BMW 6er GT G32 — Problems & Common Faults

Modular four-cylinder diesel as a direct successor to the N47 — and a significant improvement. The timing chain now sits at the front of the engine (belt side), massively simplifying maintenance and diagnostics. The biggest N47 problem is structurally eliminated. Early examples (2014-2016) still had occasional chain stretch, from 2017 onward this is no longer an issue. The EGR cooler was subject to a BMW recall for potential fire risk — when buying used, always verify the recall was performed. In daily use a very balanced engine: even the base version is sufficient for relaxed driving, the 8-speed automatic pairing (ZF 8HP) is one of the best combinations in the segment. Real-world consumption 5-6 L/100km, documented mileages beyond 300,000 km. Weak points remain DPF with pure short-distance driving and typical diesel issues (EGR carbon buildup, injector wear from 160,000 km). Overall a solid, mature diesel — not maintenance-free, but in direct N47 comparison a different league.

• !! Timing chain elongation on early models (2014–2016) from 120,000 km

  Early B47 engines (2014–2016) are prone to premature chain elongation. The tensioner can no longer compensate. Rattling on cold start is the typical warning sign before chain snap and engine damage.

  Symptoms: Metallic rattling or clattering on cold start; subsides after warm-up; in advanced cases audible during driving; MIL may illuminate
  1,500–4,500 $
  Ad B47 timing chainB47 chain tensionerB47 chainnführung
• !! EGR cooler leak with fire risk (recall) from 100,000 km

  Overheating and leaking EGR coolers can vaporise glycol and trigger self-ignition. BMW recalled affected vehicles. If coolant enters the combustion chamber, hydraulic lock and engine damage are possible.

  Symptoms: Coolant level drops without visible leak; whitish smoke from exhaust; rough idle; MIL; limp mode; rarely smoke from engine bay
  850–4,000 $
  Ad B47 EGR radiatorB47 EGR valveB47 EGR-radiator
• !! Turbo cascade failure from 130,000 km

  Turbocharger develops axial play, blocks oil return and causes cascading damage to rod bearings, crankshaft and EGR cooler. Metal shavings circulate through entire oil system.

  Symptoms: Power loss, whistling under load, increased oil consumption, blue smoke, rough running
  1,500–3,500 $
  Ad turbocharger B47D20turbo repair kit B47

+ 4 more engine weaknesses + vehicle weaknesses

The B57D30 is BMW's most modern inline-six diesel — modular B architecture, aluminum crankcase, single VGT turbo. Smooth and torquey like no other diesel in its class. The EGR system is the Achilles heel: BMW issued a major recall for EGR cooler fire risk — must verify if completed. AdBlue system can trigger engine start lockout when heater module or NOx sensor fails. Timing chain generally reliable, early failures rare but documented on Gen1 (pre-2018). Turbo oil supply line leaks occasionally — oil smell in cabin is the warning sign.

• !! EGR cooler failure from 120,000 km

  EGR cooler can fail and allow coolant into the intake tract. Documented cases of engine damage shortly after EGR cooler replacement.

  Symptoms: Coolant loss, white smoke, engine check light, overheating
  600–2,000 $
  Ad BMW B57 EGR-radiator
• !! AdBlue/NOx system fault (SCR crystallisation) from 100,000 km

  NOx sensors and SCR dosing unit fail after about 100,000 km or through AdBlue crystallisation. Fault code 26F500 is typical. BMW repairs often cost 2,000–4,000 EUR as entire systems are replaced.

  Symptoms: MIL with message 'AdBlue system faulty' or 'Emission system fault'; fault code 26F500; engine runs normally but warning persists
  500–4,000 $
  Ad B57 NOx sensorBMW SCR DosiereinheitBMW AdBlue Tank
• !! Timing chain elongation on early models from 130,000 km

  Early B57 models (from about 2015/16) show chain elongation with rattling noises on startup. Timing chain replacement requires engine removal. Repair costs comparable to the N57. Significantly rarer from 2018 models.

  Symptoms: Metallic rattling on cold start, especially at low temperatures; subsides after warm-up; in extreme cases engine stumble
  1,500–5,000 $
  Ad B57 timing chainB57D30 timing chainB57 chain tensioner

+ 5 more engine weaknesses + vehicle weaknesses

The B57D30 is BMW's most modern inline-six diesel — modular B architecture, aluminum crankcase, single VGT turbo. Smooth and torquey like no other diesel in its class. The EGR system is the Achilles heel: BMW issued a major recall for EGR cooler fire risk — must verify if completed. AdBlue system can trigger engine start lockout when heater module or NOx sensor fails. Timing chain generally reliable, early failures rare but documented on Gen1 (pre-2018). Turbo oil supply line leaks occasionally — oil smell in cabin is the warning sign.

• !! EGR cooler failure from 120,000 km

  EGR cooler can fail and allow coolant into the intake tract. Documented cases of engine damage shortly after EGR cooler replacement.

  Symptoms: Coolant loss, white smoke, engine check light, overheating
  600–2,000 $
  Ad BMW B57 EGR-radiator
• !! AdBlue/NOx system fault (SCR crystallisation) from 100,000 km

  NOx sensors and SCR dosing unit fail after about 100,000 km or through AdBlue crystallisation. Fault code 26F500 is typical. BMW repairs often cost 2,000–4,000 EUR as entire systems are replaced.

  Symptoms: MIL with message 'AdBlue system faulty' or 'Emission system fault'; fault code 26F500; engine runs normally but warning persists
  500–4,000 $
  Ad B57 NOx sensorBMW SCR DosiereinheitBMW AdBlue Tank
• !! Timing chain elongation on early models from 130,000 km

  Early B57 models (from about 2015/16) show chain elongation with rattling noises on startup. Timing chain replacement requires engine removal. Repair costs comparable to the N57. Significantly rarer from 2018 models.

  Symptoms: Metallic rattling on cold start, especially at low temperatures; subsides after warm-up; in extreme cases engine stumble
  1,500–5,000 $
  Ad B57 timing chainB57D30 timing chainB57 chain tensioner

+ 5 more engine weaknesses + vehicle weaknesses

Modular four-cylinder turbo and workhorse of the current BMW lineup. Wide power range from the economical base version up to the punchy top variants. Structurally the best four-cylinder petrol BMW has ever built: timing chain at front, closed oil circuit, Valvetronic variable valve lift. Oil consumption stays under control when BMW-spec oil (LL-01 or LL-17FE+) is used. Typical wear items are the electric water pump (from around 80,000 km) and the high-pressure pump with direct injection. Not an engine to fear — but BMW service intervals are too long; those who care for their B48 change oil every 10,000-12,000 km.

• !! Timing chain guide rail breaks from 60,000 km

  Timing chain guide rail can break; chain jump and engine damage follows. More common on early production years and with spirited driving.

  Symptoms: Rattling, clattering from the engine, sudden power loss, engine damage
  2,000–4,000 $
  Ad BMW B48 timing chainBMW B48 GleitschieneBMW B48 chain tensioner
• !! Oil filter housing leaking — coolant loss from 60,000 km

  Oil filter housing with integrated oil/water heat exchanger leaks. Coolant loss and overheating risk from about 60,000 km.

  Symptoms: Coolant level warning, oil puddle under engine, overheating
  400–1,200 $
  Ad BMW B48 oil filter housingBMW B48 heat exchanger11428643747
• !! Coolant bleed line at cylinder head breaks from 70,000 km

  A plastic bleed line between the cylinder head and expansion tank becomes porous and breaks. Coolant loss follows; the mounting location is difficult to access, so labour costs dominate.

  Symptoms: Dropping coolant level; coolant warning on the instrument cluster; faint sweet smell; no visible puddle under the car
  300–700 $
  Ad BMW B48 coolantleitung cylinder headBMW B48 breather line

+ 6 more engine weaknesses + vehicle weaknesses

Closed-deck aluminium block as standard — a feature normally reserved for racing engines. Water-cooled turbo with mechanical wastegate linkage that rattles at cold start — by design, not dangerous. Barely audible at idle; from 3,000 rpm a rich, deep six-cylinder thrust builds linearly to 6,500. The B58 sounds fuller than the S55 from outside — but inside the motorsport aggression is absent. Dual injection (direct + port) reduces intake valve carbon build-up significantly. The PCV membrane in the valve cover is the known weakness: BMW had to extend the warranty to 15 years. Plastic oil filter housing cracks around 100,000 km — coolant mixes into oil, act immediately. Oil changes every 10,000 km; inspect the cooling system from 70,000 km. Tuning: the closed-deck block tolerates much more boost, which makes the B58 a favourite in the tuning scene.

• !! Oil filter disintegrates — engine damage risk from 30,000 km

  On B58-equipped M140i/M240i the oil filter can disintegrate on first change and distribute filter material through the oil circuit. BMW covers the costs with proven service history.

  Symptoms: Oil pressure warning, metallic noises, engine damage after oil change
  100–8,000 $
  Ad BMW B58 oil filterBMW M140i oil filter
• !! Plastic oil filter housing cracks — coolant/oil mixing from 100,000 km

  The plastic oil filter housing becomes brittle from heat cycling and cracks — often during oil changes from overtightening the filter cap. Coolant and oil mix; engine damage likely if unnoticed.

  Symptoms: Milky oil on the filler cap, coolant loss without visible leak, oil pressure warning, coolant level drops slowly
  400–1,500 $
  Ad BMW B58 oil filter housing KunststoffBMW B58 oil filter housing 11428637215B58 oil filter housing replacement
• !! PCV valve / valve cover membrane failed from 80,000 km

  The PCV membrane in the integrated valve cover tears or hardens from heat cycles. Crankcase builds positive pressure, oil is forced through seals. BMW extended the warranty to 15 years/150,000 miles.

  Symptoms: Whistling or squealing from the engine bay, white or blue smoke, rough idle, oil in the charge pipe or air filter
  800–2,500 $

+ 9 more engine weaknesses + vehicle weaknesses