Hello,
You will be able to mitigate a lower than average GMAT through all of the other components of your application. You have a strong GPA so that is a good start, and the fact that you focused on mechanical engineering is helpful too.
It is hard to gauge your work experience without knowing your accomplishments and impact you have made there. However, the average years of work experience is closer to 5, so if you choose to apply with fewer years, make sure you demonstrate why now is the time. And because of your lighter experience, it’s even more important to show you have made an impact and demonstrated leadership there. Ideally this will be supported by strong recommendation letters as well. It will also be important to explain why you want your MBA, and to also illustrate the skills you already have which are transferable. Be sure your story makes sense, and is realistic and specific. I would suggest waiting until you have at least 4 years of full time work experience though.
Regarding extracurriculars, make sure to really emphasize your leadership roles you have taken on, especially as a volunteer and a mentor.
Even with a strong application, if you haven’t already, I still suggest taking the GMAT up to 3-4 times. You have nothing to lose since schools will only look at your highest score. And even a slight increase can boost your profile. If you continue to strengthen your profile as I have mentioned, you do have a chance at your target schools, but they are extremely competitive, and each school simply does not have the room to admit all the world's qualified applicants. For that reason, I suggest apply to several schools, including reach, target and safety. Hopefully they will see that you have a compelling story and are someone who will add value to the classroom and community.
Good luck!