The entry-level diesel in BMW's executive saloon. The 518d uses the same B47 2.0-litre four-cylinder as the 520d, detuned to 150 hp and 350 Nm, paired with the ZF 8-speed automatic. It is a popular company car in Western Europe thanks to low CO2 emissions and excellent motorway fuel economy, regularly returning 5.0 l/100 km or better on longer runs. The B47 is a significant improvement over the troublesome N47 it replaced, with the timing chain relocated to the front of the engine.
Efficient and refined diesel engine
Low running costs for its class
EGR system is recall-prone
AdBlue system can be costly to fix
Buy if: You want an efficient executive cruiser for long-distance use and can verify the EGR recall has been completed.
Avoid if: You mainly drive short urban trips (DPF and AdBlue issues) or want strong acceleration from the base diesel.
Expected Annual Maintenance Costs
Common Problems
EGR cooler can leak coolant internally, mixing with soot and potentially causing fire · more· less
BMW has issued multiple recalls since 2018 affecting B47 diesel engines, including those in the G30 5 Series. The EGR cooler can develop internal leaks where coolant (glycol) mixes with hot diesel soot, which can cause the intake manifold to melt and in rare cases lead to fire. The recall has been extended several times because initial fixes proved inadequate. If the recall has been completed, cost is zero. If out-of-recall and the EGR cooler and intake manifold need replacing, expect €800-1,500 at an independent specialist. Always verify recall status with BMW using the VIN before purchase. After the recall repair, some owners report subsequent EGR valve failures (€300-500) as a secondary issue.
NOx sensors, dosing injector, or SCR catalyst failure triggers warning messages · more· less
The AdBlue selective catalytic reduction system on the B47 uses NOx sensors, a dosing injector, and an SCR catalyst to meet emissions standards. Forum reports show multiple fault codes (80527A, 80527D, 8052CD) appearing typically after 60,000-100,000 km. The most common failure is a NOx sensor (€350-500 per sensor, two fitted). The dosing injector can crystallize and block (€300-400 to replace). In worst cases, the SCR catalyst itself needs replacing (€1,200-1,800). The system can also flag false warnings after using contaminated AdBlue or letting the tank run completely dry.
B47 timing chain can stretch at very high mileage, much less common than on the N47 · more· less
The B47 moved the timing chain to the front of the engine, a major improvement over the N47 where rear-mounted chains were a widespread failure point. On the B47, chain stretch is uncommon and typically only occurs beyond 150,000-200,000 km, often linked to extended oil change intervals or poor oil quality. Symptoms include a rattle on cold start lasting a few seconds. Replacement at a specialist costs €1,500-2,500 depending on whether automatic or manual transmission. BMW-recommended oil change intervals should not be exceeded. This is a low-probability issue on a well-maintained car.
Harsh or delayed shifts when cold, potentially from worn solenoids or low fluid · more· less
The ZF 8HP transmission is generally excellent but can develop harsh cold-start shifting over time. ZF recommends fluid and filter change every 100,000 km, which BMW historically listed as a sealed-for-life unit. Neglecting this service causes the fluid to degrade, leading to harsh shifts. A transmission fluid and filter change costs €300-500 and often resolves the issue. If the solenoids are worn (ZF issued a recall on certain solenoid batches), the mechatronic unit may need repair or replacement at €1,200-2,500. Most cases are resolved with a fluid service.
Diesel particulate filter blocks if regeneration cycles are interrupted by short trips · more· less
The DPF needs periodic high-temperature regeneration, which requires sustained driving at highway speeds for 15-20 minutes. Cars used primarily for short urban trips may not complete regeneration, leading to progressive soot buildup. Early symptoms include increased fuel consumption and a DPF warning light. A forced regeneration at a dealer costs €150-250. If the DPF is too far gone, professional cleaning runs €400-600, and full replacement is €2,000-3,500 including labor. This is primarily a usage-pattern issue rather than a design defect, and highway-driven cars rarely have this problem.
Minor oil seepage from gaskets becomes visible after 80,000-120,000 km · more· less
Oil leaks on the B47 are less dramatic than on some older BMW engines but still occur. The oil filter housing gasket and valve cover gasket are the most common locations, typically developing seepage after 80,000-120,000 km. Symptoms include oil spots under the car, a burning oil smell, or low oil level warnings. The oil filter housing gasket replacement costs €200-400 at an independent specialist. The valve cover gasket runs €300-500. Neither is urgent if caught early but should be addressed to prevent oil from dripping onto hot exhaust components.
Electric power steering rack can develop play or clunking, typically after 100,000+ km · more· less
The G30 uses an electric power steering rack that some owners have reported developing a clunking noise when turning at low speeds or a vague feeling on-center. This typically appears after 100,000 km. The electronic nature of the system means replacement rather than rebuild is usually required, and the new rack must be calibrated using BMW diagnostic software. Replacement cost is €1,500-3,000 depending on whether a new or refurbished unit is fitted. This is not a widespread issue but worth checking during a test drive.
Generally reliable, but verify EGR recall status
The B47 engine is a significant reliability improvement over the N47 it replaced, with most owners reporting trouble-free running to well beyond 150,000 km. The most critical item to verify is whether the EGR cooler recall has been completed, as this is a fire safety issue. Beyond that, the main concerns are emissions equipment (AdBlue system, DPF) which are particularly sensitive to driving patterns. Highway-driven cars with complete service history are very safe purchases.
Recalls and Technical Service Bulletins
EGR cooler leak / fire risk (B47 diesel, multiple extensions 2018-2024)
Critical - verify completed with VIN
Coolant pump electrical connector short circuit risk (2012-2018 models)
Verify completed
Takata airbag inflator (certain 2017 models only)
Verify completed
The EGR cooler recall is the most critical item. BMW has extended this recall multiple times since 2018, and initial fixes proved inadequate. Contact BMW directly with the VIN to verify current recall status. Do not purchase without confirmation that the latest version of the recall repair has been completed.
Warranty Status
Factory warranty (2 years, from Nov 2016: 2+1 years)
Expired on most used 518d G30 models
Rust perforation warranty (12 years)
May still apply to 2017+ models until 2029+
EGR recall
Free repair regardless of warranty status
All 518d G30 models are outside their original factory warranty. The EGR cooler recall is a safety recall and will be performed free of charge at any BMW dealer regardless of warranty or age. Extended warranty packages are available through BMW and third-party providers.
This report is for informational purposes only and does not constitute professional advice. Estimates may be inaccurate. Always have a qualified specialist inspect the vehicle before purchase. We accept no liability for decisions made based on this information.