hey guys im new here so sorry if im in the wrong area.

i have a 2012 G37xS Sedan. only got 8,700 miles on it. over the holiday i was doing some traveling around the state and got to my destination. as soon as i shut the engine off i had move my car and as soon as i started the car it made a lond metal clunk noise that came from the engine area directly under the car. i shut the car off and wait like 10 seonds and turned it back on and it did it again for like 3 days. yesterday i took it to the dealer, they told me was because of the exhaust creating a backward pressure. when i showed them what was going on and told them to listen they were all in the back listening to the exhaust. i feel as if they just threw the issure over there shoulders. idk what to do or where to take it.

the only thing i have done to my car so far is a muffler delete. never had i have a problem like this before on any other car that had exhaust mods.

please help.

 

Could be your timing chain tensioner. My G's been doing this for a while now. The only thing is you cant be 100% I could replace the part and the noise could still be there. My suggestion would be to go to another dealership and have them look at it, you might even walk away with a new engine haha.

 

on a cold start you dont get any noise?