Hyundai Repair: Tapping Noise.., sonata 3, trouble code

Question
Hi,

I have the 2006 Sonata LX V6, and recently I can hear the little knocking noise or tapping while driving home with my radio off. The car is fine though, except sometimes I can feel the vibration and power loss when I tried to accelerate. (Sometime i can feel it, sometimes it seems like it's not there anymore.)

I brought it to the dealer and told them that but they said it was normal engine noise. I love this car, but the knocking noise and vibration are really bugging me.

Please, help.

Thanks.

Answer
Not being able to hear the noise, it's difficult for me to say whether it's normal.  My first suggestion would be to return to the dealer and ask to test drive a new or used 2006 or 2007 Sonata 3.3.  If both cars exhibit the same noise, it's probably normal.

In regard to the vibration and lack of power, the dealer will likely need to replicate the issue to even offer an opinion as to whether it's normal, whether it's an actual problem, and what the cause may be.  Since you have a power loss as well, it's possible there may be some sort of diagnostic trouble code stored in the engine or transmission computer.  If found, these can be of significant help to the dealer technician in speculating the possible causes of your problem.

If it occurs enough that a reasonable test drive should expose the issue, ask them to check for the vibration and power loss.  If it maybe happens once a week once every few days, you should expect they'll need to drive the car long enough to get the problem to occur.  On avenue of attack for problems like this is to have one of the dealer technicians drive the car home and back overnight in an attempt to replicate the problem.  Another avenue of attack is to go by the dealer while the problem is occurring and have a technician ride with you at that time.  

But you'll need to understand that dealer technicians are busy and that you may need to wait a little bit for someone to ride with you.  It may also be impossible for any actual diagnosis to occur at the time when you come in for someone to ride with you to feel the problem.