Niall's 2000 306 XS A.K.A Craig

[C.A.R.]

My 1.8 had chronic oil-burning issues, turned out to be the oil control rings. Have you checked that this isn't the problem on yours? Don't know how much easier it is to do with the head on/off. I know you can test oil seals on valves by pouring a little petrol into them, maybe it's the same with piston rings? Otherwise it's a leakdown test, which looks like you might need specialist equipment.