c250d cold start misfire & white smoke - seeking solutions

[bubblygummy30]

Hey all! I've got a w205 2015 c250d bluetec with a peculiar issue during cold starts. When starting from completely cold, it runs fine for the first few minutes, but as it reaches around 40-50 degrees, it starts misfiring, blowing white smoke, and emitting a strong diesel smell. Oddly, once the car is fully warmed up, everything clears up, and it drives fine. I've replaced the injector for cylinder number 2, but the problem persists. Any ideas on what could be causing this? Your insights are highly appreciated!

 

[bubblygummy30]

 

[markjay]

Welcome.

Is the EML on? Have you or the garage used STAR? Did you replace the no 2 injector because of a specific fault code? If so, what was it, and are there any fault codes showing currently?

Also, one way to further diagnose the issue would be to record live data while the car drives through the rough patch.