i currently own a clio 1.2 16v expression (very similar to what your looking at) and its a great little car, id recomend you join
www.cliosport.net for any advice when buying
heres a section of the common faults article posted on the site...
1.2 16V problems
Note
The 1.2 is a bit of a problem engine it was built to a budget rather than a quality, although its not a bad engine and will probably outlast the car.
Throttle body is electric it can get blocked particularly if you have an aftermarket air filter etc. To clean it you have to remove the engine cover along with the 6 bolts holding the manifold on and turn the manifold over since the throttle body is under neither the manifold as such.
Noise
Between 0~10 MPH a clicking sound can be heard. This could be a faulty ABS sensor in the wheel. Its a reasonably common problem and covered under warranty.
Mayonaise like material in the oil cap.
This is a common problem on any cars, which only do short journeys, and the 1.2's suffer a lot it should be a worrying sign for an engine but it seems to be a common thing on the 1.2's and not such a great worry.
Oil burn
The specification for Clios engine running oil is 1 liter per 1000km (or 600 miles) is deemed as acceptable. That's a lot of oil but so long as it's a burning less than that Renault can refuse to help as it's in tolerance. Its unlikely Renault wouldn't help if you were burning that much oil as that's a significant amount, but there no reason they have to. So remember to check the oil ever week.
Most engine problems are
1) Pencil coils, its a very common fault on later 16v renaults. If you have an earier age 1.2 it could be the lead and coil pack - part number 8200084401 £49.20 also it could be the TDC sensor 7700101969 £17.65
2) Defective Spark Plug/plugs. Its a Known problem will be doen under warently (new plugs). There's a tech note out about it. Also the 1.2 seems to go throught plugs much quicker than they are before there chnaged as part of the service.
3) Faulty Upper Engine loom and/or Map sensor. Possibly having to replace either Map sensor and/or upper engine loom. There's a tech note out about it.
4) Injection Computer Map. Reprogram Injection Computer to cure lumpy idle/stalling etc. There's a tech note out about it.
5) Defective Injector. Change individual faulty injectors. Takes time to find out if it is this. This isn't a technical note though about this issue.
5: Damaged Upper engine loom. Where the anti tamper cover on the loom connector at the rear of the engine moves and chaffs the cable. So causing poor running stalling etc. Renew the loom and apply a rubber sleave to the cover to stop it happening again.