Defender's Coolant Loss & Warning Light Mystery Explained

Hey there! I had similar issues with my 2003 Land Rover Discovery TD5. The symptoms you're describing remind me of what I dealt with last month. Initially thought it was just low coolant, but turned out the water pump's electrical connector was corroded and making poor contact. The mechanic found that the connector pins were damaged, causing intermittent communication failures between the pump and control module. This explained both the temperature warnings and check engine light. The repair involved replacing the entire wiring harness for the water pump and cleaning the connection points. It was a serious issue that needed immediate attention because the pump wasn't getting proper electrical signals to maintain correct coolant flow. If left unfixed, it could've led to engine overheating and potential damage. My advice: get a second opinion from a Land Rover specialist. These symptoms are too specific to ignore, and it's better to address it properly rather than risk engine damage. Hope this helps!

Hey, thanks for sharing your experience! That's really helpful as I've been worried about my Defender. The water pump wiring issue makes a lot of sense given the symptoms. Quick question, do you remember roughly how much you ended up paying for the repair? Also, has everything been running smoothly since the fix, or have you noticed any other quirks pop up? Just want to know what I might be in for when I take it to a specialist. Thanks again!

Hey again! Just wanted to update you, yes, I paid exactly 155.00 € to get the cable connection and pump plug fixed, and it was totally worth it! Since getting it sorted by the mechanic, all those annoying error messages between the control devices have completely disappeared. Such a relief! The best part is my Discovery has been running like a dream since the repair, no more temperature warnings, no check engine lights, and the coolant level has stayed exactly where it should be. It's been about 6 weeks now, and I haven't noticed any other issues pop up. I know these old Land Rovers can be a bit finicky sometimes, but once you get the right diagnosis and repair, they're solid machines. The specialist I went to really knew their stuff, made me feel much better about the whole situation compared to my previous mechanic experiences. Let me know how it goes with yours! Always happy to share more details about my experience if you need them. Cheers!

Thanks so much for all that info! Just got back from the mechanic actually, and you won't believe it, it was almost the exact same issue! The wiring was shot, and they found some corrosion in the connector too. Bill came to a bit more than yours, but honestly, I'm just happy it's fixed. Took it for a test drive today and what a difference! No more warning lights, temperature's staying steady, and the coolant's not going anywhere. The engine's running way smoother too, which is a bonus I wasn't expecting. Really glad I asked here before going to my usual mechanic. The specialist you mentioned going to made me look for one too, and they knew exactly what they were doing. Spotted the problem right away. Thanks again for helping me dodge what could've been a much bigger headache. These old Defenders definitely keep us on our toes, but they're worth the trouble! Catch you around!