica beads that have come out the stupid bag that VW/Audi group stick in the header tank. Is a very common problem and I had to do this job on my wife s 2017 S3 earlier in the year.

When your matrix is replaced make sure you take the bag out, and leave it out, to save it happening again in the future.

I got another garage to remove the silica bag about 3 years ago for that very reason so can't seeing being that, unless it was already blocked.

Many thanks

[Magpie1862]

stevemcs said:

See if you canr get the temp reading of the heater pipes going into the matrix, if its hot going in cold coming out then its likely blocked.

If the engine gets up to temp then i don't think it can be the water pump, again yoou can feel the hoses.

WE have also had the odd issue where the AC has messed with the cabin heater.

Thanks Steve.

I am not mechanically minded enough to do this. I put fuel in and monitor tyre pressure.

I might have to bite the bullet and just get it fixed. £1,500 is better than say £20k for a new car.

I will ask the garage if they can just check the matrix for blockages, IF you can do that without having to remove the water pump/timing chain.
I don't know what is connected to what. The garage did say it is a labour intensive job, hence the cost.

[mattvanders]

I had my heater matrix go on my Audi tt last year, as much as heated seats are great having an actual heater to clear the windscreen properly on colder days is even more important. Worth getting the system draining out a few times to ensure it is full clear and won’t clog up the new heater matrix.

[stevemcs]

Magpie1862 said:

Thanks Steve.

I am not mechanically minded enough to do this. I put fuel in and monitor tyre pressure.

I might have to bite the bullet and just get it fixed. £1,500 is better than say £20k for a new car.

I will ask the garage if they can just check the matrix for blockages, IF you can do that without having to remove the water pump/timing chain.
I don't know what is connected to what. The garage did say it is a labour intensive job, hence the cost.

You don t need to be, open the bonnet, at the back will be 2 pipes that go through the bulkhead, one goes in, the other comes out, see if they both feel warm.

Under the dashboard, passenger side you will see a radiator, again one in, one out these are fed by the pipes at the back of the engine, if it s blocked the one going in will be hot, the one coming out cold - it can be very hot though so be careful

To change the heater matrix on a golf is a bit easier than the a3 as less trim needs to be removed, we allow 2-3 hours for this so around £400.

The blend motors can also fail - I haven t seen this on a golf but on a transporter, that s usually a dashboard out job.

We have a golf in tomorrow I ll see if I can get a picture, failing that I ll get one of my superb Which I think is the same.

Edited by stevemcs on Tuesday 18th November 19:08

[Magpie1862]

Thanks very much