Day by day
Since the R14 and R18 have been on the roads for 23 and 21 years respectively, various weaknesses have been observed.  The following is a list of weak spots as complete as possible, so that you can keep your vehicle in good condition and check vehicles out before purchasing. 

Renault 14 runs... and rusts!
Body. No secret here, the steel sheets of the seventies and early eighties were particularly prone to corrosion, the reason being that continuous industrial unrest in the Italian steel industry led to stockpiles being left in the open air awaiting resumption of work. Unfortunately, the rusting of the steel did not prevent it from being exported! The rust prone vehicles were at the time not even guaranteed for perforation (or rust proofed either!).  The R14 was no exception with lower doors, rear suspension mountings, inner and outer wings, bonnet and tailgate.  This litany of poor build quality explains why so few models are seen on the roads today, especially in coastal districts.  If you have a well maintained model, preserve it as it should go up in value one day.
Engine. The owners are unanimous, R14 run very well... between breakdowns!  The unreliability of the 14 perhaps played in their commercial failure.
Who said "the usual driving position of R14 owners"?

My data on the 14 are incomplete... I'm waiting for your testimonies. Write to me !

Renault 18: an engine... 
Is the 18 a monster of robustness? One could be tried to affirm it, so much the engines of this one exceed by far the average reliability of the time. Thus, it is not rare to see gasoline engines reaching  the 200 000 kilometers without a problem, while Diesel models pulverize records (see the endurance page). However, a solid engine does not make a reliable car, and R18 rusts as much as R14 in its category. 
A 18 (mine) being restored. Yes, it runs now !
Body. If bottoms of case, well-protected, seem rather not very sensitive to corrosion, the passages of wheel, and particularly the left back, are decorated very quickly revealing bubos of a corrosion perforating in the sheet folds. A failing evacuation of moisture in the doors results in a nibbling of bottoms of gates, being able to go until the rupture. Prudence thus. If cockpit seems enough saved (for those who thought of maintaining the joints rubber of the doors), the trunk and the bottom of this one can wipe the underhand attacks of rust, particularly under the tank of the trucks. The fault falls about it on the joint of often failing trunk. The bases of the entourages of front and back windshield, the lower part of the cap as well as the notch of the rod of support of the cap are also to supervise closely. Additional problem of body, the metal part which retains the door of the conductor at the time of the opening can release in the event of blow of  wind or violent opening. Result: a folded door and a nest with additional rust. Have fun to observe R18 in the street, you will see that 98% carry the traces of this forced opening! More classically, the vat which supports the battery is prone to attacks of the acid escaped of the pile. If the problem is not dealt with in time, it is all the skirt before which will disaggregate in the medium term, with expenses of body out of matter for a model of this value. Lastly, how not to evoke the trunk and its system of whimsical fastener (especially after the restylage of the year 1984), which is worth with the owners a beautiful fright (the spring of tension of the trunk releases abruptly in a detonation dries). If paintings are not directly causes some in the problem of body, they less were not during the first years of an average quality. Tarnishing, even pure and simple disappearance for the hues Bordeaux wine and red of the Eighties! A blow of polish is not enough often anymore to give them of balance. The " turbo " stickers of the models of 84-86 do not resist time either. Engine. Of a simple and tested design, the engines gasoline are in the unit reliable. Be vigilant in the event of overheating, a circuit coolant in good condition avoids breakdowns of cylinder head gaskets. At the end of the production, a defect of the stoppers of the mud of expansion also could cause incidents. Renault knows this defect and carried out replacements in the past. The diesel engines are as for them extremely robust. Indeed, the 2 068 cm3, assembled into atmospheric on the 20, 21, 25, Traffic and 20, 21, 25, 30, Espace 1 and 2, Trafic and... Safrane into turbo, is with the 18 opposite lightest the cases than it had to move, from where an increased reliability. Attention however with the assembly of the injection pump: if Bosch does not pose any problem, the Roto-Diesel knew some defects. When it is known that today, the price of this part in nine exceeds the monetary value of the last 18 GTD of 1986... The regular maintenance of the circuit of injection (a taring of the injectors can save 200 km of autonomy!) condition the good health of the engine, and, especially, a passage without concern with anti-pollution controls of the technical visit and the police forces.
Mechanical parts. The 18 knows some weaknesses of use, which require regular controls. Thus the suspension springs back seem rather fragile (case of rupture). If the car leans on a side, do not seek  further. More disturbing, the Cardan joints of diesel transmission of the models, under-dimensioned, suffer to transmit the high torque to the wheels. Their lifespan (less than 40.000 km) feels some. The endurance of  the muffler seems correct. The clutch can last 300.000 km, the suspensions accept 80 000 km (think of providing you in original parts). Nothing to announce to my knowledge on the silent-blocks. The pipes of heating and the durits should not pose problem if they are regularly controlled. 
Above: burst of the gear boxes assembled on gasoline-powered 18s.
Cockpit. In addition to affaisement from sat seats, rather normal on vehicles of this design and this age, R18 suffer from a fast wear of saddlery on the basic models, equipped with cloth, less fast on the models " of luxury " out of velvet. Also to announce, the discolouration of the trimmings of gates and a marked wear of the fitteds carpet not protected from groundsheet. The management report is decorated of a plastic rod whose coating imitation chromium often fades away. As for the higher part of the visor of the instruments (at least for the first version, 1978-1983), it is prone to cracks and resists the ultraviolet rays very fairly. The side ventilation ducts are not great solidity. Let us underline all the same that the cast solid design of thefirst instrument panel avoids in R18 the majority of the " nightingales " which had with the vibrations still seen (and heard) in R25. If the pull knobs of heating resist, do not force and lubricate the sheaths after disassembling of the central console: the plastic plate which supports the stops would not resist your  efforts a long time. The vats glove box of the doors before are not formidable quality, and it happens that an  awkward kick takes down them bonnement all of their support.
Mitja Jaksa tells us more :"On the first series of 18's there is a problem with window mechanism. After 100.000+ km joints become loose and the effect is that you cannot close the window entirely - there is about 0.5 cm gap between window glass and door frame. You must then try to tilt the glass with one hand and at the same time turn the lever to close it - quite awkward. I've talked to a mechanic who owned 2 R18 (still owns one) and he said that he had exactly the same problem and that it has to be factory error."

Electricity. The 18 is Renault of the Seventies... what means some electric troubles. Especially problems of mass due to corrosion (it will then be enough for you to connect a wire (-) directly to the battery), but also some tired engines of windscreen  wiper, exhausted starters and failing electric panes. The alternators have sometimes imaginations of their regulator. The blower of heating squeaks, is seized up before releasing. The bulbs of the rear lights are driven on printed cards sensitive to corrosion, from where an operation sometimes diverting. A passage to  the abrasive cloth should solve the problem at least temporarily. The bulbs of the management report do not  suffer too much from breakdowns. On the other hand, those which light the switches of the central console do not last a long time. Buy bulbs in advance if you are a maniac! The rear window can not be more de-icing. That often comes from the switch of the management report (eh yes!). In general, these failures occur with already sizeable mileages, it is true. Provide with fuses in advance, and say you that you did not buy a large German car all the same...

You know some more, wish to bring a precision? Do not hesitate to write to me.

© 1998-2001 Tangi Quéméner, all rights reserved on original articles.