Thread: Mystery in the Border Ranges

We went out for a drive yesterday to the Border Ranges National Park. Unsealed roads, nice and bumpy and a healthy coat of mud on the Disco now. The weather was cool and misty.

On the way down the hill, I noticed that the temperature gauge was as low as it could be, as if it were an electrical problem or there was no water flowing past the sender unit. Assuming a hose had gone, I stopped immediately. I opened the bonnet and found that the engine was not overheating. The header tank was cool to the touch, as were all the hoses. The hoses were squidgy as if there was no water pressure. There was a slight smell of radiator water but no sign of any leaks. I didn't open the header tank as I know how dodgy that can be.

Since we were going downhill and the engine wasn't overheating, I carried on for a few k's and, gradually, the temperature gauge headed back towards normal. We stopped for our picnic at the Border Loop and the temperature was normal. The header tank and hoses were hot to the touch and there was pressure. I drove home with no issues whatsoever.

Checked the water level this morning and it hadn't lost a drop of water! What happened? Could the cool and misty weather have made the engine run that cold?

Originally Posted by Tank

Last Winter, travelling down the Clyde Mt. (Kings Hwy.) in my 300TDi Disco towing a car and trailer, 2nd. gear (auto, High range) my Dash mounted EGT gauge dropped to 39 degrees C, ambient air temp was around 10C, Regards Frank.

Not sure what vehicle/engine the op has but when offroading on slow downhill tracks in cool weather at night my tdi gauge sits on the first segment above cold, then when we get onto the flat or start to ascend it starts climbing back to about a needle width below centre.
This is how i know my cooling system is working correctly.