Yesterday the water temp gauge on the Defender steadily rose into the red after about about 2 minutes of driving. Normally it sits bang in the middle even when towing, so this was a little odd. I stopped before it got it went fully into the red and checked the coolant in the expansion tank which let of a little bit of pressure and a few steamy wisps and that was all. After leaving it a while I drove slowly to my yard with no mad temp climb. Come to today, and after replacing the thermostat and squeezing all the pipes for blockages (it seems to run freely), I started the engine and the temperature gauge went of on it’s merry way up to the red after about 10mins of idling and some revs. Yes the vehicle was stationary, but considering it’s 1°C and Defenders are built to run at revs while at a standstill, this shouldn’t be happening.

There is no oil in the water, or vice-versa, so I very much doubt hgf. I’ve even had the valve cover off just to make sure, using the opportunity to replace the gasket and do a full oil change because Land Rover. Also the radiator is luke warm to the touch, and the silicone hose coming away from the pump and supplying the bottom of the rad is hot. The expansion tank is the same as when it first happened- hot, but not excessively.

So what are my next steps? I will assume some kind of system flush or hosepipe jobby to make sure it’s clear? Or am I looking at the water pump here?

20 year old unknown service history Land Rover valve train for your time.

And Land Rover wee.