BMW 5 Series 520i.
What to Check Before Buying.

The BMW 5 Series 520i suits buyers seeking an elegant executive saloon with lower running costs than six-cylinder alternatives, making it ideal for business users and families who prioritise efficiency without sacrificing the premium badge. The 2.0-litre petrol engine delivers adequate performance for motorway cruising and offers reasonable fuel economy, typically achieving 35-45 mpg in real-world driving. However, the four-cylinder engine can feel less refined than the silky-smooth six-cylinder variants, with more noticeable vibration at idle and under acceleration. When buying a used 520i, check the timing chain for rattling noises on cold starts, particularly on higher-mileage examples, as replacement can be costly. Inspect the service history carefully to ensure BMW's long-life oil service schedules have been followed. Pay attention to the condition of the air suspension on models so equipped, as repairs can exceed £1,000 per corner. Also verify that the iDrive system and electronic features function correctly, and examine the leather seats for wear on the driver's bolster. A comprehensive pre-purchase inspection can identify potential issues before purchase.

The average used car has 3+ known model faults the seller won't mention.