BMW 5 Series 525i.
What to Check Before Buying.

The BMW 5 Series 525i suits buyers seeking a refined executive saloon with strong performance and lower running costs than six-cylinder alternatives. This 2.5-litre petrol variant delivers smooth, responsive power ideal for motorway cruising and business use, whilst offering reasonable fuel economy for the class. The 525i is known for its excellent straight-six engine reliability when properly maintained, though earlier models can suffer from cooling system issues including water pump and thermostat failures. When inspecting a used 525i, check the service history meticulously for evidence of regular oil changes using BMW-approved specifications, as this engine is sensitive to poor maintenance. Examine the cooling system thoroughly for leaks and ensure the expansion tank shows no cracks. Test the automatic gearbox for smooth changes without hesitation or slipping, and listen for any unusual noises from the rear differential. Verify that the electronic systems function correctly, particularly the parking sensors and sat-nav if fitted. A pre-purchase inspection through Folt can identify potential issues before you commit to buying.

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