Intern/Co-op - Refining Mechanical Engineer (Fall 2026)

About the role#

As a Mechanical Engineering intern or co-op at a Marathon refinery, you will gain exposure to industry codes, best practices, and the collaborative nature of refinery engineering. You will work alongside professionals managing specific portions of the refining process, often rotating through multiple areas to build a comprehensive understanding of plant operations. This role focuses on developing critical thinking, project management, and professional communication skills.

What you'll do#

Interns typically serve in one of two capacities:

• Area Refining or Project Engineering: Develop project management skills by creating scopes, estimates, and schedules. You will oversee the design effort and assist in the construction process for various projects.
• Reliability Engineering: Support the Maintenance Department by designing and developing equipment improvements. This includes conducting root cause failure analysis, optimizing maintenance programs for rotating equipment like pumps and compressors, and troubleshooting fixed equipment such as pressure vessels, heat exchangers, and piping systems. You will also explore new technologies in design, materials, and repair methods to improve equipment run times and reduce costs.

What you'll need#

• Current enrollment in a Mechanical Engineering degree program.
• Strong academic performance.
• A valid driver's license.
• Authorization to work in the U.S. on a full-time, indefinite basis without the need for visa sponsorship.

Location & details#

• Term: Fall 2026.
• Modality: On-site.
• Employment type: Full-time, paid.
• Locations: Findlay and Canton, Ohio; El Paso and Texas City, Texas; Anacortes, Washington; Wilmington and Martinez, California; Mandan, North Dakota; Salt Lake City, Utah; Robinson, Illinois; Detroit, Michigan; Catlettsburg, Kentucky; St Paul Park, Minnesota; Garyville, Louisiana; and Kenai, Alaska.