The entry-level E89 Z4 pairs a turbocharged 2.0-litre N20 four-cylinder with a retractable hardtop roadster body. Introduced in 2011 to replace the six-cylinder sDrive23i, the sDrive20i delivers 184 PS through either a 6-speed manual or 8-speed automatic. The 18i, 20i and 28i are not simply the same engine with different software: BMW lists separate N20B20U0 and N20B20O0 codes, compression ratios of 10.0 and 10.3 for the 20i and 28i, and modified injection and turbocharging. Production ran through 2016, and the retractable hardtop gives it year-round usability that a soft-top roadster lacks.· more· less
Retractable hardtop, all-season usableLower running costs than 6-cylinder Z4s
N20 timing chain guide issues (engines built before mid-2015)Hardtop hydraulics can fail expensively
Buy if: You want an affordable rear-drive roadster with a hardtop and can verify the timing chain service status on pre-2015 models.
Avoid if: You want the straight-six sound and torque that defined earlier Z4s, or the car has no service records covering timing chain and cooling system work.
Price & maintenance
Used price
€19,500
median asking price, typically 90,000 km
Typical range€15,800 – €21,400
Kilometres drivenAll
Maintenance cost
€900 – €1,650/year
at 15,000 km/year
Fixed costsservice, tyres, brakes€500 – €850 /yr
Risk bufferunplanned repairs€400 – €800 /yr
Price estimates are based on German asking prices. Prices and costs vary by vehicle condition and location.
Ownership costs
Maintenance assumes 15,000 km a year. Price estimates are based on German asking prices. Prices and costs vary by vehicle condition and location.
Used price
€19,500
Typically €15,800 – €21,400, at around 90,000 km.
Kilometres driven
Maintenance
€900 – €1,650per year
€500 – €850
service, tyres, brakes
€400 – €800
repair buffer
Price & maintenance
Used price
€19,400
median asking price, typically 110,000 km
Typical range€17,000 – €24,500
Maintenance cost
€900 – €1,650/year
at 15,000 km/year
Fixed costsservice, tyres, brakes€500 – €850 /yr
Risk bufferunplanned repairs€400 – €800 /yr
Price estimates are based on French asking prices. Prices and costs vary by vehicle condition and location.
Ownership costs
Maintenance assumes 15,000 km a year. Price estimates are based on French asking prices. Prices and costs vary by vehicle condition and location.
Used price
€19,400
Typically €17,000 – €24,500, at around 110,000 km.
Plastic timing chain guides crack and fragment, primarily on engines built before mid-2015 · more· less
The N20 engine uses plastic timing chain guides that are prone to premature degradation, particularly on engines produced between 2011 and mid-2015. The guides become brittle over time, introducing slack to the timing chain. Early symptoms include a high-pitched whining or whirring noise from the front of the engine, most noticeable between 1,500 and 2,500 RPM. This typically develops between 60,000 and 120,000 km. If ignored, the chain can skip teeth or break entirely, causing catastrophic piston-to-valve contact that destroys the engine. The 7 year and 70,000 mile programme often quoted here was a BMW North America warranty extension whose E89 entry is the sDrive28i, so it does not establish European cover for this car. Late-production N20 engines (mid-2015 onwards) received redesigned guides made from a more durable material. A full timing chain replacement (chain, guides, tensioner, sprockets) costs approximately €1,500-2,500 at an independent specialist, or up to €3,500 at a BMW dealer. The job requires 8-12 hours of labor.
Oil filter housing gasket and valve cover gasket leaks
up to €1,2002 of 7
Gaskets degrade from heat cycling, causing oil leaks onto engine and exhaust components · more· less
The N20 is well known for oil leaks from the oil filter housing gasket (OFHG) and valve cover gasket. The OFHG typically fails first, usually between 60,000 and 100,000 km, because it sits in a high-heat area. Symptoms include oil smell, visible oil on the engine block, and oil dripping onto the exhaust manifold (creating a burning smell or smoke). The valve cover gasket tends to follow shortly after. While the gasket parts themselves are inexpensive (€15-40 each), labor adds up. An OFHG replacement at an independent shop runs about €200-400, while a combined OFHG and valve cover gasket job costs €400-700. At a BMW dealer, expect €700-1,200. Most N20 engines over 80,000 km will develop at least one oil leak.
Electric water pump and thermostat failure
up to €1,0003 of 7
Electric water pump fails without warning, typically between 80,000 and 130,000 km · more· less
Like other modern BMW engines, the N20 uses an electric water pump that can fail suddenly and without warning. When it fails, the engine overheats rapidly. The Z4's compact engine bay makes replacement somewhat more involved than in a 3 Series. The pump itself costs approximately €250-400 for OEM quality, and the thermostat housing should be replaced simultaneously (adding €80-150 in parts). Labor runs 3-5 hours. Total cost at an independent shop is typically €500-700, while a BMW dealer charges €700-1,000. Many specialists recommend proactive replacement around 100,000 km to avoid a roadside breakdown. Continuing to drive with a failed pump, even briefly, risks head gasket damage from overheating.
Retractable hardtop hydraulic pump failure
up to €2,5004 of 7
Hydraulic pump seals degrade from water intrusion or age, preventing roof operation · more· less
The E89's retractable hardtop relies on a complex hydraulic system with a pump, multiple cylinders, and microswitches. Common failure causes include water intrusion into the pump unit, stuck relays that overheat the motor, and degraded internal seals. When the pump fails, the roof may stop mid-cycle or refuse to operate entirely. A BMW dealer quotes approximately €1,500-2,500 for pump replacement (the job requires 8-10 hours of labor for pump access). Specialist rebuild services are available for approximately €600-900, replacing all internal seals and solenoids. Roof lifter struts on each side can also fail independently, adding €200-400 per side. Operating the roof regularly, even in winter, helps prevent seal seizure.
Water ingress into boot and rear light clusters
up to €5005 of 7
Factory sealant around boot lid and rear lights degrades after approximately 5 years · more· less
This is one of the most commonly reported E89-specific issues, affecting all engine variants. The factory sealant strip around the boot lid and rear light cluster seals degrades over time, allowing water into the boot area and light assemblies. Symptoms include condensation inside rear lights, corrosion in the light assemblies, and water pooling in the boot well. On cars with the roof-down stowed hardtop, water can reach the hydraulic pump, accelerating its failure. BMW updated the rear light seals from 2013 onwards, but earlier cars are particularly susceptible. Resealing costs approximately €150-300 at a specialist. Replacement of corroded light clusters adds €100-250 per unit. A green trim clip in the boot area is sometimes quoted as proof that the work was done, but it comes from North American service information rather than a European campaign, so ask for the invoice instead.
VANOS solenoid malfunction
up to €5006 of 7
Oil-contaminated VANOS solenoids cause rough idle, fault codes in the 2D54 to 2D61 group, and reduced performance · more· less
The N20 uses two VANOS solenoids controlling variable valve timing on intake and exhaust camshafts. When these become clogged with oil sludge or debris, symptoms include rough idle that settles after driving, a rattling or ticking noise on startup, and reduced power. BMW technical guidance for the E89 N20 lists fault codes 2D54, 2D55, 2D56, 2D57, 2D60, 2D5A, 2D5B and 2D61 for this area. The solenoids themselves cost about €60-100 each, with straightforward replacement (1-2 hours labor). The underlying cause is often extended oil change intervals or use of incorrect oil viscosity. Cleaning or replacing both solenoids simultaneously costs approximately €200-500 depending on labor rates. This is preventable with strict adherence to oil change intervals.
Alloy wheel cracking (19-inch wheels)
up to €1,2007 of 7
Style 296 and 326M 19-inch wheels develop hairline cracks on the inner rim · more· less
E89 Z4 models fitted with optional 19-inch alloy wheels (particularly Style 296) are prone to developing hairline cracks on the inner rim lip. The combination of run-flat tires with very short sidewalls, negative rear camber, and aggressive wheel design concentrates road forces on the inner rim edge. BMW redesigned the 296 wheel around 2012, and a US class action settlement covered 2009-2013 models. In Europe, there was no equivalent program. Cracks cause slow air pressure loss and can lead to sudden tire deflation. Each cracked wheel requires replacement (approximately €300-500 per wheel for OEM, less for aftermarket). Cars on 17-inch or 18-inch wheels are rarely affected. Inspect inside rim edges carefully during any pre-purchase inspection.
Simpler than the six-cylinder Z4s, but the N20 has its own well-documented weak points
The Z4 sDrive20i avoids the twin-turbo complexity of the 35i variant, making it the lowest-risk E89 engine choice. However, the N20 brings its own concerns: timing chain guide degradation on engines built before mid-2015 is the most serious, potentially causing catastrophic engine damage if neglected. Oil leaks, water pump failure, and VANOS issues are common across the N20 range. The E89-specific hardtop hydraulics and boot water ingress apply regardless of engine. Late-production cars (2015-2016) with updated timing chain components and service evidence of proactive maintenance are the safest purchases.
Service history
Complete BMW dealer or specialist records essential. Verify oil change intervals (maximum 15,000 km or 12 months). The N20 is sensitive to oil quality and change frequency.
Cold start
Start the engine completely cold. Listen for unusual whining from the front of the engine (timing chain) and any rough idle or rattling (VANOS solenoids).
Test drive
Minimum 30 minutes including varied speeds. Watch for warning lights, boost issues, and any hesitation under acceleration.
Underside inspection
Check for oil leaks around oil filter housing, valve cover, and oil pan area. Some oil residue is common on higher-mileage N20 engines.
Specific for this vehicle
Listen for timing chain whine at 1,500-2,500 RPM
A high-pitched whining or whirring noise from the front of the engine is the earliest warning sign of guide degradation. This is especially important on cars built before mid-2015. If present, budget for timing chain service before purchase.
Operate the retractable hardtop fully at least twice
Open and close the roof twice during inspection. Listen for unusual sounds, watch for hesitation or stopping mid-cycle. A roof that pauses or operates slowly indicates hydraulic pump weakness.
Inspect boot area for water ingress
Lift the boot carpet and check for dampness, water staining, or corrosion. Check rear light clusters for condensation or misting. The green trim clip sometimes quoted as proof of the repair comes from North American service information rather than a European campaign, so ask for the invoice instead.
+ 3 more checksShow less
Check for oil leaks on engine block
Visually inspect around the oil filter housing (driver side of engine) and valve cover perimeter. Burning oil smell from exhaust side suggests OFHG leak dripping onto hot components.
Verify timing chain service status (cars built before mid-2015)
Ask whether the timing chain, guides, and tensioner have been replaced. If the car was built before mid-2015, has over 80,000 km and no chain service on record, treat this as a likely upcoming expense.
Check alloy wheels for cracks (19-inch only)
If fitted with 19-inch wheels, especially Style 296, run a finger along the inner rim edges of all four wheels. Hairline cracks cause slow pressure loss and are common on these wheels.
Recalls and Technical Service Bulletins
Possible failure of electric power steering assistance (UK recall R/2012/081, BMW campaign 0032090200; Z4s built 1 November to 31 December 2011, which overlaps early sDrive20i production; UK scope, check build date and VIN)Verify completed
Contact BMW with the VIN to verify all recalls and service actions have been completed. Several items commonly listed for this car do not belong to it: the N20 timing chain programme is a BMW North America warranty extension covering the sDrive28i, the VANOS bolt action covers N51, N52 and N55 engines, and BMW's Takata lists for the UK, Ireland and France do not include the E89 Z4.
Warranty Status
Factory warranty (2 years)Expired on all E89 Z4 models
N20 timing chain programme (BMW North America, sDrive28i)Not applicable to the European sDrive20i
Rust perforation warranty (12 years)May still apply for 2014-2016 models
All E89 Z4 sDrive20i models are outside their original 2-year factory warranty. The N20 timing chain programme offered in the US was a warranty extension whose E89 entry is the sDrive28i, so it is not European cover for this car. Budget for all maintenance and repairs without warranty support, apart from any rust perforation cover that is still running.
Sources: Research draws on model-specific owner forums and owner communities, recall information from official authorities, German automotive press, and multiple workshop cost references cross-checked against each other.
This report is for informational purposes only and does not constitute professional advice. Estimates may be inaccurate. Always have a qualified specialist inspect the vehicle before purchase. We accept no liability for decisions made based on this information.
