Background: Engineering's introduction into K-12 classrooms has been purported to support meaningful and inclusive learning environments. However, teachers must contend with dominant discourses embedded in US schooling that justify inequitable distributions of resources. Purpose: Drawing on Gee's notion of discourses, we examine how teachers incorporate language legitimizing socially and culturally constructed values and beliefs. In particular, we focus on the discourse of ability hierarchy--reflecting dominant values of sorting and ranking students based on perceived academic abilities--and the discourse of individual blame--reflecting dominant framings of educational problems as solely the responsibility of individual students or families. We aim to understand how these discourses surface in teachers' reasoning about teaching engineering. Method: We interviewed 15 teachers enrolled in an online graduate program in engineering education. Utilizing critical discourse analysis, we analyzed how teachers drew on discourses of blame and ability hierarchy when reasoning about problems of practice in engineering. Results: Teachers drew on engineering education concepts to reinforce dominant discourses (echoing specific language and preserving given roles) as well as to disrupt (utilizing different language or roles that [implicitly] challenge) dominant discourses. Importantly, teachers could also retool discourses of ability hierarchy (arguing for a more equitable distribution of resources but problematically preserving the values of ranking and sorting students). Conclusions: K-12 schooling's sociohistorical context can shape how teachers make sense of engineering in ways that implicate race, gender, disability, and language, suggesting a need to grapple with how discourses from schooling--and engineering culture--maintain marginalizing environments for students.