Hello, since i purchased my car. I get a noise from the engine after its warmed up. When i go to start it. Its not mechanical, i believe its coming from some emissions related area under the hood. Its like something "running" then it turns off once i start to drive

 

Evaporation purge solinoid, or fuel pump maybe?

 

Otherwise known as air pump (for cats)

 

sounds like air pump

 

i also say air pump....normal tho

 

Lol I've never owned a car with an air pump