The most desirable standard AX spec wise is the AX GTi, it comes with uprated 4 stud suspension and the most powerful engine fitted to the AX as standard. The ax was revised in 1991 so there are two choices you can either buy the Mk1 the Mk2. The MK2 was released mid 1991 and has has as slightly better brake set-up, an improved dash, more rounded boot lid and bumper, clear front indicators and a stronger gearbox. Everything else is either the same or very similar to the MK1. The easiest way to identify a MK1 over a MK2 is the mk1 has a very boxy dash
The average price for AX's now ranges from £0 to £800 in standard trim. Modified ones can fetch more but usually only ones with engine conversions especially ax vts conversions are sold for more than £800
All the above prices are a rough guide, some special cases such as immaculate AX's may fetch more than suggested. You will find that the owners club prices are usually cheaper than the ones found on the auto trader.
Below is a list of common faults with AX's. This does not cover all faults, just the ones that you should probably check along with the normal checks you do when buying any car
The main areas for rust are
Behind the headlights Standard for ALL ax's to rust here, its an MOT failure as it is within 30cm of the suspension. This can turn out to be a good bartering point, fixing shouldn't be too expensive as it only requires having the rust ground out and a metal plate welded in.
Filler cap Sometimes these can rust right through, sometimes not at all. Attention should be paid to the filler neck and surrounding areas for rust.
Boot floor If the boot has been leaking and the carpet has lay on the floor wet it lets the rust spread a lot quicker than usual. Check around the edges for holes.
Bodykit If the car has the standard body kit fitted take some time to look at the lip of it all round the car, any rust bubbles indicates that the arch is much worse under the kit.
Rear 1/4 Just above the Bumper : Sometimes the bumperbar mount and rear 1/4 can rust, if you find a car with this remove the light cluster and check inside to see how far the rust has progressed
Behind the Rear Lights : Very easy to remove them so its worthwhile doing.
Rear Window Edge : If the rear lights are out you can just about see past the seatbelt and along the bottom of the window (will need a torch). Sometimes you can get rust in this area too. The giveaway is if theres spots of rust on the body under the rear window on the outside, this is 95% of the time not surface rust.. Its coming from the inside out.
Paid members can view a more detailed guide on rust Here
Front Seat Mountings If either the drivers or passengers seat rock and seem to be loose around the gearstick area its possible they have ripped the bolt from the floor. This is an MOT fail but isnt too tricky to repair. Requires removing the carpet and having the nut welded back in
Leaking Interior Light Quite a common fault that they drip water in, its a simple fix. Remove the aerial and put some grease under the mounting.
Rattles Come as standard in any Citroen AX, it adds character!
Faulty electric windows / central locking Usually down to broken wires in the rubber between the shell and the door. Fairly easy fix
Seats are quite often available on AXOC for cheap and sometimes free so dont let a dirty seat put you off buying, use it to haggle!
Oil Leaks Its very common for the TU engine to leak oil from the head gasket around the front of the engine, cars that are leaking can quite often run like this for many miles as long as the oil level is maintained, however it really should have the head gasket changed. They are also prone to leaking from the rocker cover, this is an easy fix and usually only requires a new seal.
Gearbox The gearboxes are often considered the weak point of the ax and suffer quite often. On a test drive change rapidly from 1st to 2nd then 2nd to 3rd, listen out for a crunch. Gearboxes can often be found for fairly cheap but it is not a novice job to fit one. A sloppy gear change is usually the linkages.
Rear Beam Quite a common fault with the rear beam is that the trailing arm bearings fail and cause the wheels to lean (negative camber). View the car from behind and check the wheels are sitting upright and not leaning into the body. Also pull and push the wheel towards you from the side to check for any excessive play. If the bearings have failed the car will require a new rear beam.