Black Smoke & Starting Issues: Insignia Diesel Problems

Hey there! I've got some experience with diesels, and this sounds really similar to what I faced with my 2013 Vauxhall Astra diesel last winter. Had almost identical symptoms, black smoke, cutting out, and that annoying cold start issue. Turned out my fuel filter heater wiring harness was damaged, probably from road debris or just wear and tear. Got it fixed at my local garage for around 110 Euro. The mechanic showed me where the connector had corroded and partially melted. Before jumping to conclusions though, what's your mileage? And have you noticed any other warning lights besides the check engine light? Also, when was the last time you changed your fuel filter? These details would help nail down if it's the same issue. If it is the same problem, it's not a massive job, but definitely needs sorting before it gets worse. Mine took about an hour to fix.

Thanks for your insight! My Insignia's at 30631 KM and had its last service about two months ago. Not seeing any other warning lights besides the check engine one. Actually, come to think of it, these issues started showing up right after that last service, maybe there's a connection there? The symptoms you described with your Astra sound spot on to what I'm experiencing. Might be worth checking that wiring harness. Thanks for the heads up about the repair cost too, at least I know what I might be in for!

Hey again! Yeah, those symptoms starting right after the service definitely rings some bells. You know what's funny, the exact same thing happened with my Astra! Looking back, I reckon the mechanics might've accidentally damaged or not properly reconnected the wiring harness during the service. When I had my issues, the timing was super similar. I initially thought it was just coincidence, but when my mechanic dug deeper, he found that the connector had been slightly misaligned during reassembly after the service. That's what caused mine to start acting up. Since you're at 30631 KM (mine was around 35000 when it happened), the wiring should still be in decent shape if it wasn't disturbed. I'd definitely suggest getting it checked out, specifically mentioning the service timing to your mechanic. In my case, once they fixed the connection properly, all those symptoms disappeared literally overnight. Quick tip from my experience, get them to check all the connections around that area while they're at it. Sometimes when one thing's been disturbed, there might be other loose connections nearby. Better to catch everything while they're in there! Let me know how it goes, I'm curious if it turns out to be the same issue as mine!

Thanks so much for all the detailed advice! You've actually made me feel a lot better about this whole situation. I've just booked it in with my local garage for tomorrow morning and specifically mentioned the wiring harness and the service timing like you suggested. I'll definitely have them check all the surrounding connections too, that's a really good point about catching everything while they're in there. It's quite relieving to hear that your issue was sorted so quickly once they found the problem. Really hoping mine turns out to be something similar, those overnight fixes are the best kind! I'll update the thread once I get it sorted, just in case anyone else runs into the same problem with their Vauxhall. Thanks again for all your help, it's great to have someone who's been through the same thing!