Air conditioner

STARPARTNER

MEMBER
2000 MERCEDES BENZ C230
2.3L
4 CYL
RWD
AUTOMATIC
123,700 MILES

Have brought the level of R134 charge to specs. Everything is fine when ambient temperatures are at or below 95 - 98 degrees Fahrenheit. Engine fan is running. First electric fan engages as engine temperature rises to normal range. Second fan immediately kicks in when AC is engaged. Cabin filter is clean. Good airflow from vents. If ambient temp is 90-95 or less vent output varies between 45 - 58. (AC type stick thermometer) However if outdoor air climbs to 100 degrees plus, the system cycles in at five to seven seconds then out two to four minutes. And vent output climbs to 100 plus. My mechanic (retired MBZ lead mechanic from Walters MBZ in Riverside, California), says these "older" Benzs just are not good above 100 degrees. This makes no sense. I bought from Walters in 2002 with 11,000 miles and this is the first time I have had this problem. I currently am living in Indio where temperatures are 105 to 112 plus everyday. On fixed income and can not "just replace". Your help will be greatly appreciated. Thanks. TAJ

1 Reply

CARADIODOC

MECHANIC
33,871 POSTS

How did you check the amount of refrigerant in the system? From your description, it sounds like the high-side pressure is going too high, and the compressor is being turned off to prevent blowing the pressure-relief plug. This can be aggravated if there is too much refrigerant in the system.

Also look at the condenser for blockage from leaves and a butterfly collection. If it can't get rid of the heat from normal air flow, the high-side pressure will go too high. You can see that if you have a gauge set connected.