The internationalization of educational settings has been increasingly leading to wider recognition of English Medium Instruction (EMI) in higher education institutions, and a growing number of studies have investigated EMI policies of universities with diverse research foci. However, only little attention has been paid to classroom interactional dynamics with a particular focus on actual teaching/learning practices, and an examination of translanguaging as a pedagogical resource in multilingual learning environments has not been an exception. Although previous studies have explored lecturers' translanguaging practices in EMI classrooms, students' translingual contributions seems terra incognita. In this regard, using multimodal Conversation Analysis, this study closely examines translingual peer involvement through students’ multilingual and multimodal repertoires that become observable while resolving troubles in understanding. Based on the video-recorded classroom interactions in an undergraduate program on Mathematics and Science Education at a state EMI university in Türkiye, the current study demonstrates how students actively participate in ongoing interactions to resolve understanding troubles. The findings show how translingual peer involvement emerges across English and Turkish languages, and an invented language, and creates space for the lecturer to enhance learner contributions. The study brings new insights into EMI classroom discourse in an emerging context.