Air Con...not very cold!

[molar]

The Air con in my ML320 does not seem to be very efficient/cold compared to other cars (friends/family). It is almost as if there is no air con in the car!

Is it because it is faulty??

Or does the coolant need topped up/replaced...(if there is such thing)

Any ideas?
Thanks

 

[concordepilot19]

Couple of quick checks, I'm not sure if the EC switch on my C Class is replicated on the ML, but when that is pressed, the light comes on and the compressor is disabled (no aircon). Conversely, when the light is off, the compressor is enabled, provided that the outside air temp is > 5 C.

Lift the bonnet with the engine idling and have someone press the EC switch (or do whatever is necessary to bring on the a/c) , you will hear a solenoid click, with a momentary drop in revs, and maybe a hissing as the refrigerant is compressed and evaporated. If not, there may be a lack of refrigerant or other system fault.

I have a digital thermometer (£10 from RS ages ago, prob find one on Ebay), it's very uselful for barbecues and for sticking in the airvent to see if the aircon is working. I find the air temperature ranges from 6 C to 18 C, depending on the cabin temperature selected, and whether the sun is shining. The air temp is more like 24 C with the compressor off.

In comparison, my VW Sharan used to freeze the sphericals off, and use up about 4 mpg, whereas the Merc is more subtle and the fuel consumption doesn't seem to be affected.

Hope this helps.

 

[Andy]

Hi

If the ML is a few years old I would get the AC recharged. It may of lost some of its refrigerant.


Regards

Andy@ www.mercedesservicing.com