Can you sugguest a book that can help me improve my problem solving skills as an engineer?

Unfortunately problem solving needs experience not just reading a book.

1. experience , practice , self improvement 
2. PMP book , Rita Mulcahy book , project human resource knowledge area ,chapter 9
3. Engineering Problem-Solving 101: Time-Tested and Timeless Techniques,by Robert Messler 

No way. Regarding by experience every problems have can make possible to solve. 

There is no specified book.It is a combination of Education, knowledge, experience and Talent.

Problem solving is one thing. There are no specific problems only engineers can handle. If you want to be the best, think of problems as crimes and as crime goes, think like Sherlock Holmes. You can start with "Mastermind: How to Think Like Sherlock Homes". Problem solving using system Watson or system Holmes? Pick your side. But then again, there aren't just two sides.

Usually as a student and knowledge seeker it is best to look at Daniel Pink's book: 

• Drive: The Surprising Truth About What Motivates UsAlthough this book speeks of motivation and drive it teaches us how to effectively work and channel our abilities towards improvement rather than the traditional spoon-feeding text books 
• Design and Technology Textbook IBO publishing ; the book also is amazing as it gives you a situational view of different solution oriented skills, as well as highlights methods and techniques that can be followed step by step to empower our problem solving abilities. 

yes

Engineers of  the soul by Frank westerman 

Problem solving is not a heart study or memorize subject, its a matter of commutative and cumulative experiences with high understanding and sense of skills. 

Problem solving skills can be gained through experience and not just by reading a book.