C5 Aircon Problem Re-visited

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Hi Dear,

I can't stand the heat with a failing aircon in this hot and humid country.
Currently, the car have to go above 2K RPM in order to have aircon coming out from the vents during the day. I will be loosing aircon when the car is stuck in the traffic or moving at low speed. On a hot day with temperature exceeding 32C, the car is like an oven. At night, the aircon will work fine (temperature below 29C), crazy isn't it?

Earlier, some have advised to look at the flap motor buried within the dashboard. I can't find any mechanic who are willing to do the job.
A mechanic (a friend of mine) here run some sorts of an aircon tester and point to me that the aircon is no good and in the red zone with 60 mark. 40 being ideal. He advised that the only way to resolve this is to change the aircon compressor. Since he promised to me that he will have the problem resolved if I changed to a new compressor, I have no other option but to give it a try by investing in a new compressor. I will be driving the car for just another year but I am running mad in a C5 year 2007 with a lousy aircon.

Will update all again once I have my aircon compressor replaced this coming weekend.

Thank you very much.

Regards,

[Hell Razor5543]

There are a couple of things I would check first. Does the car read the outside temperature correctly? (if it does not that would cause it issues). When was the last time the aircon was re-gassed. Even the best vehicle aircon suffers from micro-leaks. Most European garages recommend the aircon is re-gassed every 2 years or so.

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There are a couple of things I would check first. Does the car read the outside temperature correctly? (if it does not that would cause it issues). When was the last time the aircon was re-gassed. Even the best vehicle aircon suffers from micro-leaks. Most European garages recommend the aircon is re-gassed every 2 years or so.

Yes, done the re-gas several times every few months but to no success. A few times of aircon refresh procedure is equal to the cost of a compressor here.

One thing puzzled me is why would the aircon be cold only below 29C as shown on the dashboard? The hotter the weather, the weaker is the aircon. Can't understand the logic.
I used to set the aircon temperature manually from 23, 21 and now I have to set at 18 to have cold air coming out.

I really hope by changing the compressor will eradicate the problem once and for all.

Regards,

[vborovic]

The hotter the weather, the weaker is the aircon. Can't understand the logic.

Actually, that is logical, if it is the compressor ... the external temperature puts extra stress on it to produce cooler air, the same "stress" applies to home/office air-cones as well ... the air-con working in 50-60°C is basically on it's technical limit (usual models at least)

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The hotter the weather, the weaker is the aircon. Can't understand the logic.

Actually, that is logical, if it is the compressor ... the external temperature puts extra stress on it to produce cooler air, the same "stress" applies to home/office air-cones as well ... the air-con working in 50-60°C is basically on it's technical limit (usual models at least)

I see. Thank you very much for the input.
Hence, you also agreed that the compressor is failing too.

Regards,

[Hell Razor5543]

I recall somebody having an issue with their aircon, and the external temperature sensor was wildly inaccurate (about 30 degrees out!). As a result, the aircon control system was also way out. However, when a replacement sensor was fitted (and it was accurate) the aircon system was then able to function correctly.

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I recall somebody having an issue with their aircon, and the external temperature sensor was wildly inaccurate (about 30 degrees out!). As a result, the aircon control system was also way out. However, when a replacement sensor was fitted (and it was accurate) the aircon system was then able to function correctly.

Thank you very much for sharing the information.
May I know where exactly is this sensor in C5?

Regards,

[Hell Razor5543]

On my C5 (which is a MK1) it is under the left wing mirror (little dome). However, if your car has a temperature readout on the dashboard (mine has, on the top centre display) see what it says. If it is close, then the sensor is not likely to be at fault. However, if it is out, this could explain the aircon issue, as the same sensor is used for the display and the 'ambient' side of the aircon.

[SaabC5]

Have you had the system dye tested for leaks? You say you've regassed every couple of months, that really shouldn't be neccessary. If your temp sensor on the wing mirror is reading low the system won't try so hard to reduce the temperature inside because it thinks its pretty cool already. Best way to check whether its working is to compare a thermometer side by side with the info display temperature reading to see if they agree. If they are wildly out your sensor is fubar'd.

[Hell Razor5543]

I have just checked, and the stock code for the temperature sensor is 6445 F9, and may well be on the right hand mirror.

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Dear all,

My C5 has finally been fitted with the new compressor and the air-con is back to normal working condition. This is certainly worth the investment.

Thank you very much to all for the kind advice and information.

Regards,

[GiveMeABreak]

Now you can really chill out!

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Now you can really chill out!

Hi there,

You're right man . Am very happy with the long lost chill.
The next on the list will be the Engine Mounting, still have not gathered all the parts number in order to place an order .

Regards,