Research is clear that women and under-represented ethnic and racial minorities experience engineering classroom climates differently than their male and predominantly white peers. However, little research has investigated differences in engagement and knowledge building between dominant and non-dominant groups in engineering contexts. In this study we examine gender and ethnic differences in student engagement and knowledge building in engineering energy science classrooms. Results indicated that there were significant group differences in students' perception of support for question asking, affective engagement, and behavioral-effortful class participation. Follow up comparisons of gender-ethnicity combinations revealed insight into the differences among women and under-represented racial and ethnic minorities. White males consistently self-reported significantly higher levels of question asking, affective engagement, and effortful engagement than students from many UREM groups. White females, multiracial females, and multiracial males consistently self-reported lower levels of question asking, affective engagement, and effortful engagement than students from many other backgrounds. Follow up comparisons of gender-ethnicity combinations revealed insight into the differences among women and under-represented racial and ethnic minorities.