Tell me that was not after putting everything back together.

 

Yeah, I took that this morning.... but it's totally normal. I just felt like freaking some people out.

 

What is it normal break in or what?

 

No it's due to the thermal expansion of the forged pistons. They are slightly different sizes between cold and hot. So what you are hearing is the piston skirt slapping the cylinder wall. It's known as piston slap. Once it's warm you can't even hear it.

 

Nice, you have the Howerton Meth kit right?

 

Yeah.

 

I wish I had taken a video of mine with the hood up. This was my '09 R56 about 2 years ago. All stock, no fancy pistons but I figured I would share.

 

I've never heard piston slap that sounded like that, so I hope you're right and it's nothing more serious.

 

Not all of it was slap. Some was normal cold start noises.

 

My car has always done this but for some reason I thought it was a new noise last week and had a minor freak out. Glad I saw this to remind me it is just a normal mini thing!