WHAT TO LOOK FOR

ROOT OUT THE RUST

Excellent rustproofing means that significant corrosion shouldn’t be an issue; the front and rear bumpers are plastic. Even the usual areas such as the wheelarches, sills and floorpans shouldn’t be affected by tinworm, so if there are any rust bubbles, the car has either been seriously neglected or repaired badly after a crash. There are a few localised areas that can corrode though, including the bodywork around the boot lock, the door mirror bases and the mounting points for the differential and rear subframe. As well as rust, the latter can also suffer from cracks if the car has been driven hard. Evidence of water having collected in the boot points to perished seals.

GEARBOX GREMLINS

Aside from the manual-only M Roadster, all Z3s came with a choice of Getrag five-speed manual or THM four-speed automatic gearboxes. There are no weak spots as such, but check for wear or damage, including clutch slip and failed dual-mass flywheel. A genuine BMW flywheel costs more than £800, but the same part from LUK is less than £300, meaning a specialist can replace the flywheel for £800 all-in. Also ensure that the car doesn’t jump out of top gear; if it does, a gearbox rebuild is in the offing, although fitting a decent used transmission is a much cheaper option. Expect to pay around £450 for a specialist to do this job for you.

SORT THE SUSPENSION

All Z3s have hydraulic power steering. It’s normally reliable, but check for leaks and that the gaiters and track rod ends are intact. Road testers complained about the Z3’s unsophisticated suspension when it was new, but the standard set-up is unlikely to disappoint unless you thrash your classic at every opportunity. M cars got a heavily revised system that’s far more adept. Dampers can wear out, but worn rear damper mounts – given away by rattling as the car is driven – are more likely; expect to pay £85 per side to fix the problem. Most Z3s are kept standard, but some owners lower or stiffen the suspension, which can make the ride uncomfortable. WORDS Richard Dredge PHOTOGRAPHY Magic Car Pics

HOW’S THE INTERIOR?

Most Z3s came with leather trim, but some have cloth. Both wear well, but check the condition of the outer edges of the seats, including where the seatbelt rubs. The electrical system isn’t as complicated as you might think, but may not be DIY-friendly for everyone. You can expect reliability, although if the system has been ineptly butchered (particularly with aftermarket stereo or security systems), expect problems. The electric seat adjustment is most likely to give trouble, but not all cars have this. Make sure you get two keys with your Z3; lose the sole key and you’ll need to have everything reprogrammed, which will cost hundreds.

ALLOY WHEEL OPTIONS

Refurbishing kerbed or corroded alloy wheels normally costs £75-100 per wheel. Alternatively, you could fit aftermarket rims, though quality varies wildly and ultra-low profile tyres ruin the ride. Bang goes your originality, too. Later Z4 wheels will go straight on to a Z3, however.

OVERHEATING PROBLEMS

Six-cylinder engines have a plastic water pump which can struggle to cope as it gets older, so look for evidence of the engine getting hot or having previously overheated. On a four-cylinder engine, check for a faulty lambda sensor; see if the engine management light illuminates or check if it will pass the MoT emissions test; it’s a £180 fix. Other potential issues include a rattling timing chain (which costs £500650 to fix) or a failed thermostat. The latter often fails in the open position, so if the engine takes an age to get up to temperature, assume that a new thermostat is needed; a specialist will charge somewhere in the region of £75-100 to fit it.

CRASH TEST

Despite the Z3’s affordability and BMW roundel on the nose, these cars haven’t tended to appeal to hooligan drivers; most are cherished. But you still need to check for evidence of crash damage, such as rippled inner wings up front or a boot floor that’s not quite straight.

RAISE THE ROOF

Problems with the folding cloth roof are rare, but check it for wear and ensure that it goes up and down smoothly. Watch out for damaged or perished seals around the side windows or along the header rail; if these leak the interior will always be damp. The plastic rear window can go opaque – there was never a glass window option – but it’s usually possible to revive what’s there. Replacing a hood costs around £400. The optional plastic hard-top offered from 1998 makes the Z3 more usable in winter, but is much more of a faff to fit and remove than the weatherproof cloth roof.

ENGINE ISSUES

The Z3 came with eight-valve fourcylinder (1.8), 16-valve four-cylinder (1.9) and 24-valve six-cylinder (2.0, 2.2, 2.5, 3.0, 3.2) fuel-injected engines. All will easily take 200,000 miles in their stride, if properly maintained. The four-pot units tend to be more reliable, although failed cylinder head gaskets aren’t that unusual. European Z3s got an all-alloy straight-six, while US editions got a cast-iron block. UK powerplants featured Nikasil-coated liners which could be damaged by high-sulphur petrol, but any affected engines will almost certainly have been fixed under warranty; from September 1998 steel liners were fitted instead, eradicating the problem at a stroke.