I agree with Davy, if the noise has come on suddenly sounds like a dirt problem. I had a Rio which did the same and because I think the previous owner had not changed the oil religiously. I drained the oil, used flushing oil and refilled with top quality oil and a new Kia oil fliter and the poblem disapeared. For what its worth, may be a plan.
I did have this problem on my old Kia Mentor 1.6ltr 8valve and I tried the flushing oil but in the end I had to take the HLAs out and cleaned then with carb cleaner. I had about 2 that were noisy.After that I had no problems.