I have few questions

1.) When I started my car getting some sounds from timing Belt then i will do some
spray on it after sometime will start again and dont hear any noise. can you please tell
me why am getting that sounds initially Note:- timing belt is new                                                    
2.) If i run a car in ups ad downs say for example slope areas and speed bump getting
some sounds from back tyre suspension, when i check there is some rusted area on
my suspension. can you please help me to remove such sounds. Note:- when i check
with mechanics they are saying thats not a big deal