Abstract This paper investigates the mechanical consequences of abrupt stops of coiled-tubing (CT) injector-head movement during heavy-pipe running-in-hole (RIH) operations. The objective is to quantify the transient dynamic loads produced during abrupt deceleration events, correlate those events with field-observed longitudinal plow marks (LPM), and propose practical mitigation measures to reduce CT string damage and injector wear. Operational data from multiple CT jobs were reviewed, focusing on events where injector speed exceeded 20 ft/min and hydraulic pressure dropped rapidly, causing a drive stall and an abrupt stop. Job files from CT strings removed from service were examined to correlate LPM severity with abrupt-stop events. For each event, injector speed, measured surface weight, and assumed stop time were used to estimate inertial load and total transient load at the injector. Results show that abrupt stops under heavy-pipe conditions can increase transient load at the injector sufficiently to exceed available gripper traction, producing short-duration micro-slippage between the CT and the gripper blocks. This micro-slippage manifests as longitudinal plow marks and accelerates CT wall loss, increasing the probability of subsequent fatigue damage, cracks, and pinholes that can lead to service-quality events and premature string retirement. The paper documents and quantifies a failure mechanism in CT operations in which abrupt injector stops induce micro-slippage-driven longitudinal surface damage. The findings support operational and control-system recommendations—particularly controlled, gradual deceleration and real-time monitoring—to reduce transient loading, preserve CT integrity, and improve injector reliability.