Had it 5 years now (got it at 36,000).
Cylinder head gone twice - this is the glass jaw of the PSA diesel family.. second time after only about 5,000 miles after first re-bore.
Heater matrix burst one time too.
Blower fan gone once, about to go again.
Rear hatch lock broken and fixed (DIY).
Mind you at 90,000 miles it's still ultra-economical.
AX is the last Citroen worthy of the name... it's quirky and well designed. Nothing can touch it for economy and with the rear seat out it can carry more than you imagine.
Will give 60mpg at 75mph on 450 mile non-stop M-way runs.
Hard to access a lot of the components since it's a nastily done switch from LHD to RHD.
If you buy a "D" make sure it's got FSH and ask about the cylinder head.
Dealer service varies.
Accommodation atrocious inside but I can't help loving it.
I bought a 1990 1.4 TGD in June with 102,000 miles. I had to have the head gasket done shortly afterwards. There's no telling how many times it was done before though.
The mechanic recommended I should have the cylinder head reground at the same time, but I couldn't afford it so gambled on just getting the gasket changed. So far it's been ok.
My main problem now is that I had an accident which damaged the front passenger side wing and front panel. I've been told by various people that the repair will cost more than replacing the car, but haven't given up yet since I've spent so much on it already. The front of the car seems very poorly built to survive accidents though. I suppose the trick is to just not crash them.
The fuel consumption really is good, but I couldn't say it's been cheap to own.