Pure driving thrills from Bavaria's finest roadster
The Z4 spans three generations and a huge price range in the UK, from sub-£5,000 E85s to £40,000+ G29 models. The E85 (2003-2009) with naturally aspirated straight-sixes is gaining classic status, while the E89 (2009-2016) folding hard-top offers year-round usability from around £10,000. The G29 (2019+) shares its platform with the Toyota Supra, and prices start from about £28,000 used. Road tax can sting: pre-March 2006 cars are £325/year, post-March 2006 models jump to £570/year.
We track 10 known issues across the BMW Z4 range, including 1 rated as safety-critical. Knowing which variants and configurations to approach with caution can save you from expensive surprises after purchase.
Found a BMW Z4? Enter the reg to see which of our 10 known issues apply to that exact car, plus full MOT history and mileage checks.
E85 (2003–2008) — Engine options included the 2.2i, 2.5i, 3.0i, Z4 M. Our database flags 3 known issues on this generation, 1 of which are rated as safety-critical. The most significant concern is Flexible brake hose deterioration (£150–£400 to address).
E89 (2009–2016) — Engine options included the sDrive20i, sDrive20i (later), sDrive25i, sDrive30i. Our database flags 7 known issues on this generation, 1 of which are rated as safety-critical. The most significant concern is Flexible brake hose deterioration (£150–£400 to address).
G29 (2018–2024) — Engine options included the sDrive20i, sDrive30i. Our database flags 4 known issues on this generation, 1 of which are rated as safety-critical. The most significant concern is Flexible brake hose deterioration (£150–£400 to address).
MOT data shows Z4 models fail brake hose inspections at 31.7 times the national average across all generations. Flexible brake hoses develop cracks, bulging, or internal deterioration with age. This is a serious safety issue as hose failure causes complete brake system failure. The failure rate is worsening year on year.
Brake hose failure causes complete loss of braking to that wheel or circuit, creating serious accident risk. The car should not be driven if hose deterioration is suspected. This is a safety-critical failure requiring immediate repair. Replacement costs £80-200 per hose.
Check brake disc condition for lipping or scoring. Test braking at moderate speed for pulling to one side or vibration through the steering wheel. Review MOT advisories for brake-related items.
The VANOS variable valve timing system on M54 engines uses oil pressure to actuate camshaft timing. Seals within the VANOS unit deteriorate causing rough idle, poor cold starting, and reduced power output. Oil leaks from the valve cover gasket and oil filter housing gasket are near-universal on these engines due to heat cycling and age. The S54 in the Z4 M has documented rod bearing wear issues that require preventive replacement.
VANOS failure causes poor running and reduced performance but rarely leaves you stranded. Oil leaks from valve cover and filter housing are progressive and will eventually cause MOT emission failures. S54 rod bearing failure causes complete engine destruction. Repair costs £200-800 for VANOS seals, £400-600 for gasket replacements.
Listen carefully for a rattle or ticking noise from the engine on cold start — this is the most common early sign. Ask for evidence of chain replacement in the service history. On higher-mileage cars without documented replacement, budget for preventative work.
The soft-top mechanism on E85 Z4s uses an electric motor and cable system that fails due to water ingress through deteriorated seals. The steering system develops notchy, sticky feel particularly in cold weather due to worn components in the steering column or rack. Rear coil springs are prone to fracture near the lower mount.
Failed roof motor leaves the roof inoperable in its current position. Sticky steering affects handling and driver confidence. Broken rear springs can damage tyres and affect handling stability. Roof motor replacement costs £500-1200, steering issues £200-600, spring replacement £150-300 per side.
Check panel gaps are even and consistent all the way around the car. Look for signs of repainting — overspray on rubber seals, mismatched paint texture or colour differences between panels. Open and close all doors, the boot and bonnet to check alignment.
The N52 engine uses an electric water pump that fails without warning signs, causing sudden overheating and potential engine damage. The thermostat housing is plastic and cracks with age, causing coolant loss. These are the primary failure points on an otherwise reliable engine.
Electric water pump failure causes rapid overheating that can warp the cylinder head or damage pistons within minutes. Thermostat housing failure causes gradual coolant loss. The car should not be driven if overheating occurs. Repair costs £300-700 for pump and housing replacement.
Check the coolant level and look for any white residue or staining around hoses, the expansion tank and radiator. After a test drive, check the temperature gauge stayed stable and look underneath for drips. Ask whether key cooling components have been replaced.
The N54 twin-turbo engine suffers from well-documented high pressure fuel pump (HPFP) failures causing extended cranking and power loss. Later index pumps (07 and above) are more reliable. Wastegate rattle on acceleration is common due to worn actuator mechanisms. Fuel injectors develop seal leaks causing rough running.
HPFP failure can leave you stranded with a non-starting engine. Leaking injectors cause poor fuel economy and rough running. Wastegate rattle is mainly noise but indicates turbocharger wear. HPFP replacement costs £800-1500, injector overhaul £600-1200, wastegate replacement £400-800 per side.
Check for fuel smells around the engine bay and underneath the car. Look for staining or wetness around fuel lines and connections. Injector issues may cause rough running or misfires that are most noticeable at idle.
For the full breakdown of all 10 tracked issues with repair costs, see the BMW Z4 common problems page.
Based on 202k real DVSA MOT tests, the BMW Z4 fails more often than average on several items. The biggest outlier is light unit fault at 171x the fleet average, followed by parking brake inefficient (135x).
When viewing a specific car, check its MOT history for recurring advisories in these categories. See the full BMW Z4 MOT failure breakdown for data at every mileage point.
Routine servicing (oil and filter change every 10k miles) typically costs £80–£150 at an independent garage.
See the full BMW Z4 service schedule for every interval and cost breakdown.
The BMW Z4 has some well-documented weak points, including 1 safety-critical issue that demand careful checking. The right example, properly maintained, can still be a sound purchase — but cutting corners on the pre-purchase inspection is not advisable. E85 2003-2008 with the 3.0 (M54 engine) is the purist's choice: reliable, naturally aspirated, and now appreciating. For the E89, 2013-2016 facelift models have resolved early teething issues with the folding roof mechanism. The G29 from 2019 onwards with the B48 2.0-litre turbo (sDrive20i/30i) offers the best reliability; the M40i is thrilling but costlier to maintain. Avoid early 2009-2010 E89 cars with first-year roof mechanism issues.
Before committing, check the car's full MOT history, verify the service record is complete, and if possible arrange a specialist inspection. Enter any registration into our free report to see the complete picture.
Get Car Wise maintains a database of known mechanical issues for every popular car on UK roads, tracking the faults that owners, specialists and DVSA data reveal.
When you run a report on a specific BMW Z4, we cross-reference the exact variant, engine and age against our database of 10 known issues. Combined with full MOT history analysis, mileage verification and DVLA data, you get a complete picture before viewing.
Enter the registration for MOT history, mileage verification, known faults for that exact variant, and a Get Car Wise Score.
This guide was compiled from independent expert reviews, DVSA MOT data, specialist workshops and our own database of 10 known BMW Z4 issues. We are not affiliated with any source listed.