Rough-Running Insignia: DPF Pressure Problems & Fixes

Hi there! I've had some experience with diesels, and your symptoms sound very familiar. I dealt with almost the same issue on my 2015 Vauxhall Astra diesel last year. Had similar symptoms, rough running, black smoke, and DPF troubles. Turned out the exhaust back pressure sensor was faulty, causing all these problems. Got it fixed at my local Vauxhall specialist for about €250, worked like a charm after that. Could I ask what engine size your Insignia has and how many miles are on it? This would help me share more relevant details from my experience. Also, have you had any previous DPF issues? Best regards, Mike (moderate car experience, mostly with Vauxhalls)

Latest service was done at 158k, about 4 months ago. I'm experiencing exactly what you described with your Astra. The sensor issue sounds like it could be the problem, my symptoms match up perfectly. Did you notice any warning lights before the black smoke started? Mine just suddenly popped up during motorway driving. Been avoiding longer trips since then, just using it for essential short runs. Cheers for the tip about the exhaust back pressure sensor. I'll definitely get that checked out first, the price you mentioned sounds much better than what I was fearing it might cost!

Hey! Yeah, with my Astra (2.0 diesel), the warning light actually came on gradually. First, it would flicker occasionally during motorway drives, especially when accelerating hard, before becoming constant. It's interesting that yours came on suddenly, though that's not unusual with these sensors, they can sometimes fail quite abruptly. Just to add to my previous response, when mine started acting up, I did try a few short runs thinking it might help, but honestly, that probably made things worse. These diesels really need a good run to keep the DPF happy. After I got the sensor replaced, I took it for a proper 30-minute motorway run to clear everything out. One thing I didn't mention before, while waiting for the repair, I switched to premium diesel and it seemed to help a bit with the symptoms, though it wasn't a fix obviously. Might be worth trying if you're still using it before getting it to the garage. Hope this helps! Let me know how you get on with the sensor check. These Vauxhall diesels are generally solid engines once you sort out these niggly sensor issues. Cheers, Mike

Thanks so much for all the detailed info. Really appreciate you taking the time to share your experience. That's interesting about the premium diesel, I'll give that a try tomorrow. I've got an appointment with my local Vauxhall specialist next Tuesday to check out the sensor. You're right about the short runs, I'll try to get some longer drives in once it's fixed. Your advice has definitely helped calm my nerves about this whole situation. Was worried it might be something major, but a sensor replacement sounds much more manageable. I'll update you once I get it sorted, hopefully with some good news! Thanks again for all your help! Cheers!