BMW 525d
Legendary common-rail straight-six diesel. Extremely smooth and long-lived; turbocharger and EGR valve are the most common weaknesses at high mileage.
Diesel Inline-Six
Beefy inline-six diesel — eats up motorway miles, but won't set the pulse racing.
Engine Weaknesses 6
As mileage increases the timing chain stretches and the chain tensioner loses its spring force. Broken plastic guide rails send fragments into the oil sump, which can damage the oil pump.
Symptoms: Rattling or clattering on cold start that improves once warm. Engine warning light.
The turbocharger wears through bearing problems or insufficient lubrication. Particularly at risk with infrequent oil changes or immediate shutdown after full-load driving.
Symptoms: Whistling noises, significant power loss, blue exhaust smoke, oil in the intercooler.
The plastic swirl flaps in the intake manifold break off and can be ingested by the engine. M57 engines built before 03/2004 are particularly at risk — complete removal is widely recommended.
Symptoms: Hesitation at low rpm; power loss; rattling from the intake area; in the worst case engine damage from ingested flaps; no fault code in early stages
Diesel injectors wear at high mileage. Diagnosis via cylinder balance test and return flow measurement. Individual injector replacement possible at around €450 including installation.
Symptoms: Rough running especially at idle (engine "runs like a tractor"), hesitation, increased fuel consumption, white/black smoke.
The M57 EGR valve becomes coked at high mileage. On the M57 cleaning can be done with the valve in situ — an advantage over newer engines. Regular cleaning every 60,000–80,000 km is recommended.
Symptoms: Sluggish throttle response; black smoke under acceleration; rough idle; power loss especially at low rpm
The M57 glow plugs must be replaced as a set. Defective glow plugs stress the DPF through incomplete combustion and can cause secondary damage to the glow plug control unit.
Symptoms: Poor cold-start performance; glow plug warning light on or flashing; increased fuel consumption in winter; fault entries for individual cylinder glow plugs
Vehicle Weaknesses 8
E61 Touring has air suspension as standard. Compressor and air bellows fail frequently — repair costs can exceed the vehicle's value. A new system from BMW costs around 700 € in parts alone.
The optional active steering can rotate the steering wheel up to 90 degrees or lock the steering due to AFS control unit faults. Recalibration or control unit replacement (over 1,000 €) required.
On the E61 Touring with optional air suspension, compressor and air bellows fail regularly. Often both sides at the same time. Rear sags, fault message appears.
Rust bubbles form in the seam between the rear window and boot lid. Occurs even on well-maintained garaged vehicles because moisture gets trapped in the hemmed edge.
The iDrive infotainment system overheats due to a failed cooling fan — system no longer starts or runs with limited function. Fan runs continuously and drains the starter battery.
Aluminium front control arms on the E60/E61 are particularly prone to wear. Regular inspection is necessary as wear affects handling and tyre wear.
Valve cover gasket and oil filter housing gasket become porous on older E60s. Oil smell in engine bay and visible oil traces. On the M57N2 diesel, crankcase ventilation often also causes oil burning.
Rubber bushings in the rear integral arms wear from around 120,000 km and produce creaking noises. Worn shock absorbers and axle bearings are typical age-related issues.