The Mercedes-Benz E500 is part of the E-Class line of executive-size luxury cars manufactured by Mercedes-Benz. The Mercedes E500 can suffer from AC (air conditioning) problems, which can often be resolved via some basic troubleshooting checks.
If a humming noise emanates from the radiator fan of your Mercedes E500 AC system, a bad idle air valve -- which either allows or blocks the passage of air through the throttle body -- may be to blame. Check the valve for signs of wear or sticking and replace it as needed. Also check the condenser fan and fan motor for signs of damage and make any necessary replacements.
Low freon levels in the compressor of a Mercedes-Benz E500 AC system can cause it to fail to cool while the engine idles. Take the Mercedess E500 to a certified mechanic for a freon level and pressure check.
If the Mercedes Benz E500 fails to produce cold air, the serpentine belt, which enables the compressor to rotate, may have slipped or failed. Check the belt for slippage and adjust it as needed. If it's worn or otherwise damaged, replace the belt.
