The budget entry point to BMW's first-generation Z4. The 2.0i arrived in 2005 as a cheaper alternative to the inline-six variants, using the N46B20 four-cylinder with 150 hp and a 6-speed manual gearbox. It shares the E85 platform's sharp styling and rear-wheel-drive handling but substitutes the characterful six-cylinder soundtrack for a more modest four-pot. Production ran until 2008, and the electric soft-top mechanism is shared with the rest of the E85 range.· more· less
Low insurance and fuel costsEngaging rear-drive chassis
N46 engine less reliable than sixesElectric roof motor water ingress
Buy if: You want an affordable rear-drive roadster and can find one with documented service history, no cold-start rattle, and a functioning roof.
Avoid if: You want the straight-six character that defines the Z4 experience, or the car shows signs of timing chain noise or steering column issues.
Price & maintenance
Used price
€9,000
median asking price, typically 130,000 km
Typical range€8,000 – €11,000
Kilometres drivenAll
Maintenance cost
€750 – €1,450/year
at 15,000 km/year
Fixed costsservice, tyres, brakes€400 – €700 /yr
Risk bufferunplanned repairs€350 – €750 /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.
Plastic guide rails become brittle and chain tensioner loses pressure, causing cold-start rattle · more· less
The N46B20 inherits timing chain issues from the N42/N46 engine family. The plastic guide rails degrade with heat cycles, becoming brittle and cracking. Broken guide fragments can block the oil pump or contaminate the oil system. The chain tensioner bleeds oil pressure overnight, producing a distinctive rattle for several seconds on cold start. City driving with frequent stop-start cycles accelerates wear. Problems typically appear between 80,000 and 120,000 km. If the chain jumps timing, valve-to-piston contact can destroy the engine. BMW updated the tensioner part number during production. Replacement involves the chain, both guide rails, tensioner, and sprockets. Independent specialists charge around 1,200 to 1,800, while BMW dealers can reach 2,500.
Cracked exhaust manifold with integrated catalyst
€600 - 1,8002 of 9
The integrated catalytic converter adds weight and heat stress, causing manifold cracks · more· less
The 2.0i has an exhaust manifold with the catalytic converter integrated into a single unit. The extra weight and thermal cycling cause cracks, typically visible as an exhaust leak or ticking noise that gets louder over time. This is widely reported as a 2.0i-specific problem that the six-cylinder models largely avoid. A welding repair at an exhaust specialist costs around 200 to 400, but the manifold may crack again. Full replacement with the integrated catalyst runs 1,200 to 1,800 at independent shops. Many forum owners report having the manifold welded more than once before eventually replacing the entire unit.
Electric power steering column failure
€800 - 2,8003 of 9
EPS motor or control unit fails, causing sudden heavy steering and warning light · more· less
The E85 uses an electro-mechanical power steering system rather than conventional hydraulic assistance. The steering column motor or its control electronics can fail, causing a sudden increase in steering effort along with a warning light on the dash. This is a well-documented safety concern across the entire E85/E86 production run (2003-2009). BMW has not issued a general recall for this issue despite two decades of reports, though a limited UK recall covering 699 cars was issued. Specialist repair services can rebuild the column for 400 to 700, significantly less than a BMW dealer replacement at 1,800 to 2,800. A refurbished unit with a specialist warranty is the most cost-effective solution.
Convertible roof motor water damage
€800 - 1,5004 of 9
Blocked drain channels allow water to flood the roof motor housing, destroying the motor · more· less
The electric roof motor sits in a plastic container behind the cabin that is prone to water ingress. The rear roof drains block with dirt and debris over time, and when they cannot drain water fast enough, the motor housing fills up. Water corrodes the motor internals, eventually leading to complete failure. Symptoms include the roof operating slowly, stopping mid-cycle, or refusing to move at all. Motor replacement at a BMW dealer costs around 1,500 including labor. Specialist Z4 shops offer refurbished motors with relocation to the boot for 800 to 1,000, which also prevents future water damage. Preventive drain cleaning every six months is strongly recommended by the owner community.
VANOS and Valvetronic system issues
€300 - 1,5005 of 9
Variable valve timing solenoids and Valvetronic eccentric shaft sensor degrade with age and oil contamination · more· less
The N46 uses both VANOS (variable valve timing) and Valvetronic (variable valve lift). VANOS solenoid failure causes rough idle, loss of low-end torque, and camshaft position fault codes. Solenoid replacement is relatively affordable at 150 to 400. The Valvetronic eccentric shaft sensor is more labor-intensive: oil leaking past the sensor seal corrupts the signal, and replacement requires valve cover removal and special BMW tooling. The sensor and associated gaskets run 300 to 500 in parts, with 3 hours of labor. A complete VANOS unit rebuild, if needed, can reach 1,000 to 1,500.
Rear coil spring breakage
€250 - 5006 of 9
Springs fracture at the pigtail due to moisture and corrosion in the spring perch · more· less
Rear spring breakage is described by the Z4 community as a 'rite of passage' for E85 ownership. The springs break at the last two lower turns where dirt and moisture collect in the spring perch, causing rust and fatigue fracture. Detection is difficult without raising the car, as the broken spring may still sit in place and the car can appear to handle normally. M-Sport suspension and run-flat tires accelerate the issue. BMW issued a service bulletin (33 07 08, December 2008) addressing spring replacement procedures. A pair of replacement springs with fitting costs 250 to 500 at an independent garage.
Oil leaks (valve cover and oil filter housing gaskets)
€300 - 8007 of 9
Rubber gaskets harden and shrink with age, causing oil seepage from multiple points · more· less
Oil leaks are common on every N46 engine, not just the Z4. The valve cover gasket and oil filter housing gasket both use rubber seals that degrade with heat cycling over the years. Valve cover gasket replacement typically costs 350 to 500 including labor. Oil filter housing gasket runs 200 to 400. Since both gaskets tend to fail around the same age, many specialists recommend doing both at once to save on labor overlap. Visible oil residue down the left side of the engine usually indicates the oil filter housing gasket.
Brake line corrosion
€400 - 9008 of 9
Steel brake lines corrode regardless of mileage, creating a serious safety hazard · more· less
The E85's steel brake lines are prone to rust, particularly the rear lines. This is not age or mileage dependent and has been reported on cars with as few as 36,000 miles. In salty climates, nearly all E85 Z4s will need brake line replacement at some point. The rear lines are the most troublesome because the fuel tank must be dropped to access them properly, adding significant labor. A full brake line replacement runs 400 to 900 at an independent garage. Stainless steel upgrade kits are available for 80 to 120 and are the recommended permanent solution.
Window regulator failure
€100 - 4009 of 9
Internal cables and plastic components wear out, causing windows to stick or fail · more· less
The E85 shares its window regulator design with the E46. The internal cables and plastic guide components degrade with use, causing the window to move unevenly, stop mid-travel, or fail to stay in position. Grinding or clicking noises from the door during window operation indicate imminent failure. A DIY repair kit is available for around 20, making this an affordable fix for hands-on owners. Professional replacement with a new part runs 200 to 400 depending on whether dealer or independent labor is used.
More demanding than six-cylinder E85 variants
The N46 four-cylinder is widely considered the least desirable E85 engine option, with timing chain, VANOS, Valvetronic, and exhaust manifold issues that the inline-six variants largely avoid. The shared E85 platform problems (roof motor, rear springs, steering column, brake line corrosion) apply equally. With meticulous maintenance and regular roof drain cleaning, reliable ownership is possible, but the 2.0i demands more vigilance than the 2.5i or 3.0i alternatives.
Service history
Complete BMW dealer or specialist records essential. Verify oil changes every 12 months or 15,000 km. Condition-based servicing (CBS) often stretched intervals too far on N46 engines.
Cold start test
Start the engine completely cold. Listen carefully for any rattling in the first 30 seconds. This is the most important single check for a Z4 2.0i.
Test drive (minimum 30 minutes)
Include varied speeds and sharp turns. Feel for steering heaviness or warning lights. Operate the roof at least twice during the drive.
Tires and alignment
Check tread depth, tire age (date codes), and uneven wear. Rear tires wear faster on rear-drive roadsters.
Specific for this vehicle
Listen for cold-start timing chain rattle
A rattle lasting more than 2-3 seconds on cold start indicates timing chain tensioner wear. This is the single most important check. Walk away if rattle persists beyond 5 seconds.
Check for exhaust manifold cracks
Listen for ticking or blowing sounds from the engine bay. A cracked manifold will be louder when cold and may improve slightly when hot. Look for soot staining around the manifold-to-head joint.
Test power steering through full lock both directions
Any sudden heaviness, grinding, or a steering warning light indicates EPS column failure. This is a safety-critical check.
+ 5 more checksShow less
Operate the roof fully open and closed twice
The roof should complete its cycle in about 10 seconds without hesitation, strange noises, or stopping mid-travel. Slow operation suggests motor wear.
Inspect rear springs with the car raised
Look for fractures at the pigtail end of the rear coil springs. Broken springs are difficult to detect from the outside but are very common on E85s.
Inspect brake lines from underneath
Look for any rust or corrosion on the steel brake lines, especially the rears. Surface rust is expected, but flaking or pitting means replacement is needed.
Check for oil leaks around valve cover and filter housing
Look for oil residue on the left side of the engine block (oil filter housing) and around the valve cover perimeter. Some seepage is expected at this age, but dripping indicates gasket replacement is due.
Test roof drains by pouring water
With the roof open, pour a small amount of water into the rear drain channels. Water should exit freely at the underside of the car. Slow or no flow means blocked drains and imminent roof motor risk.
EPS steering column limited recall (699 UK cars, selected VINs)Verify if applicable
Contact BMW with the VIN to verify all recall status. The PCV valve heater recall is particularly critical as it can cause engine bay fires even when parked. The Takata airbag recall affects many 2003-2008 BMW models. The steering column issue was only covered by a limited recall in the UK affecting specific VINs.
Warranty Status
Factory warranty (2 years)Expired on all Z4 2.0i models
Rust perforation warranty (12 years)Expired on all Z4 2.0i models
Extended warrantyNot typically available at this age
All E85 Z4 2.0i models are well outside any factory or extended warranty. Budget accordingly for all repairs.
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.
