"Is the 5 Serisi 520i reliable, and what should you check?"
The most frequently mentioned issue when buying a used BMW 5 Series 520i 2015 (F07 / F10 / F10M / F11 / LCI): Timing chain stretching/breakage and bearing damage from debris. Oil leaks and consumption are also commonly reported.
Engine: N20
N20B20B · 520i · Used in this car from 2011-2017
Strengths
Relatively low fuel consumption
Good potential for chip tuning
Watch-outs
Timing chain has low service life
Frequent leaks from under valve cover
Plastic pipes have short lifespan
Known engine issues
Timing chainThe most famous weak point of this engine is the modest service life of the timing chain, sometimes it lasts less than 80,000 km. Note that units after 2015 have a longer service life.
Oil pump chainAnother widespread problem of early engines was the breakage of the oil pump chain with fatal consequences. A new thicker chain appeared in September 2012.
Piston destructionN20B20A engines with compression ratio 10.0 are easily tuned and run without much trouble, but N20B20B engines with compression ratio 11.0 suffer from detonation after chip tuning.
Listed from most frequently reported, each with its source.
Timing chain stretching/breakage and bearing damage from debris
Often reported
In the 520i's 2.0 N20 engine (184 HP), there are numerous reports of premature timing chain stretching and wear of guides/tensioners. Debris from worn guides can enter the oil circuit, clog the oil strainer, reduce oil pressure, and lead to severe bearing damage (bearing seizure).
Timing chain
Oil leaks and consumption
Often reported
Recurring oil leaks at typical gaskets and connection points (oil pan/valve cover gaskets, oil filter housing) and in some cases significant oil consumption are reported for the N20 engine.
Engine Internal
High-pressure fuel pump (HPFP) issues
Often reported
Abnormalities in the high-pressure fuel pump (HPFP) can cause extended cranking, power loss, misfires, warning lights, and limp mode. Symptoms typically appear at higher mileage.
Fuel System
Turbo and wastegate issues
Often reported
Turbocharger failure is not common on the N20 engine, but on high-mileage or modified/chipped vehicles, wastegate rattle, performance loss, and erratic turbo boost behavior have been reported.
Turbo
BMW 5 Serisi 520i technical specs
BMW 5 Serisi 520i (2015): boot 520 L; fuel use 6,8 l/100 km (urban 9 l/100 km · extra-urban 5,5 l/100 km); 0–100 in 7.9 s.
Boot capacity
520 L
Fuel consumption
6,8 l/100 km (urban 9 l/100 km · extra-urban 5,5 l/100 km)
What should I look for when buying a BMW 5 Series 520i?+
When buying a 2015 520i, check the service history, test drive, and look for engine/transmission warnings. The most commonly reported issues: timing chain stretching/breakage and bearing damage from debris; oil leaks and consumption; high-pressure fuel pump (HPFP) problems.
What are the chronic problems of the BMW 5 Series 520i?+
The most commonly reported issues: timing chain stretching/breakage and bearing damage from debris; oil leaks and consumption; high-pressure fuel pump (HPFP) problems.
Is the BMW 5 Series 520i reliable?+
Rather than a simple yes/no, it's best to weigh the proven pros and cons together. This page lists 4 verified findings.
How does Carbeak collect data?+
The cards on this page are derived from Difetti fault database records; compatibility between the source vehicle and target vehicle is verified by brand, fuel type, engine, and generation. Topics with insufficient evidence are not shown.