Air Con issue when on idle.

[stratosg]

Hi Kodiaq friends.

 

I have a colleague of mine that bought a brand new 2.0TDi 150Ps 4X4 DSG Kodiaq three months ago  which is an amazing car but as temperatures in Greece are already above 30C they need their A/C to work in order to coo down the cabin. And here comes the problem.

 

When the car is idle and the A/C in on there is no cold air coming from the vents. As soon as it starts moving the A/C works as should brinking cold air. Then a red light occurs and ta-dah hot air again. Green light and the air turns cold again.

 

The car has been to the dealer's, where no fault popped up at the diagnostics. The cooling gas found to be Ok within the circuit BUT the fan behind the refrigerator was not turning in any case. Thus they replaced the fan and the fan's control unit. But no luck. The A/C works the same annoying way. Today we moved the car at a road with no traffic and lifted the bonnet. Then My colleague drove the car so slowly that I was walking by the car and looking at the Fan. While there was cold coming out from the vents, the fan behind the refrigerator did not work. When we stopped the car, the cold air turned to just ambient air.

 

Any ideas of what the issue can be?

 

Thanks in advance for yout inputs.

 

P.S. For your interest, in my Roomster as soon as I activate the A/C the fan starts to work. Same happens to two VW Golfs (1.4Tsi Gt and 1.6Fsi respectively) and in one OPEL (Vauxhaul) Astra 1.4 petrol.

Edited 19 June, 2019 by stratosg

[fuzzz]

If I'm not mistaken there should be two ventilators bigger and smaller ...both must working like crazy on these condition. I had similar problem on my 2014 superb...both ventilators were replaced....bigger one sends signal to smaller ventilator etc...

[silver1011]

1 hour ago, stratosg said:

Then a red light occurs and ta-dah hot air again. Green light and the air turns cold again.

 

Where are these red and green lights?

[Guest]

34 minutes ago, silver1011 said:

 

Where are these red and green lights?

 

[silver1011]

Ah, I thought he was getting warning lights on the dash 

[stratosg]

14 hours ago, fuzzz said:

If I'm not mistaken there should be two ventilators bigger and smaller ...both must working like crazy on these condition. I had similar problem on my 2014 superb...both ventilators were replaced....bigger one sends signal to smaller ventilator etc...

 

The car has one fan only which does not work under any circumstances. My Roomster has also one fan but as soon as I press the A/C button it spins like hell and the car sounds like a small ship. The two VW Golfs have the dual fan system and they both spin like crazy.

 

It is supposed the dealer replaced  that fan alongside with its control module.

Edited 20 June, 2019 by stratosg

[stratosg]

12 hours ago, silver1011 said:

Ah, I thought he was getting warning lights on the dash 

 

Please be kind towards me, as I am a Greek living in Greece and the English is not my mother tongue, so errors, mistakes and all kind of **** may occur. I must improve my English language skills because It seems that my English sounds Greek to you. 😅😅

[fuzzz]

2 hours ago, stratosg said:

 

The car has one fan only which does not work under any circumstances. My Roomster has also one fan but as soon as I press the A/C button it spins like hell and the car sounds like a small ship. The two VW Golfs have the dual fan system and they both spin like crazy.

 

It is supposed the dealer replaced  that fan alongside with its control module.

Oh my bad yes just lookd under the bonnet and yes on fan...remember dealer said if I want tow bar from factory then there will be two fans to cool engine...but that not the case. Case is dealer have to chnage hole unit.

[olderman1]

Whilst probably nothing to do with OPs problem, I had a problem in my previous car with the A/C cutting out when the outside temp got hot. Whilst the dealer could find no fault, some advice I was given at the time was to switch on the air recirculation in the car, so the A/C then draws air that is already cooled rather than sucking in air from outside that is constantly hot.

[stratosg]

8 hours ago, fuzzz said:

Oh my bad yes just lookd under the bonnet and yes on fan...remember dealer said if I want tow bar from factory then there will be two fans to cool engine...but that not the case. Case is dealer have to chnage hole unit.

 

By saying "hole unit" what exactly do you mean? As the fan unit have been already replaced then the a/c compressor is the next step ?

[Kenny R]

You’ve not got eco mode selected for the climate, or drive mode?

Edited 20 June, 2019 by Kenny R

[stratosg]

14 hours ago, Kenny R said:

You’ve not got eco mode selected for the climate, or drive mode?

Ooops ! I have no idea, the car is not mine. I clearly remember not having Eco mode selected on the climate unit, but I have no idea about the drive mode. I will ask and let you know.

[ChristianScout190]

It's the condenser fan not kicking in. 

 

Compressor compresses the refrigerant vapour to a state of highly compressed vapour, 

This high pressure vapour passes through the condenser (coil, radiator etc) and gives its heat to the surrounding air - either by the motion of the car or by a fan. 

As the heat is withdrawn from the refrigerant it condenses into a high pressure liquid. 

This liquid is passed through an orifice which meters the flow into the cold but... Or evaporator. 

The pressure in the evaporator is kept low by the compressor removing refrigerant. The liquid suddenly finds itself at a lower pressure and will boil off into vapour, absorbing heat from the airflow across the evaporator. 

And the cycle repeats..... 

 

No fan = no liquid = no cold air. 

 

I guess the red light is the system shutting down due to excess g pressure on the high pressure side. 

 

[stratosg]

On 21/06/2019 at 19:30, ChristianScout190 said:

....

 

I guess the red light is the system shutting down due to excess g pressure on the high pressure side. 

 

 

This is a well written explanation of how the a/c system works. As you correctly mentioned the condenser fan is not working. BUT this unit is supposedly replaced by the dealer and the new part does not work either.

 

So there are two possible situations. Either the dealer is a plain liar or the new unit is broken so my collegue's lack is from another tale.

 

The red light is just a red triffic light. Nothing in the car.

 

@Kenny R Neither the climatronic nor the engine is switched to ECON mode.

Edited 24 June, 2019 by stratosg
spelling error correction

[ChristianScout190]

The condenser fan will be controlled from a high pressure signal - either a standard on/off pressure switch or more likely a pressure transducer. 

The dealer needs to physically check the system pressure  and compare to the tmreadings from the ecu/bcm

[skomaz]

I think you will find that this is how the A/C is supposed to work - it's similar on my Suzuki - and is a fuel saving thing connected to the stop / start system.

 

Whilst the engine is running and the car moving the compressor works and you get cold air.  However, when you stop and it idles or the stop/start system kicks in the compressor disconnects / stops to save fuel and the vents switch to recirculation mode, without cooling the air.  Once you set off again the compressor re-connects and you get cold air and the vents switch to bring in outside air.  The only time this can be over-ridden in my Suzuki is when the front demister is on or when the internal ambient temperature rises again and gets too high (in which case the engine restarts and the compressor kicks in again).

 

Try checking in the manual and seeing if the system in the Kodiaq operates is the same way.

[DaveMiller]

Hi Skomaz.  The system certainly won't be cooling if the engine stops (as the compressor is no longer being driven!), but in my Kodiaq (and every airconned car I've had since 1976), the aircon still cools at idle.

 

To enable that, the idle speed is often a little higher with the aircon on, and (at least in the Kodiaq) the stop-start system will be disabled if there's a reasonable cooling load for the aircon to be dealing with.  The OP talks about a car trying to deal with the 30-degree temperatures in Greece, so that sounds like a reasonable cooling load!

[stratosg]

23 hours ago, ChristianScout190 said:

The condenser fan will be controlled from a high pressure signal - either a standard on/off pressure switch or more likely a pressure transducer. 

The dealer needs to physically check the system pressure  and compare to the tmreadings from the ecu/bcm

 

I suppose that dealer should know this operation sequence and my colleague should not provide technical knowledge to them, but gain knowledge from them. The car is due to new visit at dealer's at Friday, so time will tell.

 

22 hours ago, skomaz said:

I think you will find that this is how the A/C is supposed to work - it's similar on my Suzuki - and is a fuel saving thing connected to the stop / start system.

 

Whilst the engine is running and the car moving the compressor works and you get cold air.  However, when you stop and it idles or the stop/start system kicks in the compressor disconnects / stops to save fuel and the vents switch to recirculation mode, without cooling the air.  Once you set off again the compressor re-connects and you get cold air and the vents switch to bring in outside air.  The only time this can be over-ridden in my Suzuki is when the front demister is on or when the internal ambient temperature rises again and gets too high (in which case the engine restarts and the compressor kicks in again).

 

Try checking in the manual and seeing if the system in the Kodiaq operates is the same way.

 

A non operational A/C unit during the stop time of start/stop mode is absolutely normal, but disengaging the A/C compressor while idleing is something new to me and t be honest it is a kind of stupidity. Imagine being at a traffic jam at 14:00 under 38 degrees centigrade.

 

21 hours ago, DaveMiller said:

Hi Skomaz.  The system certainly won't be cooling if the engine stops (as the compressor is no longer being driven!), but in my Kodiaq (and every airconned car I've had since 1976), the aircon still cools at idle.

 

To enable that, the idle speed is often a little higher with the aircon on, and (at least in the Kodiaq) the stop-start system will be disabled if there's a reasonable cooling load for the aircon to be dealing with.  The OP talks about a car trying to deal with the 30-degree temperatures in Greece, so that sounds like a reasonable cooling load!

 

We tested his Kodiaq at work. We started up the engine and let the car settle down the revs as she performed a cold start, then we pressed the A/C button to turn the compressor on. The engine raised her revs as should and the instant fuel consumption raised a ca. +0.2 as should but no cold air produced. Then my colleague drove the car with the bonnet open in a speed that I was able to walk by the car and inspect the radiator fan. You can understand that this is a ridiculous speed. The fan did not spin but the air came stone cold from the vents. Then he applied his brakes and set the car to idle. Ta dah... No cold air instantly. And currently ambient temperatures during daytime are between 30 and 37 degrees.

 

[Guest]

1 hour ago, stratosg said:

We tested his Kodiaq at work. We started up the engine and let the car settle down the revs as she performed a cold start, then we pressed the A/C button to turn the compressor on. The engine raised her revs as should and the instant fuel consumption raised a ca. +0.2 as should but no cold air produced. Then my colleague drove the car with the bonnet open in a speed that I was able to walk by the car and inspect the radiator fan. You can understand that this is a ridiculous speed. The fan did not spin but the air came stone cold from the vents. Then he applied his brakes and set the car to idle. Ta dah... No cold air instantly. And currently ambient temperatures during daytime are between 30 and 37 degrees.

 

Record doing this on a mobile and show it to the dealership. 

 

Get yourself something similar to the item below and record what it is showing while conducting  the above. 

 

https://www.halfords.com/motoring/engine-oils-fluids/air-con/air-conditioning-test-thermometer

[stratosg]

5 hours ago, Fin69 said:

Record doing this on a mobile and show it to the dealership. 

 

Get yourself something similar to the item below and record what it is showing while conducting  the above. 

 

https://www.halfords.com/motoring/engine-oils-fluids/air-con/air-conditioning-test-thermometer

 

Dealer has a good knowledge of the problem. He just cannot fix it. He tested the car for an hour and as I mentioned before he already replaced the refrigerator's fan and control unit. Still nothing. Now my colleague is waiting for his next appointment to see what the next steps will be.

 

Now I have to deal with that nasty stinky smell on my a/c unit. I guess some disinfectant and a new cabin filter but I do not know if I have to spray some wurth, sonax, liqui moly etc disinfectant (with hose) or a dettol from the outside of the car and from the inside from cabin's filter housing. Yet the major problem I am facing is my back as it is week #4 I am in terrible pain due to a lumbago.

[stratosg]

Problem Solved.

 

Dealer decided to use his multimeter to found out that the connector plug was problematic. So the connector from car's side replaced and everything works fine now. It was simpler than anyone would expect.

 

And I am keep saying to my students always to follow the K.I.S.S. (Keep It Simple Stupid)  paradigm when solving a problem.

 

My colleague wants me to give you a great thanks for helping us solving his problem with your inputs. And of course I would like to thank you for your help, I was pretty sure about Briskoda spirit.

Edited 29 June, 2019 by stratosg