My Uno started using a bit of water. The heat gauge shows nothing is wrong but every so now and then do I need to add about 50 to a 100ml of water. This suddenly started.
What should I look for or what should I do?

I guess the leak could be anywhere.

My last two leaks were from welsch plugs (also known as core or freeze plugs).

I have the 1100 mia, the first plug that started leaking were between the pullies, you will see the round disks pressed into the engine.

The second one were at the back of the engine above the starter and below the intake, I couldn't see them but were able to feel them and one were wet.

It was R350 to replace the first one and R450 for the second since the mechanic had to remove the starter.

If a visual check around all hoses, gaskets, core plugs and the radiator don't locate any dampness or staining, suspect the water pump. These usually only leak when rotating, and most of the leakage will evaporate as it is hot.