Help Required Air-Con (C5-X7)

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Sloppysod
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Help Required Air-Con (C5-X7)

Post by Sloppysod »

Hi All,
Not sure if I have a problem or not......
I don't think my air-con is working............
Heater works, turn cabin temperature up, blower gets faster, car gets warm, turn temp down, fans slow down a bit car gets cold, but not as fast as it has done!
High pressure pipe under bonnet gets cold with engine running , therefore system is full, pump okay :-D

Now, could some one please, the next time they are in their car, carry out a test, turn the temp down and see if you get a cold blast, this must be done while air outside is <15 degrees? I am thinking as the outside temp is only just in double figures the car decides not to pass cold air-conditioned air into the car - am I right?

thanks in advance

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Sloppysod
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Re: Help Required Air-Con (C5-X7)

Post by Sloppysod »

Hi All, Just been out in the car, outside temp 14 degrees, inside.Blinking hot, Now, as I leave the car most of the time on Auto, I am sure it used to try to cool the inside down as quickly as it can........but it didn't!

Now I am thinking, Air-con fault even though as mentioned in previous post the pump runs and the pipe gets cold, is there anything else I can check...Electrics?.. before I get it checked out by a refridge engineer?

Other functions of heater work, so it is not the flaps or heater matrix.

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GiveMeABreak
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Re: Help Required Air-Con (C5-X7)

Post by GiveMeABreak »

The auto setting won’t necessarily go full blast to raise or lower the temperature with climate control. It varies speed according to ambient outside temp and the estimated internal temp of the car. On a hot day it even says in the manual to open the windows for the first few miles or so to help lower the temperature, as maxing out speed and temp won’t make any difference to the result necessarily - it will get to temp when it does, so Auto is recommended.

When did you last have the AC serviced Stu? When was it last vacuumed out and refilled?

You may be low on gas. I think ATS and Kwik Fit do an AC service for £59. Again, no charge if they can’t get it at least 10% cooler than it is.

Might be worth getting a cheap fridge thermometer and checking the temperature that it gets to on Auto with all flaps open and on lowest temp setting.

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Re: Help Required Air-Con (C5-X7)

Post by GiveMeABreak »

I'm in the car now doing a test as it is quite warm outside with my thermometer and will see how quickly she cools.

Readings shortly......

So update:
AC A.png
So car had been sitting in sun all day, unused.
Inside temp started at 30°C,
but then settled to 28°C on the thermometer before starting.

Outside Ambient temp on the display was 24°C.

Time Auto Climate was turned on was 15:40PM.
All settings turned to 'LO', with Auto setting on - all flaps opened.
AC C.png
At 15:45PM, 5 minutes later, the temp. on the thermometer
now shows 20°C. Note that the thermometer is placed
on the dash as shown and NOT directly
in the airflow on the windscreen vent.
AC D.png
At 15:50PM, the thermometer is now showing 4°C
5 minutes later, now a lot of heat has been displaced.
AC E.png
It continues to fall slightly
another 2 minutes later to about 4°C
AC F.png
Close up of thermometer. So test lasted 7 minutes
to get from 28°C internally to 4°C.
I suspect the top dash vent air helped the thermometer get to the 4°C a bit quicker.
But overall the cabin was cooled quite rapidly
for a car that was sat in the sun all day without being opened.

Not sure if this is of any help though Stu.

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Re: Help Required Air-Con (C5-X7)

Post by broomie »

I have a C5 X7 tourer and last year finally got the AC tested - it was leaking through the condenser so sopping it up would last days only - had condenser replaced all good now.

Paul

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Re: Help Required Air-Con (C5-X7)

Post by Sloppysod »

Cheers look forward to your report. As for service not in the 4 years I have owned it. I have used Kwikfit for air con on my wife's corsa so will pop down to see them over the weekend, if needed.

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Re: Help Required Air-Con (C5-X7)

Post by GiveMeABreak »

I updated my post and tidied the layout a bit Stu ^

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Sloppysod
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Re: Help Required Air-Con (C5-X7)

Post by Sloppysod »

GiveMeABreak wrote:
10 Apr 2019, 16:48
I updated my post and tidied the layout a bit Stu ^

yep, thank you for carrying out the test for me, good choice of music....
Alway, got into car tonight after leaving work, central display gave outside temperature as 23 degrees, started car and air-con started up as expected, medium speed fan. So my assumption is that the air conditioning output is determined by the outside temperature and not the cabin, therefore I think the functioning side of things is probably okay.

However,
Marc, you have set me a target, I know my system has never been as quick as yours, so it may definitely worth a trip to Kwik-fit for a recharge & clean.

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Re: Help Required Air-Con (C5-X7)

Post by GiveMeABreak »

Yes the gas does tend to ebb away a bit each year they say, despite being 'closed' system - as much as 10-15% a year - so always worth doing it every 2-3 years to keep it in tip top condition. You'll be amazed at how cool it is after a proper recharge (and assuming there are no actual leaks). Make sure you have the A/C running and the car is as cool as you can get it, because they are not supposed to charge you if they can't get it 10% cooler than what it is. :-D

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Re: Help Required Air-Con (C5-X7)

Post by JohnD »

I keep my X7 on auto - normally at 18C but if I find it too warm I press it down to a lower figure. One evening last Summer as I drove back from Dover, I'd turned the figure down and although it was blowing cold, every once in a while I felt a warm blast of air. I concluded that it was getting close to needing a refill. I have a Halford DIY kit which I used and it hasn't needed attention since then.

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Re: Help Required Air-Con (C5-X7)

Post by Sloppysod »

JohnD wrote:
10 Apr 2019, 21:02
I keep my X7 on auto - normally at 18C but if I find it too warm I press it down to a lower figure......................... I have a Halford DIY kit which I used and it hasn't needed attention since then.

I know these numbers are just numbers but 18! Keep mine around 21.5,😨.
Yes I have a Halford DIY gas cannister as the wife's car needs topping up every year or so. But taking a lead from Marc, and Google and as my car is over 8 years old and the A/C has never been touched, I think 'Evac & refill' may be the better option this time.

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Re: Help Required Air-Con (C5-X7)

Post by Sloppysod »

Hi All,
Well I followed the advice from Marc last month, paid my £59.95 to Kwik fit to get the Air-con regassed (see 2nd point), but I am still having problems.
The problem is that, I seem to remember the car would try to achieve the correct temperature as quick as possible, for example, if I got into the car on a hot day the fans would go full speed then slowly drop as the cabin cools down, or on a cold morning the opposite would happen, as such the fan speed would slowly increase, as the engine gets hotter, for a while until the cabin is warm, this does not seem to happen anymore. The only way I can get the car to adjust the fan speed to reach a different temp is setting the dial to either 'Hi' or 'Lo'.
Any ideas where to start looking, or am I just mis-remembering again. :roll:

2nd Point. I left my car with KwikFit and collected it later, even though it does seem to be a little better, I wonder if they actuall done anything, am I right that to fully regass the system and check the output they would have ha to run the engine for a while as I don't think they did!

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Re: Help Required Air-Con (C5-X7)

Post by GiveMeABreak »

On the second point Stu, I always stay with the car to make sure the monkeys do things properly (goes for tyre fitting too). :-D

When did you last change the Pollen Filter? If these are gunked up it can affect the system. As it's you. I will go and start the car that has been standing for a few days and stick it on Auto and report back.
On the A/C front, here is how the temps are calculated on the Dual zone system:

The passenger compartment temperature makes it possible, with the reference value displayed, to determine the temperature adjustment necessary to heat or cool the passenger compartment to the required value.

The passenger compartment temperature is calculated from the following elements:
  • External temperature sensor
  • Sun sensor
  • Air flow and distribution
The calculation depends on several parameters stored when the vehicle stopped, such as:
  • Exterior temperature
  • Calculated passenger compartment temperature
  • Day, date, time, second (this information makes it possible to calculate for how long the vehicle has been stationary)
On this vehicle, the passenger compartment temperature is not measured but calculated from a temperature assessment (Result of the sum of the power added and removed). This assessment is made for each zone.

During normal operation.
In the case of dual-zone air conditioning, the difference in reference value is taken into account in the regulation and the dual-zone actuator controls are calculated independently on the driver’s side and on the passenger’s side in order to reach the value required. In the case of the mono-zone actuators, such as the air blower, weighting is applied from the objectives calculated, giving priority to the driver.

Operation following a long period stationary:
  • Vehicle stationary for less than 5 hours; The interior and outside temperatures are stored when the vehicle is switched off. When the wake-up is triggered, the BSI determines the duration of immobilisation of the vehicle after receiving the information from the sunshine and outside temperature sensors. From this information, the air conditioning ECU estimates the passenger compartment temperature.
  • Vehicle stationary for more than 5 hours ; When the wake-up is triggered, the BSI determines the duration of immobilisation of the vehicle; After receiving the outside temperature, sunshine and blown air sensors information, a calculation estimates the passenger compartment temperature.
  • Following a short period stationary (Such as a stop at a motorway service station, for example).The air conditioning system re-starts at virtually the same point of operation as before the vehicle stopped. In 15 or 30 minutes, a passenger compartment does not vary significantly in temperate climates between 0 °C and 30 °C.
Whenever the battery is disconnected, the stored values are lost.

Modes:

"Auto Comfort" mode
When the windscreen demisting/de-icing control is deactivated, pressing the "AUTO" button switches the system to "Auto Comfort" mode.
In "Auto Comfort" mode, the automatic air conditioning system controls the distribution, mixing and air intake functions to maintain a comfortable temperature in the passenger compartment which is as close as possible to the temperature reference value selected by the occupants.
In "Auto Comfort" mode, the selections made by the automatic regulation concerning the distribution and the air flow are not displayed.
In "Auto Comfort" mode, the indicator lights on the air conditioning control and on the "Auto" mode control are lit continuously.
In "Auto Comfort" mode, the following parameters are used to control the temperature-related comfort:
  • Exterior temperature
  • Air quality
  • Engine coolant temperature
  • Level of sunshine
  • Vehicle speed
  • Temperature selection
  • Vehicle type ( estate - saloon)
  • Status of the sunroof shutter (Open - Closed)
  • Estimated passenger compartment temperature
  • Air conditioning parameters (Standard - Tropical)
In "Auto Comfort" mode, the passenger compartment air resistors are activated in relation to the engine coolant temperature and the temperature requirement.

"Auto Visibility" mode
Pressing the windscreen demisting/de-icing control switches the system to "Auto Visibility" mode.
In "Auto Visibility" mode, the automatic air conditioning system controls the distribution, mixing and air intake functions to quickly demist/de-ice the windscreen and improve the driver’s view.
In "Auto Visibility" mode, the selections made by the automatic regulation concerning the distribution and the air flow are not displayed.
In "Auto Visibility" mode, the indicator lights on the air conditioning control, the windscreen demisting/de-icing control and the "Auto" mode control are lit continuously.
The "Auto Visibility" mode is switched off by one of the following actions:
  • Pressing the windscreen demisting/de-icing control again
  • Pressing the "AUTO" button
  • Resuming manual control of the distribution
  • Modification of the air blower level
  • Pressing of the air conditioning button
Air intake function
  • In automatic mode, the air conditioning system can control partial or total air recirculation.
  • In automatic mode, the air conditioning system does not force the intake of exterior air at 100 %.
  • In automatic mode, if the passenger compartment air recirculation control is pressed, the AUTO mode is not deactivated, the control of the air intake alone is modified.

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Re: Help Required Air-Con (C5-X7)

Post by GiveMeABreak »

Stu AC A.png
Ok, so here today on the test it is 30°C outside the car.
Stu AC B.png
Stu AC C.png
It's 15:56 when I got in the car and switched the ignition on.
Temp. showing 29°C at 15:56.
Here's the Thermometer and the Display confirming times and temperatures before the engine is started.
Stu AC D.png
Stu AC E.png
I start the car and immediately set the temperature left and right to 14 °C and press AUTO on both controlsFan is running fast (not maximum) and all vents are open, including top diffuser.
3 Minutes later, temperature has rapidly reduced to 16°C on the thermometer.
Outside temperature is still showing a high of 27°C.
So important to note that you don't set it to LO or HI as these settings are not regulated as I mentioned in my last post. But fans will reduce in speed as temperature level is reached and maintained.

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Re: Help Required Air-Con (C5-X7)

Post by Estately »

Hi all,
Where else could you get so much detail on any C5 function?
Anyway we are currently in south east Spain and the first start of the day Sunday early afternoon saw the car register 35C some where and that dropped to 29C after leaving the doors and hatch open before driving for a 20 minute trip barely getting above 35mph given the nature of the road.
I have a temperature sensor that I can stick down the air vent and for interest did just that.
It got down to 7C with the internal fan blasting away before rising to 10C and the fans slowed down after about 10 minutes. We set the air con on auto usually to 22C.
Just to say before setting off from England, put a new pollen filter in and because of a failure of the fan motor module, that was replaced with a new BEHR module - eventually. The system was also regassed.
So the full blast scenario seems to be the norm on our small poll. Though I suspect that small differences in the fan resistor module specification would give different cooling traits.

(The Xantia external fans used to positively howl here on a hot and humid August night and the water pouring out underneath needed seeing to be believed. It always kept us comfortable even with an external ambient of 42C)

Out of interest Marc do you have any wise words on the air con recirculating.
What is the "A" in a circle as opposed to two circles and no "A"?
Would you normally drive with no recirculating showing? ( no A or circles showing on the display)
I seem to remember being advised to use recirc to get the internal temperature down more quickly.

Andy.