BMW xDrive30i
The 258 hp top version of the N52 is one of the last large high-revving naturally aspirated engines from BMW: a magnesium-aluminium composite block that defines the class through extreme smoothness and a willingness to rev that drivers describe as 'like a sewing machine' — so even and effortless in its climb. Compared to the N54 turbo it sounds cleaner and more natural, without turbo hiss; instead a clear naturally aspirated note that fills out with increasing revs. Cold-start behaviour is impeccable; in daily use it runs nearly maintenance-free. Typical weaknesses: electric water pump (fails without warning, 80,000–150,000 km, preventive replacement recommended), Valvetronic eccentric shaft sensor (fault code, limp mode), VANOS solenoids with sludge build-up. Buying tip: check service history, as missed oil changes can permanently impair VANOS function.
NA Straight-Six Bliss
Last great BMW NA straight-six — deep rumble at idle, magnificent above 5,000 rpm.
Engine Weaknesses 5
The N52 electric water pump is a known wear item. When it fails the engine overheats quickly. Recommended: preventive replacement when any abnormalities appear or from around 100,000 km.
Symptoms: Coolant temperature gauge rises quickly, coolant loss, audible pump malfunction, engine overheating.
The gasket between the oil filter housing and the engine block ages and becomes porous, allowing oil into the coolant. Symptoms resemble a head gasket failure. Early replacement of both seals is recommended.
Symptoms: Oil film on the coolant; discoloured oil filler cap; coolant slightly foamy or brownish; no white exhaust smoke — a key differentiator from head gasket damage
The Valvetronic eccentric shaft sensor fails due to moisture and ageing. Fault code 2A31 is typical. The sensor costs approximately €275; installation requires opening the cam cover.
Symptoms: Rough idle; severe judder with light throttle input; increased fuel consumption (up to +30%); fault code 2A31; engine runs better with the sensor disconnected
The N52 magnesium cam cover has known sealing problems. Oil loss at the cam cover gasket, eccentric shaft sensor, and camshaft adjustment motor are common. Aluminium bolts must not be reused.
Symptoms: Oil loss at the cylinder head, oil smell, visible oil traces at the top of the engine, oil spots on the exhaust manifold.
The N52 VANOS solenoid valves block with oil sludge, particularly with long oil change intervals or short-trip driving. Cleaning is possible; a valve swap often suffices. Improved software from 2007/08.
Symptoms: Rough running; poor throttle response; rpm fluctuations at idle; warning light; camshaft phasing fault code; cold-start misfires
Vehicle Weaknesses 8
Air suspension compressor and air springs fail frequently from 80,000 km. Average lifespan of air springs is 100,000–120,000 km. Aftermarket springs (Arnott/Continental) cost around €115 each — BMW pricing is significantly higher.
On cars with a panoramic roof, blocked drainage channels can allow water into the boot, where sensitive control units sit beneath the load floor trim. Consequential costs are considerable.
The xDrive transfer case ATC700 wears prematurely with mismatched tyre rolling circumferences or neglected oil changes. Juddering on pull-away is the typical early symptom. Replacement can cost up to €5,000.
From around 150,000 km the rear air springs become porous; the compressor runs continuously and overheats. Both sides should be replaced simultaneously as the second bellows typically follows shortly after.
Electronically controlled Adaptive Drive dampers fail from 120,000 km; replacement is only possible with BMW parts and costs around €800 per damper. Standard suspension is far more trouble-free.
A creaking, sometimes leaking panoramic roof is a well-known TÜV defect on the E70. Recommendation: choose a car without a panoramic roof. A new roof centre unit costs around €330 without fitting.
iDrive system shows frequent faults after 100,000 km. The ignition switch can prevent the car from starting. The electric water pump on the N55 is prone to wear.
Up to model year 2010, BMW used cheaper sealing compound rather than proper gaskets for the tail lights, causing moisture ingress and short circuits in the rear lights.