Any air-con experts? W215 CL500..

[Max M4X WW]

Hi all,

I am new here and this is the first problem I have had with the car, as it started before I bought it! I will try and keep this brief, but any help welcome!

When I viewed the car before purchasing I realised the air con would not turn on. We found a fault code stored for a flap actuator which was cleared and the system was then re-gassed as it still didn't seem cold.

The air-con seemed to be working (thought it was sub 10oC outside so difficult to tell!) and I bought the car. Everything seemed fine but a week later it wouldn't turn on again. A new fault code was showing for the evap core sensor which I replaced with a FEBI item.

This fault code now displays every few days and goes when I clear it. The air con isn't working as now with the warmer weather it doesn't seem cold. I ran the extra diagnostic with all the values and the refrigerant pressure on the diagnostic display is 4.2 bar with the engine both at idle and not running. This seems low?

Just wondering where to start really! How can I check the compressor is running? Normally they click in and out but I'm told the air-con is never 100% off on these cars (if working!)

Thanks, Max

 

[Borys]

Try reseting ac
Type in you tube w220 air con reset
Worked on mine
On w215/220 specially after regas it has to be done

 

[Max M4X WW]

I have done that a few times! As I said, code keeps coming back.

 

[Borys]

There is a special key combination on control panel to reset Reseting codes via Star won't do a thing I'm trying to help. You should now by now mercs sometimes don't need a fancy diagnostic, lots of hidden menus we don't know about..... Anyways good luck seems you know better

 

[Max M4X WW]

There is a special key combination on control panel to reset Reseting codes via Star won't do a thing I'm trying to help. You should now by now mercs sometimes don't need a fancy diagnostic, lots of hidden menus we don't know about..... Anyways good luck seems you know better

Hi, I did clear the codes via the CC panel. Not Star or the OBD.

I appreciate the reply, didn't mean to sound rude - just crossed wires.

 

[Borys]

Ok no probs

 

[whirsk]

Hi max

I presume your system is r134a refrigerant, 4.5 bar pressure would be approx ambient temp of 18c (engine running) with the compressor running with correct gas charge the pressure would be approx 1bar suction (low side) the high side (discharge) will vary depending on condenser fan motor cutting in.approx 12 -14 bar.
Hope this helps.

Sent from my SM-G920F using Tapatalk

 

[Dec]

Hi all,

I am new here and this is the first problem I have had with the car, as it started before I bought it! I will try and keep this brief, but any help welcome!

When I viewed the car before purchasing I realised the air con would not turn on. We found a fault code stored for a flap actuator which was cleared and the system was then re-gassed as it still didn't seem cold.

The air-con seemed to be working (thought it was sub 10oC outside so difficult to tell!) and I bought the car. Everything seemed fine but a week later it wouldn't turn on again. A new fault code was showing for the evap core sensor which I replaced with a FEBI item.

This fault code now displays every few days and goes when I clear it. The air con isn't working as now with the warmer weather it doesn't seem cold. I ran the extra diagnostic with all the values and the refrigerant pressure on the diagnostic display is 4.2 bar with the engine both at idle and not running. This seems low?

Just wondering where to start really! How can I check the compressor is running? Normally they click in and out but I'm told the air-con is never 100% off on these cars (if working!)

Thanks, Max

In both above picture, the engine is running.
When the air con is switched off, by the a/c button on the heater panel, the compressor is not running, (stationary) air con is off.
When the air con is switched on, by the a/c button on the heater panel, the compressor is running, (rotating) air con is on.

Dec

 

[Uky]

I used to test my 215 AC in wintertime by first setting passenger compartment temperature to "a bit high". Then after a few minutes, selecting recirculation, chosing a significant lower cabin temperature and then turn on the AC. There are two aluminium tubes running on the left side of the engine compartment. One that is thick, and the other that is thin. If the AC compressor is running, the thin tube should get hot (which can be difficult to acheive during the cold season) and the thick tube should be rather cold.

When the AC system is diagnosed for pressure leaks, the system is first emptied of all refrigerant. The volume extracted from the system is measured. Then ,the system is refilled, and an ultra violet light reacting substance is added together with compressor oil.

The system is checked and the pressure is measured. Then the vehicle will be kept overnight at the service center. Next morning, the pressure is checked. IF OK (no change), the vehicle is handed over to the customer. If not, an ultra violet lamp is used for leak detection.

What the layman can do is to check for greasy spots on the radiator and tube connections. Since the refrigerant circulates with compressor oil, the oil stays where the leak is, so in some cases the leak can be clearly seen.

One word of caution: NEVER simply add refrigerant without verifying that there is enough compressor oil in the system. The compressor WILL be destroyed and metal parts could propagate in hoses and tubes.

Sorry for not being able to help with the error codes.

 

[Max M4X WW]

Hi,

Thanks for the reply, a local independent has diagnosed the car as needing a new compressor. There is leaking around the front of the unit and there is some sort of broken metal on the front of the pulley.

I just need to work out which compressor to get, I think there are a few types?