The variator is a wellknown problem on the twinspark 16v engines, and it is a quite costly repair.
I spoke with my alfa mechanic the other week however and they have started using Bilstein engine flush
http://www.engineflush.com/pages/engine.html
with good results, what they do is that they hook the machine up to your engine and flush it clean with a cleaning fluid, it takes like 15-20 min, and then of course they fill it up with new oil and filter and so far it has worked really good on those diesel sounding variators.
So check if there might be anyone in your area that have this sort of equipment, and you could save alot of cash.
/mopar