I dont know if I overcharged or undercharged my AC but my engine is making whining noises when at low RPM and yesterday the FAN/Compressor is turning on and quickly off.. i called a mechanic today.. and he said he'll have to listen to it to know exactly what the problem is.. hopefully all it is .. is for him to drain freon and refill to the correct amount crossing fingers..

 

Probably overcharged causing compressor noise.
They should evacuate and charge by weight/pressures and hopefully no damage was done to the compressor.

 

Thanks! Yeah i just did it this weekend, never again am I buyin them cans from AUTOZONE.. hopefully that is it.. havent been using the AC.. since.