is the crankshaft sensor inside the motor or ouside

It's on driver's side back of the engine... Better yet... General: http://www.pelicanparts.com/techarticles/MBZ_Tech_Index-W210.htm Specific to CSP W210 (e320) http://www.pelicanparts.com/techarticles/Mercedes-W203/ENGINE-Crankshaft_Positioning_Sensor_Replacement/ENGINE-Crankshaft_Positioning_Sensor_Replacement.htm I hope this helps... I've been going through what I assume you're chasing down. Just replaced CPS 5 minute job with right tools 8mm female-Torx swivel socket, Amazon (Prime overnight all under $40.00) for CPS. Best wishes, flpneo