BMW 2.0i
Four-cylinder with variable valve lift (Valvetronic). Smooth and frugal; the Valvetronic eccentric shaft is the known weakness.
Roadster Looks, Economy Engine
150 hp keeps up with traffic, but the four-pot doesn't match the Z4's promise. Drop the roof and the mood lifts — the engine alone won't do that.
Engine Weaknesses 5
The timing chain stretches prematurely due to a faulty chain tensioner. Plastic guide rails become brittle and break. Engine damage from chain jump is possible.
Symptoms: Rattling or clattering on cold start in the first few seconds, which improves or worsens as the engine warms up.
The Valvetronic actuator motor or eccentric shaft fails at around 150,000 km. Fault code 2A67 is typical. The engine runs but without variable valve lift control — increased fuel consumption, limp mode.
Symptoms: Judder at 2,000 rpm; rough cold start; increased fuel consumption; engine stumbling when pulling away; fault code 2A67
The VANOS solenoid valves wear and cause rpm fluctuations, power loss, and starting difficulties, especially at low revs.
Symptoms: Rpm fluctuations at idle, power loss at low revs, occasional starting difficulties.
From around 190,000 km valve stem seals tend to harden, leading to blue smoke and increased oil consumption. The vacuum pump and cam cover gasket are further typical sources of oil loss.
Symptoms: Blue smoke on cold start or when accelerating, increased oil consumption (more than 0.5 L/1,000 km).
The N46 VANOS sealing rings wear from around 100,000 km. Oil pressure drop in the VANOS unit causes timing issues. Replacing the seal kit is cheaper than a complete unit swap.
Symptoms: Ticking or tapping noise after cold start (sounds like a diesel); power loss below 3,000 rpm; increased fuel consumption; rough idle
Vehicle Weaknesses 7
The hydraulic pump for the Z4 E85 hood is mounted in a poorly protected position. Blocked drains allow water ingress; the pump corrodes and fails. Replacement is labour-intensive and expensive.
The electric power steering on the Z4 E85 occasionally fails — particularly on short-trip drivers as the battery becomes too weak. Steering angle sensor faults and column defects also occur.
The N46B20 four-cylinder in the 2.0i Z4 E85 suffers from premature timing chain wear due to a weak chain tensioner. Neglected oil maintenance causes the chain to elongate and can lead to engine damage.
Water enters through leaking tail lights or the boot vent. The expansion rivets on the tail lights become porous, seals age and allow moisture in. Can lead to short circuits and mould.
Ignition coil failures are a known issue on the Z4 E85, particularly at higher mileage. Oil from the valve cover gasket into the spark plug tubes is often a contributing factor. Multiple coils can fail in succession.
The sporty suspension setup on the Z4 E85 leads to above-average tyre wear, especially at the rear. Rear tyres can be at the wear limit after just 25,000 km. Broken springs have also been reported.
On the E85 Z4, the rain sensor and window regulator motors fail more often than usual. The rain sensor triggers in sunshine; windows move jerkily or not at all — both are age-related symptoms.
Reports & Tests
1161 owner complaints filed with NHTSA (2002–2008). Most reported: Steering (965), Airbags (86), Electrical (52).