Peugeot 107 preheating lamp issue

Whoa, sounds familiar! I had almost the same symptoms on my 107. By any chance, have you checked the glow plugs? When the glow control unit goes bad, it can cause engine misfire and a cloud of smoke. Did you run a diagnostic test?

Glow plugs I haven't checked. Diagnostic test points towards a defective glow control unit. Are you suggesting your issue was also the control unit? And do you know what "engine misfire" means?

Yep, the control unit was the culprit! And 'engine misfire' basically means one or more of your engine's cylinders aren't firing properly. I'd suggest a workshop visit; they'll pinpoint it. In my case, the cable or plug connection of the component was defective.

Thanks for the confirmation! It's booked in. Turns out the cable or plug connection was indeed defective. Repair cost me 95€. Appreciated!