In the past few days my wife's Alfa 155 (1997, 2.0 16v) has been consuming coolant. Not a great amount, about 0.5 litre every 200 miles. I can't find any leaks, there are no other symptons (eg no oil in water, water in oil, temps & pressures all look normal etc). The engine is as sweet as ever.
The car has done 90,000 miles and is covering about 25k a year, hence I really need to find the problem before breakdown. What is the most likely source of the leak?
I suppose it could be the waterpump, but I haven't found any visible signs with the limited access.
If it is the waterpump - is this a difficult/expensive job?