Air-con question

Nukumai

Question for those knowledgeable about air-con :

My wife gets about in a Lexus IS200 Auto which she has had since new (52 Reg / 60k miles). She had the ignition barrel replaced by Lexus back in October and has just told me that the air-con - which up to that point had worked flawlessly - wasn't working when she drove out of the dealership's workshop (yes, I know...!!)

Specifically, only when it is set at the lowest temperature will it provide chilled air, as expected. Other than that, it provides unpleasantly hot air. That is to say...the air-con does seem to function, but not as desired.

Is this symptomatic of a known issue (eg. a need for a re-gassing)? Or - as probabilities might suggest - could it be down to the Lexus dealership having temporarily removed upholstery beneath the steering wheel in order to replace the ignition barrel (thereby, maybe covering up a thermostat/sensor/controller etc.?)...or similar.

No biggie, but I ask in case this is a known symptom of an obvious fault. Either way, I will get it fixed.

Tiexen

Is it climate control (you set a temp) or just hot/cold?

Air con needs a regas every few years and also a an antibacterial clean to stop the damp smell you can get -

You also need to use a/c every month (even in winter) as it keeps the seals in good condition.

I think first step is a regas/clean of the system - this will tell you if its leaking gas.

cardinalbiggles

You do realise that air con doesn't just chill air right?

If you have your air con on and heater set anything other then minimum you will get warm (but dry) air from it.

Nukumai

Tiexen wrote: »

Is it climate control (you set a temp) or just hot/cold?

It's climate control.

Nukumai

cardinalbiggles wrote: »

You do realise that air con doesn't just chill air right?

If you have your air con on and heater set anything other then minimum you will get warm (but dry) air from it.

Please read my original question. This bit, perhaps :

"only when it is set at the lowest temperature will it provide chilled air, as expected. Other than that, it provides unpleasantly hot air."

forgotmyname

And below a set temperature. Its 5 degrees in mine aircon doesnt work.

It may light up, But it wont activate the clutch.

Nukumai

forgotmyname wrote: »

And below a set temperature. Its 5 degrees in mine aircon doesnt work.

It may light up, But it wont activate the clutch.

On my wife's car, for example, if the controller is moved above the lowest temperature setting ('16', from memory) there is an immediate shift from extremely chilled air to extremely hot air. It's binary.

Splott

Climate control doesn't bang out different temperatures of air. So if you set it to 23C it doesn't blast out 23C air. It blows out hot or cold and outputs that until the temperature is reached and then periodically to maintain it.

Some will mix colder air from outside to reduce the temperature being outputted but unless you're moving, it would only be hot air that was being outputted.

Also to get air from outside into the cabin it would need to pass through the pollen filter. A pollen filter should be changed every year or two years at the most. A blocked filter would prevent cold air being drawn in from outside and again, you only have hot air coming out. When was the last time the one in your wife's car was changed?

Paperbird

From your description of the problem it does sound like the interior temp sensor is the cause.
The sensor unit normally has a small fan in it pulling air from the interior so it could be the fan, the sensor or the wiring that is at fault,
The reason it blows cold when set to it's minimum is because on that setting 99% of climate controls will ignore any temp sensor signals from inside the car and blow the coldest air it can.

Nukumai

Splott wrote: »

Climate control doesn't bang out different temperatures of air. So if you set it to 23C it doesn't blast out 23C air.

No, I understand this. In my wife's case, the fact is that if the temperature controller in the car is moved fractionally from the lowest setting, chilled air immediately becomes very hot air. This is most definitely not what it is supposed to do.

Simple example, for illustration : if the ambient inside temp of the car is, say, 20 degrees and I set the controller to '16' (the lowest setting) the system will happily pump out chilled air as expected (that is to say, the aircon functionality does work). However, if I nudge the temp controller just a fraction above '16', very hot air is immediately distributed.

A hypothetical...if an aircon guy took a look and said to me that the problem is that the rotary climate controller mechanism is borked to the extent that the only "true" temp setting recognised is the lowest possible setting, and that any other selection is wrongly setting the desired temp to max heat...then that would logically explain my issue.

Splott wrote: »

A blocked filter would prevent cold air being drawn in from outside and again, you only have hot air coming out. When was the last time the one in your wife's car was changed?

I can't say for certain. What I do know is that the car has been meticulously and regularly (and expensively!) maintained by Lexus.

Nukumai

Paperbird wrote: »

From your description of the problem it does sound like the interior temp sensor is the cause.
The sensor unit normally has a small fan in it pulling air from the interior so it could be the fan, the sensor or the wiring that is at fault,
The reason it blows cold when set to it's minimum is because on that setting 99% of climate controls will ignore any temp sensor signals from inside the car and blow the coldest air it can.

Thanks. This sounds like a possibility. On a very similar note (as I mentioned in my previous post) I am also wondering if it could be as simple as the rotary temp selector on the dashboard (given that the problem surfaced immediately after Lexus had the upholstery beneath the steering wheel off to fix the ignition barrell).

Anyhows...I guess that I was hoping that somebody might say "hey, I have had that problem, and it was due to....". I think that I'm best just getting it sorted by Lexus.

Thanks!