Defender Hybrid Nightmare: Multiple System Failures

Hey there! I've got some experience working on hybrids (some experience level here). I actually dealt with similar symptoms on my 2020 Range Rover Sport PHEV, real close to your Defender. When mine acted up like that, it turned out some vacuum hoses were deteriorated and needed replacement. The symptoms were almost identical, engine light, power issues, and that nasty jerking during acceleration. Got it fixed at my regular workshop where I know the guys well. They found the problem pretty quickly, replaced the hoses, and everything went back to normal. Cost me about 175 Euro. Before jumping to conclusions though, could you share: How many miles/kilometers on your Defender? When did these symptoms first start? Any unusual sounds when idling? This info would help compare our situations better. Those symptoms could point to different issues in different cases.

Thanks for sharing your experience! I've got 90775 KM on the clock, and my last service was just a few months back. The symptoms actually started showing up about a week ago, pretty suddenly. And yeah, there's definitely a weird rattling noise when idling, kind of sounds like marbles in a can, if that makes sense? I was hoping it would be something simple like your vacuum hose issue. It's really helpful to hear about similar cases, especially with another JLR hybrid. I might get it checked at the dealership since it's still under warranty, but wanted to get some real-world insights first. Did your workshop mention seeing this often with hybrids?

Yeah I totally get what you're going through! When you mention that marble-in-a-can sound, it's really different from what I experienced with my vacuum hose issue. Mine was more of a whistle-y sound. That rattling noise you're describing actually reminds me of another problem I had with my Range Rover about a month after fixing those hoses. Turned out I had a failing fuel injector, and the symptoms were super similar to what you're describing. The rattling noise was the big clue that made my mechanic check the injectors. In my case, one injector was clogged and another was leaking slightly. That's what was causing the power loss and that horrible jerking during acceleration. Since you're still under warranty, definitely get it checked at the dealership. My workshop guys told me they've been seeing more hybrid-specific issues lately, but honestly, a lot of these problems are common to both hybrid and regular engines, especially anything fuel system related. Just a heads up, when they fixed my injectors, they also cleaned the entire fuel system. Made a massive difference. Total job took about a day, but since you're under warranty, you won't have to worry about the cost like I did. Keep us posted on what they find, I'm really curious if it turns out to be similar to what I experienced!

Thanks so much for the detailed follow-up! That's really interesting about the fuel injector, actually makes a lot of sense with the symptoms I'm experiencing. The rattling sound being different from your vacuum hose issue is a useful distinction. I've just booked it in at the dealership for tomorrow morning, and I'll definitely mention the fuel injector possibility to them. It's so helpful hearing from someone who's actually dealt with similar issues in their hybrid. You're right about using the warranty while I've got it, might as well take advantage of that! I was getting worried about potential huge repair bills, so that's a relief. I'll make sure to ask them about doing a full fuel system cleaning too, seems like a smart preventive measure. I'll post an update once I get the diagnosis. Really appreciate you taking the time to share your experience, it's made me feel a lot more informed going into the dealership appointment!