My Speedster 2.2 (NA) has been having this noise since this summer. It occurs when motor is cold, or warm and just being off for only 15 minutes. Sound goes away after few minutes.
Sound was recorded from the trunk. The noise in question is at 25s and onwards.
Is it a leaking exhaust manifold? Cracked maybe?
Edited by Hekke, 18 November 2014 - 03:18 PM.