Mirach9320

I am having AC problems...AC cold when car is cold vent blows 40 degree air on max for about 5 min, after 10 min I am getting 100 degree air (ambient) I suspect hot water to heater core not being shut off...First question is Does the W164 have a shut off valve? I am getting conflicting info off of google searches. I found reference to one behind the RH cylinder head. Has anyone had any experience with this valve? Thanks

Maj. Dundee

Get a scanner and check for codes in the A/C.