BMW Z4 E85/E86 N43/N46 problems
The BMW Z4 E85/E86 used the N43/N46 from 2005 to 2008 (2.0i). 3 documented faults affect it; the most important is “wear and breakage of the timing chain guides” (critical severity, common). Our verdict: “With caution”. Among the documented engines of the BMW Z4 E85/E86, the safest option is the N52 / N53.
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Engine score on this car
4.1 out of 10Low reliability
Only counting the faults that affect the versions and years of the Z4 E85/E86. How we calculate it
Overall score for the BMW Z4 E85/E86
6.4 out of 10Acceptable reliability
Engines, gearbox, suspension, brakes, electronics and the rest of the car. See breakdown
BMW N43 and N46 (N43B16 / N43B20 / N46B20 / N46NB20) · Petrol
- In the Z4 E85/E86
- 2005–2008[1]
- Name
- 2.0i
- Faults that affect it
- 3 · 1 of high or critical severity
Verdict for the version it uses
N46B20 127-148 hp, indirect injection (2004-2007)2004–2007 · 127–148 hp · N46B20A, N46B20O1, N46B20U0, N46B20U1, N46B20U2
With cautionLike the rest of the family, it can suffer wear of the timing chain guides and tensioner and of the Valvetronic or VANOS; as it has no direct injection, it is not affected by the injector and NOx sensor failures documented on the N43.[2][3]
Faults that affect the Z4 E85/E86
Only those that affect the versions and years that this car used. The BMW N43/N46 has 4 documented faults in total.
- Critical severityFrequency: CommonTimingWear and breakage of the timing chain guidesYes: both the N43 and the N46 can stretch the timing chain and wear its plastic guides and tensioner. On the N43, English-language Wikipedia documents that a broken guide can release fragments that block the oil strainer and cause serious damage through lack of lubrication.
- Medium severityFrequency: CommonIntakeWear of the Valvetronic and the VANOS solenoid valvesOver the years, the eccentric shaft or the actuator motor of the Valvetronic can wear and cause heavy idle fluctuations; the VANOS solenoid valves also fail over time, with similar symptoms and a loss of power. According to English-language Wikipedia, the 1.6-litre N43B16 does not have Valvetronic.
- Medium severityFrequency: CommonLubricationOil leaks and consumption (rocker cover, vacuum pump and valve stem seals)Over the years, the rocker cover gasket and the brake servo vacuum pump gasket start to seep oil on the N43 and N46; on the N46 there are also the valve stem seals, which can cause more noticeable oil consumption than on the N43.
What to check before buying a used BMW Z4 E85/E86 N43/N46
Each point comes from a documented fault that affects this car. You can tick them off as you inspect it.
If it has the BMW N43/N46 (2005–2008)
Wear and breakage of the timing chain guides
Critical severityWear of the Valvetronic and the VANOS solenoid valves
Medium severityOther engines and gearboxes of the BMW Z4 E85/E86
Score for each one with the faults that affect this car, from best to worst.
Faults of the BMW Z4 E85/E86 outside the engine
Suspension, brakes, electronics and the rest of the car: they occur with any engine.
- Medium severityFrequency: OccasionalBodywork and interiorElectric hood motor and mechanism failureAccording to the reports collected by fiches-auto.fr, the electric hood on the Z4 E85 is the most frequently cited fault outside the engine: 13 of 78 reports mention a failed motor, jamming or water drainage problems, between 100,000 and 220,000 km.
- Medium severityFrequency: OccasionalGearbox and clutchPremature clutch wear and slipping when hotAccording to the reports collected by fiches-auto.fr, 5 of 78 Z4 E85 owners cite clutch faults, with slipping when hot or problems engaging gear, from around 150,000 km. No cost is given.
- Medium severityFrequency: OccasionalGearbox and clutchNoises and difficulty engaging gears in the manual gearboxAccording to the reports collected by fiches-auto.fr, 7 of 78 Z4 E85 owners cite noises or difficulty engaging gears in the manual gearbox and 2 more cite differential faults, between 65,000 and 258,000 km.
Buying a BMW Z4 E85/E86 N43/N46?
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Frequently asked questions
Is the BMW Z4 E85/E86 N43/N46 reliable?
The BMW Z4 E85/E86 used the N43/N46 from 2005 to 2008 (2.0i). 3 documented faults affect it; the most important is “wear and breakage of the timing chain guides” (critical severity, common). Our verdict: “With caution”. Among the documented engines of the BMW Z4 E85/E86, the safest option is the N52 / N53.
What faults does the BMW Z4 E85/E86 N43/N46 have?
The documented ones that affect this car are: wear and breakage of the timing chain guides (critical severity), wear of the Valvetronic and the VANOS solenoid valves (medium severity) and oil leaks and consumption (rocker cover, vacuum pump and valve stem seals) (medium severity).
Which engine should you choose for the BMW Z4 E85/E86?
None has a «Buy» verdict; the safest option is the BMW N52 / N53, with a «With caution» verdict.
Own a BMW Z4 E85/E86 N43/N46? Tell us what faults you have had and at how many kilometres. Report your fault.
Sources
Every fact on this page links to its source. If you find an error, let us know.
- BMW Z4 (E85)Wikipedia (inglés) · Other source · consulted 27 September 2026
- BMW N43: Bei diesem Benziner ist Ärger vorprogrammiertGebrauchtwagenberater · Motoring press · consulted 27 September 2026 · in German
- BMW N46: Typische Probleme & HaltbarkeitGebrauchtwagenberater · Motoring press · consulted 27 September 2026 · in German
- BMW X1 E84 – Bekannte Probleme & SchwachstellenGebrauchtwagenberater · Motoring press · published 9 May 2023 · consulted 27 September 2026 · in German