Discovery Diesel Nightmare: Idle Issues & Black Smoke

Hey there! I've got some experience working on cars, and this sounds very familiar. I had similar issues with my 2001 Land Rover Freelander diesel (those symptoms match exactly what I experienced). The cable and plug on the idle control valve were shot on mine. Had the same problems, black smoke, rough idle, unusual stalling, the works! My mechanic found it pretty quickly, and it was a relatively straightforward fix. Cost me around 155 Euro total, including parts and labor. But before I share more specifics, could you tell me if you've had any diagnostic tests run yet? Also, what's your engine size, and have you noticed any particular patterns when these issues occur (like after the engine warms up or in cold weather)? I know these Land Rover diesels pretty well, and there could be a few other things to check too. Let me know those details, and I can help point you in the right direction!

Thanks for your detailed response! Yeah, my 2003 Discovery diesel (144461 KM) is showing exactly those symptoms you mentioned. Haven't done any diagnostic tests yet, but it's definitely getting worse. Just had a service last month and everything was fine then. It's actually happening more frequently when the engine's warm, especially during city driving. The shaking and power loss are really concerning. I'll definitely get it checked out by a mechanic, but good to know about the idle control valve, that repair cost sounds way better than what I was worried it might be! Did your mechanic mention any other potential causes I should look out for? Really hoping it's just the idle control valve like in your case.

Hey again! Yeah, those symptoms on your Disco sound exactly like what I dealt with on my Freelander. Since you mentioned it's happening more when the engine's warm, that's even more similar to what I experienced. Just to share a bit more about my experience, my mechanic actually checked a few other things first. There was a chance it could've been the mass airflow sensor or fuel filter, but the diagnostic test pointed straight to the idle control valve. The black smoke and power loss got really bad near the end, especially in stop-and-go traffic. One thing I noticed before getting it fixed was that the idle would sometimes sort itself out if I revved the engine a bit, but that was just a temporary fix. The stalling got pretty nerve-wracking, especially at traffic lights! Since your mileage is pretty close to what mine was when it happened (mine was around 150,000 km), I'd bet you're dealing with the same issue. Just make sure they check those connections and wiring to the valve too, sometimes it's not the valve itself but the electrical bits that go bad. Still, worth getting that diagnostic done just to be 100% sure. Would love to hear what your mechanic finds, keep us posted!

Thanks so much for all that info! That's super helpful, especially about checking the connections and wiring too. I've actually noticed the same thing with the revving temporarily fixing the idle, can't believe I didn't mention that before! The fact that your Freelander had such similar issues and mileage really puts my mind at ease. I was worried it might be something major like the turbo or injection system. You're right though, I'll definitely get the diagnostic done first. Just called a mechanic and booked it in for tomorrow morning. I'll update the thread once I know what's going on. Really appreciate you taking the time to share your experience, it's given me a much better idea of what to expect. Fingers crossed it's just the idle control valve!