I have a 96 ES300, bought two years ago from dealer. Yesterday when I turned on the air conditioner for cooling, felt only cool air coming out but not cold at all. No lights were blinking, so possibly due to low Freon level. During recharging, cold air started to flow after about 1-2 pounds of R134a infusion. In total, I recharged about 4 pounds until low service port psi reached 45-50. Then I noticed some kind of intermittent sounds (compressor engagement?) that happened every 5-10 seconds lasting 1-2 seconds. Every time the sound started, engine idle rpm would drop ~100 rpm, then back to normal rpm when it stopped. I don't remember anything like this before, or maybe I am just too picky today that this is all normal due to the compressor drawing engine power. Anyone has similar experience? The ambient temp was 83 F. Thanks!