Despite the price and BMW’s reputation, this series of X5 was not without its problems. Specific to the diesel-engined versions was a raft of things to watch out for when shopping for a second-hand X5. Those start with a poorly designed intake system which used small flaps in each inlet trat designed to create better air and fuel mixing and, therefore, more complete burning of the fuel. The problem was that these little flaps were secured by two screws each, and these could become loose and fall into the engine with catastrophic results. In some cases, the screws could even migrate into the turbocharger unit, destroying it. Like many other brands of modern turbo-diesel, the X5 could also be afflicted by problems caused by a blocked Diesel Particulate Filter (DPF). If the vehicle was used for urban work rather than highway running, the DPF could become clogged and unable to regenerate itself. Any X5 diesel with a `Service Engine Soon’ light illuminated on the dashboard is a potential problem child. The car’s exhaust gas recirculation valve could also leak, causing faults within the emissions-control system, while the electronics associated with the fuel injectors could also be damaged by water entering the engine compartment. Beyond the diesel engine, the rest of the X5 package was not without problems, either. Those can include electronic issues, poor water sealing around the body, noisy suspension and problems with petrol-engined variants as well. Fundamentally, this was not BMW’s finest hour quality-wise. It’s also worth noting that even though the BMW brand is a German one, this generation of X5s was manufactured in South Carolina in the USA.