Originally Posted by mrad01
Here is a recording of my sound: http://m-works.co.nz/M3Rattle4.mp3
You can hear the noise just after the engine fires. It was MUCH louder in real life.
Insist on a solution.
Damn, that sucks, mine sounds just like that. It only seems to do it if it's sitting for more than a day though (which makes leaky check valves seem plausible). I talked to the dealer and they want to do some cold starts. I've been recording them recently but it hasn't happened again because I've been driving it everyday. I only noticed it over the holidays when I wasn't driving the car every day. I've only got 5 months left on my warranty too...
This was posted earlier but, this also sounds like mine: