Mileage isnt the issue Id say, as they mainly seem to get the problems from about 60-80k miles. But then again, people always sell their car for a reason...
Read the 1994 Cars & Car Conversions article on the Williams on the main Cliosport site (under articles!). That outlines the Group A pedigree of the 16v - and its later homologated special edition: the Williams.
Despite this greatness, the road-going cars can be expensive and time consuming - though not because there are any inherrent faults. Cared for cars will last very well, but those that have been repaired cheaply/not at all will cause problems. Basically, you may be in deep water outside of buying from an enthusiast - youll find the odd sunken treasure, but also a lot of monsters. Many people buy a 16v, realise they need to be loved and then sell them on with problems.
I bought what looked like a really nice example, with engine mods and leather. Despite a new engine, clutch, brakes and sound bodywork, Ive spent the best part of my spare time and money over the past two years replacing practically everything on this car.
But they look beautiful (especially with no exterior mods), make one the best 4-cylinder production engine induction roars and are damn fast. Theyre only Group 12 insurance too.
Prices amongst enthusiasts depend on condition - not age or mileage (though an extremely low mileage/young example will make extra).
The leather is well worth it, as I know - but it will add about £500 to the price. Phase2 is the spec to go for if you can: its build as much as looks. Ive got an early Phase2 (on a very late L-reg) and the doors shut with much more of a good thud than my flatmates Phase1; meanwhile, Ivegota16vs late N-reg doors close with more of a good thud than mine! (not that doors = total build of the car of course!).
The world of buying a 16v is full of perils and gems. The pricing is totally unfathomable. Throw your price guide in the bin and buy on condition. Youll see the odd 16v at £1500, but you wont be getting a premium example for that, mark my words! On the other hand, there are some real sh*tters for £4k.
I would avoid cars with big wheels (owners ask more and theyre hard on suspension/bearings) and wouldnt worry too much about high miles if the bils are there. There will be loads of cars with 60-70k miles on the market for good reason: its a very expensive mileage. If you pick up a car for a good price with 100k miles plus, it will probably give you less big bills (already done), but more annoying little jobs.
Overall, Im of the opinion that 16v owners are of the demographic that look after their cars well - enthusiasts. However, the cars are fairly maintenace-intensive, so, as ever, the care it has received thus far will usually dictate condition. Look for a big folder of bills.
What you should then be looking for then can be split into categories:
Exterior:
- Rear arch lips are susceptible to rusting, front ones are plastic so arent a problem. Rust also possible on door bottoms, around window rear quarters and boot bottom. Rear arches are now only available as an entire quarter panel - £330 from Renault inc VAT each side - so make for an expensive repair. Other body panels are surprisingly reasonable after a recent price cut.
- Front fogs (expensive) are prone to cracking due to stone chips.
- Bonnet and front bumper also prone to stone chips.
Mechanical:
N.B. due to engine size, many otherwise simple jobs on 16v/Willy are engine-out jobs.
- Cambelts must have been done before 72k (many advise a cambelt change far earlier); fairly big bill in itself and mega bill if it snaps in service.
- Diffs, gbox and clutch are all expensive jobs so check carefully. Jump off the accelerator in 2nd to see if it pops out of gear: if so, then suspect the box or the "dog bone" engine-to-subframe engine mount.
- Rear brake callipers can seize. New rear discs necessitate new wheel bearings.
- Check aftermarket exhaust mountings - often a poor fit; rumbling under load can be caused by poor exhaust manifold to downpipe gasket (cheap job, disturbing noise).
- Erratic idle commonly due to faulty throttle potentionometer or idle speed control valve (respectively a specialist job and a straight swap).
- 16v/Willy run hot, so check coolant system - hoses, rad, expansion tank, water pump, anti-percolation (if you can). Radweld works wonders with minor radiator leaks.
- Engine mounts often go - embarassing and expensive to have your engine fall out, so see if engine rocks back and forth by opening bonnet and pulling accelerator cable.
- If car has induction kit check security of air hoses - can explain erratic idle or apparent air leak.
- Steering racks and columns are common failures. The handling reaction will be a second or two behind steering input in such a case; car will also tramline and follow road too much.
- Check for snapped front springs.
- CV gaiters should be checked - manifested by clicking noise on full lock.
- Handbrake is normally not good.
- If lowered, will need new front strut top mounts sooner or later. If majorly lowered, check to see that brake pressure-regulating control valve has been adjusted at the rear - otherwise the back wheels will lock too easily. Lowering also places extra strain on front anti-roll bar mountings and bushes and the track rod ends.
Interior:
- Sunroofs leak - tough luck!
- Electric window and mirror switches are very expensive - so check them too.
- Front seat belt reels often become ineffective - especially the drivers one.
- Door handle rods in door mechanism can come loose, so that the handle wont work. A time-consuming but easy job.