grinding noise during acceleration and air condition problems

[menz]

I am having a trouble i think it is with the transmission. I hear a grinding noise while accelerating at around 1500 rpms and goes away after that before i reach 2000. it happens at every gear first, second, reverse etc... It does not when I am in normal or park. I have a 2007 toyota yaris 1.3 litre automatic transmission. My car now has 264thousand kilometers. I own this car since 2007 brand new. I think the sound has been here for quite a while. I also hear a whining noise during acceleration I think this is how it all started. Unfortunately, I have been doing the maintenance at a service center I know and can not remember what they have been doing about the transmission oil, if they change it or just added oil. I think the last time was they added some oil around 190thousand kilometers. Last time i went there they told me the oil was fine. so any help would be much appreciated about this matter. the other problem I have is that my air condition all of a sudden is not cooling anymore. I went to charge the cooling gas and the guy told me that I have a leak in the serpentine. I do not know what is it exactly and i hear the leak noise. He said there is nothing he can do about it at the moment and that I have two options either weld the leak or buy a new one. So how much would a new one cost and would welding where it leaks is a good alternative or not. It is really hot here in Egypt and I use my car for travel on the highway only 270 kms daily to and from work. please help my yuri is sick