Land Rover Discovery's Cooling Crisis: Fix or Trade?

Hey there! I had a similar issue with my 2011 Land Rover LR4 last year. The symptoms you're describing match exactly what I experienced, persistent overheating and that annoying check engine light. Initially, I also thought it was just the temp sensor, but when my mechanic checked it out, turns out the main wiring harness connecting to the ECU was corroded and had some loose connections. This was causing false readings and making the cooling system go haywire. The fix involved replacing part of the wiring harness and cleaning up the connection points. It wasn't a quick fix, took about two days at the shop, but it completely solved both the overheating and the check engine light issues. While it wasn't cheap, it was definitely a serious problem that needed immediate attention to prevent engine damage. I'd strongly suggest getting it checked soon, electrical issues with the cooling system aren't something you want to ignore. These symptoms won't fix themselves and could lead to bigger problems if left unchecked. Hope this helps!

Thanks for sharing your experience! That's really helpful information about the wiring harness, I'll definitely have someone check that. I'm going to take it to a shop this week just to be safe. Just curious, do you remember roughly how much you ended up paying for the repair? Also, has everything been running smoothly since then, or have you noticed any other issues pop up?

Hey again! Good to hear back from you! Since my last reply, I actually took my LR4 to the mechanic and had the coolant temp sensor fixed. The main issue turned out to be much simpler than my previous wiring harness problem, it was just a faulty cable connection to the sensor. They charged me 95.00 € for the repair, which was way less than I expected after my previous experience! I'm happy to report that since getting it fixed, my Discovery's been running like a charm. No more overheating issues and that pesky check engine light has stayed off. Such a relief! It's amazing how something as simple as a bad connection can cause so much worry. This was definitely a much better outcome than my previous wiring harness saga. If your symptoms are similar to what mine were, hopefully you'll be as lucky and it'll just be something straightforward like a sensor issue. Keep us posted on what you find out! Always good to share these experiences so we can all learn from each other.

Thanks so much for the update! I finally got around to taking my Discovery to a mechanic yesterday, and you won't believe it, it was actually a combination of issues. The coolant temp sensor was definitely shot, but they also found a small leak in one of the hoses. Total bill came to about 180 for parts and labor, which honestly isn't as bad as I was expecting. They changed both parts and did a thorough flush of the cooling system. I've driven it for a few hours since then, and it's running so much better! The temperature gauge is staying right where it should be, and that annoying check engine light has finally gone off. The mechanic I found was really great, took the time to explain everything and even showed me the old parts. Such a relief to have this sorted! Thanks again for sharing your experience, it really helped me understand what I might be dealing with. I'll definitely keep an eye on things, but for now, I'm just happy to have my car running normally again!