Anyone else have a rattling noise coming from underneath the car when the gas engine turns on?

Whenever my gas engine turns on I hear a rattling noise, sounds like a loose heat shield on the exhaust.

Its loudest when the car is cold. You can hear it while idling and at highway speeds.

The car is at the dealership now...

 

Yes. Sometimes, and worse when cold.
Let me know if you figure out what it is, please.

 

The dealer had to replace the downpipe and manifold gasket. They said one of the welds were cracked on the pipe. Not sure if he meant the the heat shield or the exhaust pipe was cracked. The sound is completely gone.

 

cool! glad they found the problem and fixed it!

 

Which dealership did you bring it to?

 

Glad you got it fixed. Sometimes it's like pulling teeth with a dealer to have a problem fixed. I've gotten 'unable to reproduce' more times than I care to admit.

 

I brought the car to Seramonte Nissan. I dropped it off at 12pm and was able to pick it up the next day at 9am. I was pretty surprised on how quick it was done. Hopefully all my service visits will be like this one!!