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

[benzw205]

Airconditioning gas leak on W205?​

hello, has anybody removed the dashboard to access the evaporator coil ? And do you confirm that it can leak, or from where else the aircon gas could leak ?

thank you.

 

[Jobsworth]

Evaporator leaks are rare. Not completely unheard of, but rare. Condensor leaks are the most common - it lives in a harsh environment, with stone chips, road salt, dirt and leaf mould all playing a part. Compressor faults are the second most common, moving parts and seals that can and do fail. Have you had it diagnosed as the evaporator?

 

[benzw205]

Evaporator leaks are rare. Not completely unheard of, but rare. Condensor leaks are the most common - it lives in a harsh environment, with stone chips, road salt, dirt and leaf mould all playing a part. Compressor faults are the second most common, moving parts and seals that can and do fail. Have you had it diagnosed as the evaporator?

Dealer told me to replace the evaporator coil, but I don't know how he can find the leak without removing dashboard console? Maybe just a guess, so I am trying to know more about the possible causes.


Thank you.

 

[MrGreedy]

Worth watching this. It's for a range rover, but you get the idea:

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I think I remember he said that if you have an evaporator leak, then you would be able to detect PAG oil on the carpets (or in the AC drain system/outlet).
Worth asking for a second opinion on diagnosing the leak before going to that trouble.
A regas (not necessarily with refridgerant) and UV dye would leave tell tale signs.

 

[GP801]

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.

 

[benzw205]

hello, what else could it be if not evaporator leak ?
We should not have to refill any aircon gas in a correct system.

 

[JHS]

hello, what else could it be if not evaporator leak ?
We should not have to refill any aircon gas in a correct system.

See post #2 above........or take the dealers word for it.

 

[benzw205]

Evaporator leaks are rare. Not completely unheard of, but rare. Condensor leaks are the most common - it lives in a harsh environment, with stone chips, road salt, dirt and leaf mould all playing a part. Compressor faults are the second most common, moving parts and seals that can and do fail. Have you had it diagnosed as the evaporator?

Can you please tell me the difference between condensor and evaporator ?
I see only a compressor and an evaporator coil in any air conditionning system.

 

[Trickythemerc]

Basic science is one evaporates and the other condenses.

 

[alabbasi]

You insert a sniffer in the vent which will detect refrigerant. If they were able to detect it, then yes it's the evaporator and yes, you can't get to it without removing the dash.

 

[benzw205]

Basic science is one evaporates and the other condenses.

Thank you, I understand now.

 

[benzw205]

You insert a sniffer in the vent which will detect refrigerant. If they were able to detect it, then yes it's the evaporator and yes, you can't get to it without removing the dash.

Thank you, so only the evaporator is a real problem to change.

and if no refrigerant gas in the vent, it means that the problem is the condenser in front of the car ?

 

[alabbasi]

Thank you, so only the evaporator is a real problem to change.

and if no refrigerant gas in the vent, it means that the problem is the condenser in front of the car ?

If elsewhere, it should be easy to identify with leak dye, soapy water or some other method

Thx

 

[GP801]

If you are not confident of the dealer diagnosis then get a second opinion from an AC specialist. There are plenty about. The evaporator is by far the worst item to replace. Our 124 is now back and fully sorted. Roughly 15 hours labour to complete the job - a couple of other minor issues were found unrelated to the AC once it was all taken apart.

 

[alabbasi]

I expect that the job would not be as hard as a W124. They built cars differently back then.

 

[benzw205]

If you are not confident of the dealer diagnosis then get a second opinion from an AC specialist. There are plenty about. The evaporator is by far the worst item to replace. Our 124 is now back and fully sorted. Roughly 15 hours labour to complete the job - a couple of other minor issues were found unrelated to the AC once it was all taken apart.

yes, the cheater from stealer just said to change the evaporator, but how could they know without removing the dashboard ?

 

[SMS]

You can smell R134 a/c gas in the car or use a gas sniffer, you can also check the evaporator drains for dye if it’s been added to the system. Replaced a few now and heater matrixes.

 

[benzw205]

You can smell R134 a/c gas in the car or use a gas sniffer, you can also check the evaporator drains for dye if it’s been added to the system. Replaced a few now and heater matrixes.

Hello,

What is weird is that the stealer didn't do this to tell me that there is a leak...

And do you know if it's bad to use aircon with low gaz level ?

Thank you.

 

[MrGreedy]

The general advice on here is get a specialist to look at this properly. Have you done that and if so, what did they say?

We can speculate all day, but it needs someone to look at the system.

You say in one of your posts that a correct aircon system shouldn't need regassing. This is not true. It is almost impossible to get an aircon system totally gas tight, including with rotating seals like on the compressors, so some loss over years is expected and very occasional top ups are also to be expected.

Also, running with low refrigerant itself isn't an issue, as it will simply mean that the efficiency of the aircon is reduced, or if the system pressure is too low, the pressure switch will not allow the system to engage in the first place.


HOWEVER, BE CAREFUL. The reason for the low system pressure should be investigated. I already said in an earlier post that if it's the evaporator, then you might find PAG oil on the footwell carpet or in the aircon heater box drain. Likewise, Jobsworth in post#2 Said most common issue is the condenser. And most commonly on the condenser at the bottom where it gets more environmental abuse. In both of these instances, it is likely you will be low on PAG oil, which is the lubricant that runs inside the aircon system.

Running an aircon system with low PAG oil is a very bad idea and could toast your compressor ASAP.

Get this looked at for a professional opinion.

Good luck buddy

 

[Petrol Pete]

OP .It has been 4 months , where are we now with your A/C ? . Listen to Jobsworth #2. DO NOT start ripping the car apart to change the evaporator . Unless you charge the system and (their and then) use the sniffer to detect the leak in the cabin (you will probably be able to smell it with MK1 human nose or even see it happening) , OP you do not give us enough detail about your A/C .

1. Did it work just fine and slowly over time become less efficient ?
2. have you had it professionally re charged and serviced.?
3. have you replaced the cabin/pollen filter ?
4. how old is the car and how many miles on it ?

Using A/C with 'low level' is not seen as a problem on many systems because the low level (more concerned with lack of lubricant in the system) is detected and the pump is shut down to prevent damage and it stops blowing cold.

On many MB's (not sure about yours) the A/C pump is being belt driven all the time that the engine is running and its effect is regulated by a valve system on a swash plate so even under no load the pump benefits from PAG oil being in the circuit. They are expensive to replace that is why it is recommended that cars with this type of pump have their A/C (climate) switched on most (if not all) of the time.

ac swash pump - Search Videos

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