Buying Guide / 2003 - 2008
BMW Z4 E85/E86
The overlooked BMW sports car. Smooth inline-6 power in a proper roadster package, from the 150bhp 2.0i to the 343bhp Z4 M weapon.
The overlooked BMW sports car. Smooth inline-6 power in a proper roadster package, from the 150bhp 2.0i to the 343bhp Z4 M weapon.
The E85 Z4 is a proper roadster. The 3.0si (265bhp) is the sweet spot. The Z4 M (S54 engine, 343bhp) is the weapon. Chris Bangle's design was controversial at launch but has aged beautifully.
We've compiled 7 known issues for the Z4 E85 in our database. Here are the five that matter most, drawn from specialist knowledge and owner communities across the UK.
Go deeper: Run a free Carwise report on a specific Z4 to see which issues apply to that exact car, plus full MOT history, mileage checks and a personalised buyer checklist.
The electric roof on the E85 roadster is a complex mechanism with multiple potential failure points. Micro-switches that detect roof position can fail, hydraulic rams lose pressure over time, and the roof ECU itself can develop faults. Any of these can leave the roof stuck open or partially closed.
Repairs range from relatively cheap micro-switch replacement to expensive ECU or hydraulic ram renewal. A roof stuck in the open position in British weather is not ideal.
Operate the roof at least three times during a viewing. Listen for hesitation, grinding or slow operation. Check that it seals fully when closed. Look for water stains inside the cabin. Ask the seller about any previous roof repairs.
The rear subframe mounts can develop movement on harder-driven Z4s, particularly those that have been tracked or driven aggressively. Worn mounts cause vague rear-end handling, unusual tyre wear and clunking noises over bumps.
This is more common on the higher-powered 3.0 and Z4 M models. The additional torque and cornering forces accelerate bush wear. Polyurethane bushes are a popular upgrade.
Listen for clunks from the rear over speed bumps. Check for uneven rear tyre wear. Have the subframe mounts inspected on a ramp. Cars with track day history should be checked more thoroughly.
The same BMW cooling system weakness that affects the E36 and E46. Plastic expansion tanks, thermostat housings and water pump impellers become brittle with age and heat cycling. Failure is often sudden and without warning.
Overheating on these engines can cause head gasket failure and warped cylinder heads. A proactive cooling system refresh with aluminium parts is considered essential maintenance on any E85 Z4 over 10 years old.
Check coolant level and condition. Inspect the expansion tank for discolouration and cracks. Check the temperature gauge behaviour on a test drive. Ask if the cooling system has been refreshed with metal components.
The window regulators on the Z4 use a cable mechanism that can snap or jump off its track. Symptoms include slow window operation, grinding noises, or a window that drops into the door and will not come back up.
This is a common and relatively inexpensive fix, but a window stuck in the down position on a roadster is a security risk and an immediate problem in wet weather.
Operate both windows fully up and down during a viewing. Listen for grinding or hesitation. Check that both windows seal properly when fully raised.
The electronic steering lock can fail, preventing the car from starting entirely. The steering column locks and the ignition refuses to engage. This can happen intermittently at first before becoming a permanent failure.
The fix involves either replacing the ELV motor or having the unit repaired by a specialist. Some owners opt to have the ELV permanently disabled, though this has implications for insurance.
Start the car from cold and check that the steering lock disengages cleanly. If the seller mentions any starting issues or steering lock warnings, investigate further. Check for any warning lights on the dashboard related to the steering system.
The Z4 E85 is the overlooked BMW sports car. The 3.0si offers smooth, linear inline-6 power in a proper open-top roadster. The Z4 M with the S54 engine from the E46 M3 is a genuine weapon: raw, loud and intoxicating.
Prices are accessible because the Z4 lives in the shadow of the M3 and 1M, making it arguably the best-value BMW sports car you can buy. The E86 coupe variant is rarer and holds value better, but the roadster is the one that makes you reach for the roof button on every drive.
The electric roof is the biggest concern on the roadster. Budget for potential repairs and test it thoroughly before buying. Beyond that, the standard BMW cooling system refresh is essential maintenance. Get those two things right and you have a fantastic sports car for very little money.
Enter the registration for MOT history, mileage verification, known faults for that exact variant, and a Carwise Score.
Check a vehicle nowCompiled from independent expert sources, specialist workshops and our database of 7 known Z4 E85 issues. We are not affiliated with any source listed.
Hero image credit: BMW Z4 E85 press photo