Airconditioning gas leack on W205? aircon Evaporator Coil Fix (uncool air conditioning) ? dashboard must be removed ?

[benzw205]

Thank you so much for your help !

Since first post I was not always near the car and had no time to check more, but I should do something now.

I refilled gaz once already but now after few months air is not cold anymore.

Benz stealer said to replace the evaporator (if correct, I mean the part behind the dashboad, the most complicated to change), which I won't do before getting more opinions.

1. Did it work just fine and slowly over time become less efficient ? ===> YES, and back to normal after gas refill
2. have you had it professionally re charged and serviced.? ===> just charged once
3. have you replaced the cabin/pollen filter ? ===> YES, always on schedule at stealer
4. how old is the car and how many miles on it ? ===> 6 years, one of the first batch launched in Germany, almost 100000 kms

 

[benzw205]

Ok, so I used a gas leak detector and it seems that the leak is really around the evaporator coil.
Is there really nothing else to try but remove the dash completely to change the coil ?
I might prefer to refill few times a year until I decide to change it if the only solution is to remove the dashboard.

 

[MrGreedy]

My understanding is:

You could be losing PAG oil from the leak in the evaporator which could damage the compressor (I mentioned this just a couple of posts ago), unless you can rule this out.

It is against the law to knowingly release refrigerant into the atmosphere.

Released refrigerant is really bad for the environment.

 

[benzw205]

My understanding is:

You could be losing PAG oil from the leak in the evaporator which could damage the compressor (I mentioned this just a couple of posts ago), unless you can rule this out.

It is against the law to knowingly release refrigerant into the atmosphere.

Released refrigerant is really bad for the environment.

Thank you, but oil is mixed with gas, right ? so when refilling it will add more oil with the gas ?

 

[benzw205]

A 205 seems quite young for an evaporator leak. Our 124 is off to PCS on Monday for a new evaporator but its 26 years old. Big job and it will probably be there all week. Its had a small loss for 3 years or so but recently got worse. A regas would only last 3 weeks rather than 12 months and you could smell the gas in the cabin after recharging it. Pressure tests etc showed nothing. It was confirmed using some sort of electronic sniffing device that detected gas coming out of the dash vents.

same here, they used a gas sniffer, but it seems that gas in the cabin is not really a danger.

 

[benzw205]

By the way, do you know if when evaporator coil has a leak, compressor oil could also leak from the evaporator ? As it seems that oil is mixed with gas in the system ?
Or maybe most oil will remain in the compressor and can hardly leak from the system ?
If oil can leak from the evaporator coil, should I find oil under the car when parked ?
thanks again !

 

[Petrol Pete]

OK I would never normally recommend or use any of the 'magic potion' A/C seal liquids that are available ....unless the cost of repair was going to be prohibitive . Example : I have just done some A/C work on my wife's 2004 Zafira , if my A/C guy had said there was a leak in the evaporator I would have risked a shot of 'stop leak' goop rather than spending a load of money on a car that is worth very little . If it worked , bonus , if not I would at least have given it a shot.

Thank you, but oil is mixed with gas, right ? so when refilling it will add more oil with the gas ?

The DIY top up bottles tend to be just refrigerant so every time you top up with them the PAG to refrigerant ratio becomes less = less lubricant for the compressor = damaged compressor. For example if a system was completely empty and it was filled solely by using DIY bottles there would be virtually no lubrication for the compressor.

 

[Petrol Pete]

By the way, do you know if when evaporator coil has a leak, compressor oil could also leak from the evaporator ? As it seems that oil is mixed with gas in the system ?
Or maybe most oil will remain in the compressor and can hardly leak from the system ?
If oil can leak from the evaporator coil, should I find oil under the car when parked ?
thanks again !

There is often about 100/150ml of oil in the system of most cars , spotting a leak will (obviously) depend on where the evaporator is located . On some cars its in the cabin and in some it's in the engine bay very near the passenger area. and under high pressure 150ml is not much but if you can actually get to the evaporator you can usually see evidence of a leak...by which time it's too late you have spent a ton of time/money getting to it so may as well replace it.

 

[benzw205]

OK I would never normally recommend or use any of the 'magic potion' A/C seal liquids that are available ....unless the cost of repair was going to be prohibitive . Example : I have just done some A/C work on my wife's 2004 Zafira , if my A/C guy had said there was a leak in the evaporator I would have risked a shot of 'stop leak' goop rather than spending a load of money on a car that is worth very little . If it worked , bonus , if not I would at least have given it a shot.

The DIY top up bottles tend to be just refrigerant so every time you top up with them the PAG to refrigerant ratio becomes less = less lubricant for the compressor = damaged compressor. For example if a system was completely empty and it was filled solely by using DIY bottles there would be virtually no lubrication for the compressor.

Thank you, but why oil would leave the compressor where it should remain ?

and if oil was leaking, I think that I should find it somewhere under the car when parked ?

 

[benzw205]

There is often about 100/150ml of oil in the system of most cars , spotting a leak will (obviously) depend on where the evaporator is located . On some cars its in the cabin and in some it's in the engine bay very near the passenger area. and under high pressure 150ml is not much but if you can actually get to the evaporator you can usually see evidence of a leak...by which time it's too late you have spent a ton of time/money getting to it so may as well replace it.

Isn't it the W205 C class forum here ? So it seems that we are talking about the class 2014 - 2021.

The evaporator is as in most cars behind the dashboard so it's a very brutal job to change it, and impossible to see a leak, only a sniffer can find it.

Is it possible that the leak is at the entrance and exit of the evaporator (I guess that there is a joint?), but the coil actually still be ok ? But because we have already removed the dash, better just replace the whole system ?

Thank you.

 

[Petrol Pete]

It travels around the system 'mixed' with the refrigerant which goes from liquid to gas and back again as it goes through the thermal cycle under pressure. Are you thinking the compressor has it's own little gearbox filled with PAG oil ? maybe that is the confusion here. The PAG oil is flowing through the system.

 

[Petrol Pete]

The gas has only one way in and out of the evaporator and that is through the Expansion valve .

 

[GP801]

This is what the evaporator looked like when it was removed. It ha probably taken 3 years to get this bad. Initially it needed an re-gas after 12 months, then 6 and finally it lasted around 3 weeks. I was advised the only reason to try the magic leak cure solution was to give a quick solution for trading it in! Some said they had been successful with the magic liquid but most advised against it.

 

[benzw205]

This is what the evaporator looked like when it was removed. It ha probably taken 3 years to get this bad. Initially it needed an re-gas after 12 months, then 6 and finally it lasted around 3 weeks. I was advised the only reason to try the magic leak cure solution was to give a quick solution for trading it in! Some said they had been successful with the magic liquid but most advised against it.

hello, it seems that oil leaked from the evaporator together with gas ?

 

[alabbasi]

Deleted - repetitive