I am a 4th year PhD student in Mechanical Engineering at a Tier 1 University. I have joined the current research group due to funding reasons but never really liked the project. The project is not academic in nature (Not possible to get any decent publications, no design or innovation aspects), more like the sponsoring company had an engineering problem that needed a solution.
My advisor is a good person but he is not an expert in this field and not sure why he accepted the project. I have struggling for some time and my hate towards the project has recently increased and I feel that I cannot carry on with research anymore. I tried speaking to my advisor but he did not like the fact that I was belittling the project, and said I was ungrateful towards him even though he funded me.
That coupled with scare of poor job prospects in mechE have been haunting me. I am also sacred that if I tough it out and finish I might end up being overqualified for industry.
Did anyone else face a similar problem? Would like to know how acceptable is it to leave a PhD program in the 4th year and apply to a different program?
EDIT: Thanks for the answers everyone. I probably should have given more background information. I was unable to secure any funding in my first year (spent time doing courses on my own dime) and towards the beginning of my second year I was ready to accept whatever project came my way and chose this project when there was an availability.
The project was a collaboration between a simulation group (Prof. B) and a mechanical testing group (My advisor's, say Prof. A) and was already halfway through when I joined. Prof. B was the lead PI and had dictated the terms and I spent the next few years just doing the required testing for simulations. Regarding the project (can't name it due to privacy concerns), it has very little academic value, we were able to get out only one article in a low impact journal in the entire duration of the project of which I am the second author. People in my lab usually publish 4 journals for graduation. The project was also very hectic with meeting the sponsors twice a week. It felt more like working in a company and the skills I acquired are more of a master's level.
That is the reason I called it overqualified (a PhD with Masters level skills). I had tried a few times to change the project but was met with resistance from my advisor and I did not oppose strongly for fear of being fired. Now I am really scared of job prospects. I understand that I am responding very late. I did speak to a few people in the department and most are suggesting it is stupid to start another PhD at this stage. Another option I was suggested is quitting with a Master's and finding a job. Frankly, I am not sure what to do.