Q: I20 making rattling noise could it be the faulty steering rack or the brake callipers

Hello. It is impossible to identify a rattling noise without pinpointing the location in which it is coming from. The brakes typically do not make a rattling noise. Usually the brakes make a grinding noise of some kind. The steering rack may rattle if something has broken off inside, but there are many other causes of a rattle that are more common. When does the noise occur? Do you hear it when you are coming to a stop, when you are accelerating, at an idle, at all times? Both the timing chain and the exhaust system are most known for creating a rattle. You also may be hearing what is more commonly known as "engine knock". Unfortunately, sounds can be confusing when describing them, and the very best thing you can do is attempt to locate where the sound is coming from. And from there, diagnosis will be much easier.