Thought I would post a reply as I finally got to the bottom of this having been down the rabbit hole. I like to think I am a logical thinker and I use tools to diagnose thorny issues for my job. So it’s really annoying that I made a simple mistake which led to weeks of pain. I first noticed an...

OK, that's good to know. I have read some research that an HG that blows around a cylinder rather than a complete failure can put more heat into the engine. Not sure why but given my running hot symptom came on unexpectedly I would say this is definitely a suspect. Thanks again!

Good to know, thanks. Did you get the weird symptoms I am getting?

Thanks all for your comments. I think it's looking like a head gasket on the way to failure. Going into Landie specialist in a couple of weeks so fingers crossed the head doesn't need skimming! Thanks again

Thanks again for your replies. The previous thermostat was working (I tested it) and still had the issue. The system has had coolant changed a couple of times - had the radiator plug off and waited for air to escape etc. so I think the system is bled OK. Not losing coolant so don't think it's an...

Thanks for your replies. The Rad is not that old. By new rad cap do you mean new cap on the header tank? How would this make a difference?

Has electric fan. No cowl. Thing is it was running fine for months and has just started with the issue. Original Defender 200TDI engine

Firstly, I know there are lots of threads on here about overheating. However, I have an unusual situation I can't get to the bottom of. My Defender 90 200TDI has started running hot on the motorway. Around town it's fine, but when pushing hard it gets to 98 degrees C (I installed a VDO sender...

Hi, Looking for some advice. New to Defender ownership. Love my Defender. However. Leaks. I have a persistent rear diff seal leak. I have replaced the seal twice and have installed a new flange. I noticed recently that the axle breather was blocked completely so have replaced that but the seal...