New timing belt replacement

i have 2005 hyundai sonata with 65 k miles on it just recently replace with a new timing belt but after it was done and left the shop the car engine start running noisy like i just installed a muffler. there’s a vibrating noise during accelaration and decellaration and most of all that bothers me is like it’s affecting my RPM. i called my mechanic and he says its normal to have these conditions after replacing my timing belt and it will just ease away after couple days and if not just bring it back to them to be rechecked. what do u think what happen on the car? is the timing belt over tighten? what might possibly had happen? thanks i need some suggestions on this matter!

Did You Replace The Belt As Routine Scheduled Maintenance Or Did The Belt Break Or Was There Another Problem ? Was The Car Running Perfectly When It Went To The Mechanic ?

If it was running perfectly when it got there then it should run perfectly when it leaves. There is no break-in period. You should detect no difference in operation or sounds from the moment you dropped the car off and the moment you picked up the car.

There is a problem and driving the car in this condition without knowing what the problem is can possibly lead to some serious engine damage. Guesses can be made about timing issues or other errors, but they are only guesses. Have the car diagnosed and fixed immediately.

CSA

My guess is he did not get the timing right and that can cause some big problems. It could be many different things, but it is not normal.

It is not normal. It will not ease away after a couple of days.

I concur with CSA and Joseph. This should be diagnosed and corrected without further ado. However, if it was replaced because the old one broke, we need to know that to help.

Avoid a mechanic that says this is perfectly “normal.” And if that wasn’t bad enough, he tells you just to keep driving it? If he were a doctor, this would be malpractice.

This mechanic’s explanation is completely bogus. The car should run perfectly from the start. Print this thread, show it to them, and tell them we said so!