Defender Diesel Woes: Boost System Warning Signs

Hey there! I have some experience working on cars, and this sounds very familiar. I had similar issues with my 2019 Land Rover Discovery diesel last year. The symptoms were exactly like yours, black smoke, power loss, and that annoying whistling noise. After checking with my trusted mechanic, it turned out to be a faulty waste gate valve. The whole repair, including parts and labor, set me back about 860 Euro, but it fixed all those issues completely. My Range Rover-specialized workshop had to order the part and completed the job in about a day and a half. Before jumping to conclusions though, could you share: How many miles/kilometers on your Defender? When did these symptoms first appear? Any recent maintenance done? This would help confirm if you're dealing with the same issue I had. These symptoms can sometimes be related to other turbo components too, so it's worth double-checking.

Thanks for the detailed reply! I've got 121994 KM on the clock, and these issues started showing up about two weeks ago. Actually just had my regular service done last month, and everything seemed fine until now. Your waste gate valve situation sounds spot-on with what I'm experiencing. Were you also getting that slight hesitation when accelerating? It's good to know it was a relatively straightforward fix for you, although not cheap! I'll definitely mention this to my mechanic when I take it in. Did you notice any warning signs before it completely acted up? Just curious if I could have caught this earlier. Thanks again for sharing your experience!

Hey again! Yes, absolutely, I had that exact same hesitation during acceleration. It was super annoying, especially when trying to overtake! And honestly, looking back, there were some subtle signs I probably missed. About a month before everything went haywire, I noticed a slight drop in performance and occasional whistling noise, but I brushed it off thinking it was nothing serious. Big mistake! Your mileage is pretty close to what mine was when I had the issue (I was around 115000 KM). And the timing after your service is interesting, sometimes these problems can start showing up when other parts are disturbed during routine maintenance, even if everything's done correctly. One thing I didn't mention before, after the waste gate valve was replaced, my fuel economy improved significantly too. I hadn't even realized it had been gradually getting worse until I got it fixed! Quick tip from my experience, while they're in there fixing the waste gate, have them check the actuator and surrounding hoses too. My mechanic found a small crack in one of the hoses that could've caused problems down the line, so I got that replaced at the same time. Saved me another potential headache! Let me know how it goes when you get it checked out. I'm curious if it turns out to be the same issue!

Thanks so much for all that extra info! It's super helpful to know about those early warning signs, I definitely won't ignore any whistling noises in the future. And that's a really good tip about checking the actuator and hoses while they're working on it. I'll make sure to mention that to my mechanic. Interesting what you said about the fuel economy too, now that I think about it, I've been filling up more frequently lately but didn't make the connection. It makes total sense though. I've already booked the car in for next week, and I feel much more confident going in armed with all this knowledge. I'll definitely let you know what they find. Really appreciate you taking the time to share your experience, it's helped put my mind at ease knowing this is probably fixable without any major drama!