I noticed a sound coming out of the engine bay after I shut off the MCS last night. The sound is the sound of air escaping from somewhere near the plug closest to the passenger side, or the oil cap area and it lasts for about 5-6 seconds until the air is expelled. Any idea what this is or if anyone's experienced something like this?

I've checked all the fluids, hoses, and topped off on oil. Only other change was installing an NM Engineering Hi Flow Intake.

I drive an 09 R56 S w/ 70k on the clock. Any ideas? Thanks in advance.

 

Post a video

 

Have an aftermarket CAI? Mine always makes a sucking noise a few seconds after shutting the car off.

Edit: just saw you installed a new intake. Willing to bet thats what you're hearing

 

Weasel, that may be what it is. It's strange though because the sound originates not from the intake but over by the valve cover/gas cap/plugs.

I'll get a video up tonight!