BMW Z3 has excellent rustproofing, meaning any significant corrosion should not be an issue, this is helped by the fact the front & rear bumpers are made of plastic.
Even any areas usually affected such as wheel arches, door sills and floor pans, should not be affected by any corrosion, so if you see any rust bubbles, its clear the car has probably been neglected / repaired badly. Either way, it`s best avoided.
Despite the BMW Z3’s affordability, it`s tended not to be the appeal to the hooligan driver. Most examples are lovingly cherished, especially that the car now is a modern classic.
You`ll need to check though for any evidence of crash / damage, such as a rippled inner wing or a boot floor that isn`t not quite straight.
The other areas of concern include the bodywork items around the boot lock, and door mirror bases, another favourite is the mountings for the rear differential as well as the rear subframe.
Another area worth checking is the boot for any evidence of water leak / ingress. Often the boot seals perish, water gets in it will collect in the side of the boot.
The cloth folding roof is very simple to use. BMW use an electro-hydraulic setup, its mechanism is quite common, but it`s not universal. The problems are quite rare, with the covering and the frame, but do check the general overall condition, and do make sure that it goes up as well as and down very smoothly. What could be an issue is a damaged or a perished seal around any side window or along the top header rail; if any of these leak, the BMW interior will nearly always be damp. Inspect the plastic rear window, this can go very opaque; there never was a glass option here, but you can revive it with suitable plastic window restorer / polish. A new roof is rarely needed; but with labour, replacing the hood typically is upwards of £1500.
Starting from 1998, there was actually an aluminium hard top that was offered as a BMW accessory. Very costly when new, needless to say rare, it does make the BMW Z3 much more usable for the winter, but the BMW cloth roof is well weatherproof and is generally a problem free item.
The BMW Z3 came with an 8v four cylinder (1.8 litre), a16v four cylinder (1.9-litre) or the 24v six cylinder (2.0l, 2.2l, 2.5l, 2.8l, 3.0l and the 3.2-litre) fuel injected engines. All do need to run on unleaded petrol only, and all easily will take 200,000 miles if they`re properly maintained.
The six-cylinder engine will provide much more muscle, but the four pot units do tend to be a bit more reliable. The European BMW Z3s got the all alloy straight six, but the US editions got the cast iron cylinder block. Some of the early Euro BMW powerplants actually featured Nikasil coated block liners that could get be damaged by the high sulphur petrol. From late 1998, steel bore liners were used instead, ending the problem.
BMW 6 cylinder engines have a plastic water pump; this can often struggle to cope, so do look for any evidence that the engine is getting hot or has overheated. With the BMW 4 cylinder engines, any problems are most likely to be a faulty Lambda sensor. Look to see if the EML illuminates, it’s about £180 fix. Other issues are a rattle from the timing chain (£500 to £650 to fix) or simply a failed thermostat. So if the engine does take ages to reach temperature, then assume that a new thermostat is required – £75-100 to sort it.
The BMW M Roadster and the Coupe did come with an iron cylinder block, some of suffered from a substandard bigend bearing caps that failed, wrecking the engine. Affected engines surely should be fixed by now probably under warranty.
The BMW M Roadster and the Coupe featured the VANOS variable valve-timing, on the early cars this gave problems. It’ll cost roughly £2500 to fix, so do listen very careully for any grumbling noise from the engine when you`re accelerating, and on the over-run, with a hesitation or a flat-spot.
Aside from the BMW M editions, all Z3s had a choice of Getrag 5 speed manual or the THM 4 speed automatic gearbox. No weak spots really as such but, still make all the usual checks. Lookout for any clutch slip, do this by accelerating hard through the gears, and then watch if the revs actually rise with out the car gaining any speed (new clutch will cost £250). The headache dual-mass flywheel will fail – do listen for any rattle when you`ve started and stopped the engine. Genuine BMW costs are over £800, from LUK it`s under £300. But labour is about £500, sensible to replace the clutch assy too.
STEERING & SUSPENSION
All BMW Z3s have the speed sensitive hydraulic power steering system; this makes the BMW Z3 an absolute delight to drive. It’s a very reliable system, but it’s worth ensuring it has no leaks, and the gaiters and the track rod-ends are in very good condition. Surprisingly, everything is still available, unless you`d need a whole new p/steering system.
Although many road testers had complained about the BMW Z3’s very unsophisticated suspension, in reality unless you actually thrash your classic BMW at every given opportunity, the standard BMW set up isn`t likely to disappoint you.; the BMW M cars received a very heavily revised suspension system that is far more adept. So while there are the MacPherson struts at the front, the rear has semi trailing arms, with coil springs and the telescopic dampers, with the anti-roll bar at each end. The dampers wear out, but much more likely to be worn are the rear shock absorber mountings, this is given away by quite a rattling when driven – you`d expect to pay about £85 to sort the problem.
Most BMW Z3s are pretty much as they`d left the factory, oddly though some owners feel they can tweek and lower and stiffen the suspension. Be very wary of any such cars, they`ll drive like a pig and be very uncomfortable at the best – at worst they might be suffering cracks in the BMW floor pan along with an increased scuttle shake.
WHEELS & BRAKES
BMW Z3s have nice alloy wheels, which suffer from corrosion and of course kerbing. Refurbs cost £75 to £100 a wheel; you could buy aftermarket wheels instead, or BMW Z4 wheels, they go straight on. BMW Z3s sporting the ugly non-factory wheels along with cheap seriously low profile tyres are going to ride badly, so beware.
TRIM & ELECTRICS
Most BMW Z3s were fitted with gorgeous leather trim, some only have cloth. Both actually wear quite well, but do check the condition, the outer edges on the seats, just where the seatbelt rubs.
BMW electrics really aren’t that complicated, but still they`re still more complex than you might think, they`re more complex than the older BMW classics. Expect reliability though, but if anything in the system looks like it’s been messed with (aftermarket stereo and security systems are favourite) there could well be a problem. The most likely that`ll give grief is the BMW electric-seat adjustment, not all the cars have it. Do make sure that you get 2 keys if you buy a BMW Z3. Because If you were to lose the sole BMW key, you will need to get everything reprogramed, that`ll cost hundreds.