Engineering educators express concern that undergraduate engineering students solve problems procedurally without the necessary conceptual understanding. While research in engineering dynamics has focused on using technology to improve student performance, this article focuses on using representations for modelling problem solving in the lecture. This is an in-depth, qualitative case study of the pedagogy of an experienced lecturer in a dynamics course in a professional undergraduate engineering programme at a South African university. Social semiotic multimodality is used to analyse the lecturer's purposeful, contextual language choices. The analysis shows how the lecturer creates -- using the available space, media and time of the lecture -- multiple opportunities for students to access the valued practice of using a complex dynamics concept meaningfully in a heuristic to problem solve as a student and engineer-in-training. The findings from the case study surface points of engagement on problem solving pedagogy in the lecture space.