Ditto. My '92 300E uses two dual diaphragm vacuum valves to command either 80% or 100% recirc air. Right now, one or both of my valves has a leak on the 100% side. Therefore, I only get 80% recirc air no matter what until I replace the guilty valve/valves. Until then, anytime the temp is above about 88 degrees, it takes a LONG time for my car to cool down. You need to see how your recirc system is set up for your car.