Your best bet in finding a job in England as a mechanical engineer is to have a look through online job portals. Are you willing to accept a job doing something else? Your first step will have to be finding work, as these days you can only get a working visa through your employer.
Yes, doing your masters degree will definitely open some doors in the future, but if it's not financially viable and you want to move to England as soon as you can, you might want to look at doing something else for a while. Finding a job to support you while you study towards your masters could also be an option.
I would definitely try online job portals first, sometimes you can be pleasantly surprised by what you find.
Emma summed it all regarding how to find work in the UK or another path is to study towards Masteral Degree as I know some people who had taken their Masteral Degree and gained the status as students. In the future, once you ready to move to the UK, I could be of help to find you a convenient and affordable accomodation.