Hi! I have a ford focus 2016 1.5TDCI manual transmission model. Right from when I bought the car I noticed a weird sound that it does when I shut off the engine It does that sound every time, from the sounds of it, it comes from the EGR valve, or somewhere near it. From inside it always sounds like the car pushes air. Maybe someone has that sound and will tell me what is could be. The engine runs fine and this sound was always there and it does it every time, I'm just curious, because I couldn't find any info on that. Here's a video of that sound (you can hear that sound at about 0:14):

https://www.youtube.com/watch?v=S4BpA-3D_ko

Also while looking at the engine I looked at this component, however I couldn't figure out what it is. Could someone tell me? The guys at the local shop didn't know either, and I can't quite figure out how to google this thing, sice I can't come up with a good description of it. I attached the image and circled it in red

 

The sound is the EGR self-test, totally normal on many modern diesels.

Not 100% sure what that metal can is, possibly some sort of accumulator to smooth pulses/surges from the fuel pump going through the to the rail.

My 2.0 TDCi makes a noise when turned off which is actually the boost solenoid releasing pressure.