My 01 honda accord was driving perfectly without any problems until I got the oil changed. Two weeks after a O-ring popped out and all the oil came out. I took it to a mechanic and he replaced the o ring and suggested I get a timing belt kit since the belt was covered in oil. Now when I drive it, the engine does not sound the same and is a lot louder. Could this be because of damage to the engine or something to do with the parts not being installed properly??

 

Is the o-ring you are talking about one of the shaft seals inside of the timing belt cover?

If so, then I am guessing that the mechanic replaced the seal and both the timing and balance belt.

My guess is that the timing belt was installed off 1-2 teeth. Take the car back to the mechanic to get the timing belt installed properly.

 

It was one of the shaft seals. They did replace both of them. I will take it back to him and have him make sure it was installed correctly.

Does having the belt off 1-2 teeth cause any damage to the car?

 

It will run poorly. I would not drive unless necessary. I don't think being off a tooth will cause valve damage.