Dave
I found that marking the level with the plastic arrow helped in determining the rate of loss. Check the two hoses which attach just above the oil filter. Above the filter is a simple oil/water heat exchanger (also used on MG Metro!!). It's a simple two hose/two Jubillee clip arrangement, and mine needed tightening, as there was a very slight leak there.
Also check the other hoses down the back of the engine. A finger under each join will show any wetness. (engine NOT running!!!!!)
Then shine a torch under the radiator when cold, and if there's a leak it will show a blob of water. The sealant I used has worked, but it took a long run before it did the job. Warming up in the garage was not enough.
