General No Aircon- suspect leaking Evaporator coil / Cooling coil.

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General No Aircon- suspect leaking Evaporator coil / Cooling coil.

swatchlu

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Hi, my car has an aircon gas leaked and the initial suspect is the evaporator. There are no visible leak around high pressure pipes, low pressure pipes and the condenser.
Compressor is working, blower fan is OK.

Anyone know how to change the evaporator coil, that is behind the dashboard?
DO we need to remove the dashboard in order to access the evaporator? How about steering wheel?

I was told, evaporator coil is usually the prime suspect when there is no visible leak around the system.

thanks
 
You can find the leak using a UV dye. Visit a shop and they will find it quickly. Sometimes it's very hard without it.
No point to start removing things.

I've never seen a leaking evaporator on Grande btw...
 
Even with UV dye and a uv light it can be almost impossible to find a leak.

Over what period has the gas leaked out? If it's not been serviced for years it can naturally drop the pressure over time.

First look at getting it regassed they will do a vacuum and hold and this will highlight if there are any leaks in the system, then take it from there.

Usually the last thing to need replacement is the evaporator as its tucked up nice and cosy in the cabin, the condenser is always suspect number 1
 
thank you for your advice. The workshop here do not use dye, they use torchlight and visual inspection, and I know it is not as reliable. But that is how the workshops work here.

The 1st time the gas leaked was 2 months back, and the leak came from the high pressure hose, I got that replaced and everything was fine. The 1st week of Jan, I experienced no aircon. I went to check and the pressure was low, the work shop top it up and they couldnt find any visual leak.
After 6 days there is no aircon again and the pressure was low. The workshop told me the most common cause is the evaporator coil.

I cannot see any visual leak from the condenser, and around the pipes (high pressure / low pressure)
 
Hi,
The fluid in the aircon system is an invisible gas at room temperature and pressure so you can't see it. There is also a small quantity of oil. It is very difficult to spot leaks without adding dye to the system as the gas leaves no marks and most engine bays have at least some oil around. Can you take the car to another aircon shop for a second opinion?

Robert G8RPI
 
Thanks for your advice. Yup I went for a 2nd workshop and they did a simple test, using a burner and a rubber hose. Any leaking the burner will turn blue flame to green. It is a very primitive way, this is Asia. :-(.

They conclude the evaporator coil is leaking and require change.

I am a pretty handson person and I would like to try taking out the dashboard myself. Is it worth the effort?
1) Do I need to remove the steering wheel or I can lower the whole steering column down?
2) Do I need any computer (multiecuscan) setting if I remove the steering wheel?

thanks,
 
I can't answer your question about taking the dashboard out, but you can remove and replace the steering wheel without any computer re-settting. Just disconnect the battrey for about half an hour first to make sure the airbags are not going to deploy.

However, I too would be amazed if the problem was the evaporator. They are so well protected that there should be no reason for them not to last the life of the car. You can buy electronic "sniffers" that detect aircon refrigerant. You turn the heater fan on and poke the sniffer probe into one of the face vents and see if it beeps.
 
I would suspect condenser as well, Often you will see oily stain marks near the leak where the lubricant has been exposed to road dust.
 
Check again, seriously. Dashboard removal is not a pretty job.

You can see the evaporator from the air filter if I remember correctly. (well you can't put your head there but you can use a camera + uv light + dye)

Make sure the system is full of gas/dye, work the a/c for some days and then check again.
 
Just to reiterate, the evaporator very rarely leaks, there are no stresses on it, no environmental contaminants or corrosive chemicals near it and it's kept tucked up inside the car.

The condenser on the other hand sits at the front of the car, is exposed to all manor of grit, dirt, stones, rain and chemicals off the road.

If there is enough gas leaking out to change the colour of a burner flame then there is enough gas leaking out to hear the leak....


If the gas is able to change the colour of the flame then (though I'm not 100% in this) it implies your car has been filled with the wrong refrigerant gas as r134a (the correct gas) is a HFC and shouldn't contain any chlorine which is what burns green.

The wrong gas could have destroyed the seals all round the system so it could be leaking from everywhere.

Until you've found some aircon people who know what they are doing I wouldn't get too far into removing the dash
 
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Actually the evaporator coil is right in front of the air filter. Maybe you can removing the lower parts of the dash without meddling with the top part? I'm not sure as I've never tried, only thing I knew was that my fingers could touch the coil when installing the filter.
 
I agree that condenser vs evaporator coil, condenser should be the one that go first as it is exposed to harsher environment. 3 workshops that I approached told me the the evaporator coil is the culprit. And usually when that is replaced, the problem is solved. My 1.4L 8V GP is 8.5 yrs.

I have seen my friend's GP condenser leaking, at the joint, there is a green oily stain. And my friend feedback that his aircon is not as cold as before. He got that joint sealed up by welding and it solved the problem.

Have done a re gas and vacuum, it last about 5 days. 2 days ago, I went to a workshop, they gas it, try to find the leak and less than 24 hours there is no more cold air. :-(
I agree that removing the dashboard is a tough DIY job, there are a lot of things to take out. I attempted last night and after 2 hours, I only managed to remove the central console (radio, dial buttons, odometer and blower fan).

There are 3 torx nuts (left centre right) lying far end of the dashboard and is hindered by the wind screen, the space is tight. I trying to figure out how to remove it.

Steering wheel - can I lower the whole steering wheel column instead of remove the wheel?
 
Yes, you should be able to lower the complete steering wheel and column assembly, but I'm not sure the wires to the stalks will reach so you will have to disconnect those.
 
First look at getting it regassed they will do a vacuum and hold and this will highlight if there are any leaks in the system, then take it from there.

Usually the last thing to need replacement is the evaporator as its tucked up nice and cosy in the cabin, the condenser is always suspect number 1


Found this old thread when researching..

My 07 mj GP has poor aircon. :eek:

MultiECUScan cuts the compressor in ok..
Engine OFF

..and tells me the SYSTEM pressure is @4.1

All with a car thats been parked..cold.. for 24 hours


is the pressure ..at a little over 4 ..
far too low?
 
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MultiECUScan cuts the compressor in ok..
Engine OFF

..and tells me the SYSTEM pressure is @4.1

All with a car thats been parked..cold.. for 24 hours


is the pressure ..at a little over 4 ..
far too low?

I bought a GP in Dec 19

After poor aircon for 16 months.. I hot around to a regas (£36)

The day after.. I plugged in MES

SYSTEMPRESSURE : 4.3 BAR

check atmospheric pressure ..950mbar

System pressure again : 4.33 / 4.39

Run engine climps steadily.. after 1 minute I turn off engine

Falls away from 20.0 bar

These are reference numbers I can keep an eye on :)
 
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