 The BMW 5-series is a popular mid-size combination of prestige 7-series styling and V8 mechanicals at the top end while offering the more frugal sixes and agility of the popular 3-series at the entry level As the last 5-series before the new BMW look, the E39 stands alone with its more traditional BMW styling. Joe Kenwright unravels what can be a confusing model range. BMW used car e39 Checklist* Radiator: early models can suffer thermostat and radiator faults. Watch the temperature gauge and listen for the engine fan. If it cuts in soon after start-up, walk away. * Water pump: these fail in older cars - even those with low annual mileages. Some say it's a design fault, with 'plastic' impellors in the pump being the weakness. * Engine: the 520i, 523i and 528i models up to September 1998 can suffer premature engine bore wear. BMW replaced many units for free, so check service records. * Windows: electric window regulators fail. Ensure all operate, including the 'one touch' function - although if this is wayward, it can be reset by holding the button in 'close' position for 30 seconds. * Wheels: front wheelbearings have been known to wear prematurely on models that are driven hard or those that have been fitted with excessively large alloy wheels. | 
