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Mechanical System Engineer Jobs in California (NOW HIRING)

Evaluate vendor quotations and review supplier engineering documentation. * Ensure compatibility and integration of mechanical, process, electrical, and control systems. Project Execution * Support ...

The System Engineer focuses on troubleshooting, maintaining, and stabilizing complex electro-mechanical and automated systems to ensure safe, consistent system uptime. This role is not commissioning ...

The System Engineer focuses on troubleshooting,maintaining, and stabilizing complex electro-mechanical and automated systems to ensure safe, consistent system uptime. This role is not commissioning ...

The System Engineer focuses on troubleshooting, maintaining, and stabilizing complex electro-mechanical and automated systems to ensure safe, consistent system uptime. This role is not commissioning ...

System Engineer

Lathrop, CA · On-site

$71 - $107/hr

The System Engineer focuses on troubleshooting,maintaining, and stabilizing complex electro-mechanical and automated systems to ensure safe, consistent system uptime. This role is not commissioning ...

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Showing results 1-20

Mechanical System Engineer information

See California salary details

$62.7K

$108.9K

$150K

How much do mechanical system engineer jobs pay per year?

As of Aug 24, 2026, the average yearly pay for mechanical system engineer in California is $108,861.00, according to ZipRecruiter salary data. Most workers in this role earn between $80,400.00 and $129,800.00 per year, depending on experience, location, and employer.

What does a mechanical system engineer do?

A Mechanical System Engineer designs, develops, and oversees the installation and maintenance of complex mechanical systems in various industries. Their work often involves integrating mechanical components with electrical and software systems to ensure the overall functionality and efficiency of machines or equipment. They may be responsible for tasks such as performing simulations, analyzing system performance, troubleshooting issues, and collaborating with multidisciplinary teams. Mechanical System Engineers play a critical role in industries like automotive, aerospace, manufacturing, and energy. Their expertise ensures that mechanical systems operate safely, reliably, and efficiently.

What are the key skills and qualifications needed to thrive as a mechanical system engineer, and why are they important?

To thrive as a Mechanical System Engineer, you need a solid background in mechanical engineering principles, system design, and problem-solving, typically supported by a bachelor's degree in mechanical engineering or a related field. Familiarity with CAD software (such as SolidWorks or AutoCAD), simulation tools, and industry certifications like PE (Professional Engineer) are often required. Strong analytical thinking, teamwork, and effective communication skills help distinguish top performers in this role. These skills ensure efficient design, implementation, and maintenance of complex mechanical systems, leading to reliable project outcomes and innovation.

What are some common challenges mechanical system engineers face when working on multidisciplinary projects?

Mechanical System Engineers often collaborate closely with electrical, software, and civil engineers on multidisciplinary projects. A common challenge is ensuring effective communication between teams, as each discipline may use different technical language and have varying priorities. Managing integration issues and aligning timelines across departments can also be demanding. To overcome these challenges, Mechanical System Engineers typically participate in regular cross-functional meetings and use collaborative project management tools to ensure alignment and successful project delivery.

What is the difference between Mechanical System Engineer vs Mechanical Design Engineer?

AspectMechanical System EngineerMechanical Design Engineer
Primary FocusDeveloping and integrating mechanical systems within larger projectsCreating detailed mechanical component and product designs
Work EnvironmentSystems integration, testing, and validation in manufacturing or engineering firmsDesign studios, CAD modeling, and prototype development
Required CredentialsBachelor's in Mechanical Engineering, relevant certificationsBachelor's in Mechanical Engineering, CAD certifications

Mechanical System Engineers focus on integrating and managing entire mechanical systems, while Mechanical Design Engineers concentrate on designing specific components. Both roles often collaborate but serve different stages of product development and system integration.

What cities in California are hiring for Mechanical System Engineer jobs?

Cities in California with the most Mechanical System Engineer job openings:

Infographic showing various Mechanical System Engineer job openings in California as of August 2026, with employment types broken down into 1% As Needed, 78% Full Time, 16% Part Time, and 5% Contract. Highlights an 91% Physical, 2% Hybrid, and 7% Remote job distribution, with an average salary of $108,861 per year, or $52.3 per hour.

Mechanical System Design Engineer

Irvine, CA

Full-time

Posted 12 days ago


Job description

Nikkiso Clean Energy & Industrial Gases is a leading provider of cryogenic pumps, heat exchangers, process systems, services, and solutions for the LNG and industrial gases industry. We are a subsidiary of Nikkiso Company Ltd, a leading industrial manufacturer headquartered in Tokyo, Japan, with over $1.5 B in annual revenue, 8000 + employees worldwide, and publicly traded on the Tokyo Stock Exchange.


The Turbomachinery Auxiliary Systems Engineer is responsible for the design, specification, integration, and commissioning support of auxiliary systems for turboexpanders, compressors, turbines, and other rotating equipment used in energy, industrial gas, cryogenic, geothermal, and process industries. The engineer develops complete system solutions including lubrication systems, seal gas systems, cooling systems, instrumentation, controls, piping, and skid-mounted process equipment while ensuring compliance with applicable industry standards and customer specifications. 


System Design & Engineering

  • Design and develop auxiliary systems for turboexpanders, compressors, turbines, pumps, and rotating equipment.
  • Prepare process flow diagrams (PFDs), piping and instrumentation diagrams (P&IDs), equipment layouts, and system architecture drawings.
  • Specify and size auxiliary equipment including:
  • API lubrication oil systems
  • Seal gas systems
  • Coolers and heat exchangers
  • Pumps and filtration systems
  • Pressure vessels and accumulators
  • Control valves and instrumentation
  • Interconnecting piping systems
  • Perform process calculations for flow, pressure drop, heat transfer, and equipment sizing.

Equipment Specification 

  • Develop technical specifications, datasheets, bills of materials, and procurement packages.
  • Select equipment in accordance with customer requirements and industry standards.
  • Evaluate vendor quotations and review supplier engineering documentation.
  • Ensure compatibility and integration of mechanical, process, electrical, and control systems.

Project Execution 

  • Support projects from proposal through commissioning.
  • Participate in design reviews, HAZOPs, customer meetings, and bid clarification meetings.
  • Coordinate engineering deliverables across multiple disciplines.
  • Manage technical interfaces with customers, EPC contractors, and equipment suppliers.
  • Provide technical support during manufacturing, assembly, factory acceptance testing (FAT), and startup activities.

Controls & Instrumentation 

  • Define instrumentation requirements and control philosophies for turbomachinery packages.
  • Develop control narratives and cause-and-effect documentation.
  • Support PLC/DCS interface requirements.
  • Review control logic for process and machinery protection systems.

Compliance & Standards 

  • Ensure designs comply with applicable standards, including:
  • API 614
  • API 617
  • API 661
  • API 670
  • ASME Section VIII
  • ASME B31.1 and B31.3
  • ISA standards
  • Customer specifications and project requirements
  • Participate in design verification and quality reviews.

Commissioning & Field Support 

  • Support installation, commissioning, troubleshooting, and performance testing.
  • Investigate field issues and develop engineering solutions.
  • Provide aftermarket support for operating equipment.
  • Support root-cause analyses and reliability improvement initiatives.

  • Bachelor’s degree in Mechanical Engineering, Chemical Engineering, Petroleum Engineering, or related engineering discipline.
  • 3-5 years’ experience working as an instrument and control engineer especially in turbo machinery.
  • Knowledge of the National Electric Code (NEC), UL, International Electrical Standards (IEC) , CE Directives, ATEX, etc., ISA Standards, Hazardous codes, CSA electrical panel safety codes and SIS
  • Application of the above standards to cryogenic pumps and turboexpander control systems.
  • Demonstrate an excellence interpersonal skills including communication, be a self-starter, have a positive make-happen attitude, to be able to handle multiple tasks, and be a team player.
  • Demonstrate the ability to self-improvement.

Work Environment


This job operates in both a professional office environment and a manufacturing/production environment. Commitment to safety is essential. This role routinely uses standard office equipment such as laptop computers, photocopiers, and smartphones.

 

Physical Demands


While performing the duties of this job, the employee is regularly required to talk or hear. Specific vision abilities required by this job include close vision and ability to adjust focus. This would require the ability to lift files, open filing cabinets and bend or stand on a stool as necessary. 

 

Other Duties


Please note this job description is not designed to cover or contain a comprehensive listing of activities, duties or responsibilities that are required of the employee for this job. Duties, responsibilities, and activities may change at any time with or without notice.


Nikkiso CE&IG is proud to be an equal opportunity employer. We celebrate diversity and are committed to creating an inclusive environment for all employees. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, or protected veteran status and will not be discriminated against on the basis of disability.