Defender Diesel Drama: Swirl Flap Issues & Power Loss?

Hey there! Car enthusiast here with some experience working on diesels. I had a pretty similar issue with my '07 Discovery diesel last year, sounds exactly like what you're describing. Mine was showing the same symptoms: power drops, rough idle, jerking, the whole nine yards. Took it to my regular workshop and yep, it was a broken swirl flap. These things can be a real pain on diesel engines! Cost me about 865 Euro to get it sorted, but it was worth every penny because the car runs like new now. They had to replace the entire intake manifold assembly because of the broken flap. Quick question, have you had a diagnostic scan done yet? Also, how many miles/kilometers are on your Defender? Would help to know the engine size too. There are some differences between the various diesel models that might be relevant here. By the way, if it is the swirl flap, don't wait too long to get it fixed. Those broken bits can get sucked into the engine and cause way more expensive damage.

Thanks for sharing your Discovery experience! My Defender has 152762 KM on the clock, with the last major service done about 3 months ago. Haven't gotten around to the diagnostic scan yet, but planning to do it this weekend. Really hoping it's just the swirl flap and nothing more serious. The symptoms started pretty suddenly during my last off-road trip. It's a bit concerning that yours needed the whole intake manifold replaced, guess I better brace my wallet! Were there any warning signs before yours completely failed?

Hey again! Thanks for the follow-up. Yeah, these swirl flap issues can sneak up on you! Actually, thinking back to my Discovery, there were some subtle signs I missed before it got really bad. Started with occasional hesitation when accelerating, especially on cold mornings. I just brushed it off as nothing serious, big mistake! Since you mentioned yours started during off-roading, that's pretty similar to how mine really kicked in, was doing some rough driving when it suddenly got worse. The vibration got really noticeable and that hissing sound became impossible to ignore. With your mileage being pretty close to what mine was (mine had about 148000 km when it failed), it's definitely in the typical range for these issues. The fact that you had a recent service is good, but these swirl flaps aren't usually part of regular maintenance checks unless specifically requested. Quick tip from my experience, when you get that diagnostic scan, make sure they check the actuator signals too, not just the error codes. My mechanic caught some inconsistent actuator readings that confirmed it was definitely the swirl flap system before they opened everything up. And yeah, better start saving, these repairs aren't cheap! But honestly, it's worth fixing properly. I tried ignoring it for a while and it only got worse. At least now my Discovery runs better than ever! Let us know what the scan shows up!

Really appreciate all that detailed info, especially about the actuator signals! That's exactly the kind of real-world experience I was hoping to learn from. I'll definitely mention that to my mechanic when I take it in for the scan. Interesting that you noticed those early warning signs, now that you mention it, I did have some occasional hesitation on cold starts, but like you, I just ignored it. Your Discovery story is making me feel better about this whole situation, at least I know I'm not alone in dealing with these problems! I've already started setting aside some money for the repair. Better to fix it properly now than risk more expensive engine damage later. Will definitely update once I get the diagnostic results. Thanks again for all the help and sharing your experience, it's been super useful!