Mercedes-Benz 2007 ML350 AC problem

[krash]

Hello kind Sirs,

I seek your expertise in the following matter:

I have a 2007 (w164) ML350 which was out of operation for about 5 years.
Not properly stored, just left in our garage, protected by rain but still outside for 5 years.
Due to my father's recent death, i decided to sell our other car and bring the ML back to life.

All was fine, minor repairs at the dealership (only has ~30k miles) but there seems to be an issue with the A/C.

Although (i think) it worked for a short period of time, it stopped working and only brings in just air

Took it back to the dealership, where they filled it up with Freon, but according to them there was enough freon already in it to work properly.
The guy hooked it up to the star obd thingy, and ran some diagnostics but couldnt fix it.
He told me that "there is probably some blockage in the freon pipe (since the compressor seems to be working) and i should just operate it normally for a couple of weeks and see what happens", turn it on and off etc.

- Is the freon blockage a plausible problem?
- Is there any better solution than to wait a couple of weeks? (like flushing the system? does such an option even exist? )
- Any other common advice you could give me?

Thanks in advance,
Regards,
K

[Cusser]

I hope the dealership didn't charge you money for the non-fix. That would be unjust enrichment, the legal term. You were paying for a fix.

[Tim]

If system was blocked/plugged. Your pressure readings would spike. So not sure what the mechanic is looking at if the compressor is working and has normal pressures.

[Dougflas]

Could be blend door problems especially sitting for 5 years.