South Africans are so used to fine weather that they are not too concerned about their vehicles when winter arrives. Then the winds sweep in from snow-covered Lesotho, and their vehicles are not prepared.
On one of our expeditions to Lesotho, there were quite a few vehicles in the convoy and everybody was excited about the snow. As we climbed up the steep mountain pass on our way to Katze Dam, some vehicles began falling behind, so we stopped at the lookout point to wait for them.
An Isuzu arrived in a cloud of steam and a Colt came creeping up very slowly. The trip had just started and we could not leave them behind, so all the clever men started giving advice.
First, the diesel filter in the Colt was removed, and to our surprise it was filled with a jelly-like substance that looked like a Sunday lunch jelly salad. The foreign substance was emptied into a storm water gully. Then we noticed that the diesel filter was very dirty. Since we often get clogged up diesel filters on our snow expedition, I carry a few popular sizes and happened to have the correct one for the Colt.
We used the priming pump to get the jelly out of the fuel line and then fitted the new filter. When the engine was started, it sounded like a brand new one and all the power was restored.
Then we noticed a strange thing. The jelly stuff that had come out of the filter bowl was melting and disappeared down the storm water gully. We then realised that the diesel had frozen and, being oily, did not become solid but formed a jelly-like substance. With the oil filter being so dirty, the jelly was too thick to get through and the engine could not go faster than idling speed.
The lesson we learned was always to carry a spare diesel filter in our vehicle. This applies for every off-road trip, especially when you go into very cold areas.
When parking the vehicle at night when it is very cold, park it so that the wind does not come from the front. It is best to park with the front of the vehicle against a wall, or something that can stop the wind.
We then attended to the Isuzu, which had had some time to cool down. To our surprise the radiator was ice cold while the engine was overheated. It appeared that the water in the radiator had frozen solid and could not circulate through the radiator. The viscus fan had been locked and sucked the air through the radiator at full force, causing it to cool down more than it should have, so it froze the water. The owner had also neglected to put anti-freeze in the cooling system.
Fortunately the ice melted quite quickly and we could open the radiator cap.
We felt the experience should be a lesson for the owner and insisted that he put a bottle of brandy that he planned to drink that evening into the radiator. There was a lot of good-natured protest from his companions, but the brandy acted as a sort of antifreeze and the Isuzu did not overheat again for the rest of the day.
Antifreeze drives the oxygen out the water and prevents oxidisation of the parts in the cooling system. It lowers the freezing point of the water and increases the boiling point.
Be careful, though. Antifreeze is extremely poisonous and should be kept away from children.