Which E70 engine should you choose?
The E70 came with a wide spread of petrol and diesel engines, and your choice matters more than the trim level. The safest pick is the 3.0-litre straight-six petrol in the xDrive30i (badged 3.0si in early cars). BMW’s N52 engine is smooth, reasonably economical and far less troublesome than the V8s, and it produces around 260 hp — plenty for a family SUV.
The xDrive35i is the sweet spot for many buyers. Early cars (2008–2010) use the twin-turbo N54, while facelift cars from 2011 use the single-turbo N55. Both are strong and refined, but the N54 is known for high-pressure fuel pump failures, injector trouble and wastegate rattle, so budget accordingly or favour the later N55.
The V8s — the 4.8-litre xDrive48i and the twin-turbo 4.4-litre xDrive50i — are fast and effortless, but they are also the most expensive E70s to own. The N62 V8 drinks oil and can suffer valve stem seal wear, while the N63 in the xDrive50i is notorious for oil consumption, injector failures and heat-related wear.
Diesel buyers should look at the xDrive35d, sold from 2009. Its 3.0-litre twin-turbo diesel delivers strong torque and the best fuel economy in the range, though the diesel particulate filter and emissions system need regular longer runs to stay healthy.
Common used BMW X5 problems
Most E70 faults are well documented, which makes them easy to check for on a viewing. Oil leaks are the most common — look for weeping around the valve cover gasket and the oil filter housing, particularly on the six-cylinder petrols. The electric water pump and thermostat are wear items on the turbo petrols and usually fail between 60,000 and 100,000 miles, so ask when they were last replaced.
The xDrive all-wheel-drive system can develop transfer case problems, often announced by a shudder or judder on tight turns at low speed. Air suspension is fitted to the rear of most E70s: listen for a noisy compressor and check the car sits level after standing overnight, as sagging points to leaking air springs.
Inside, test everything. Early cars use the CCC version of iDrive, which can be slow and prone to screen failure; facelift cars from 2009 use the much better CIC system. Check the panoramic sunroof opens fully and look for damp carpets, a sign of blocked sunroof drains. Finally, scan for fault codes — a cheap OBD reader will reveal stored warnings the dashboard may not show.
The pre-purchase inspection checklist
Start with a cold engine. Watch the exhaust on start-up: blue smoke suggests worn valve stem seals on a V8, while a rattling idle on a turbo petrol can point to wastegate wear. Let the car idle and check the coolant temperature climbs steadily and the heater blows hot.
Drive it over varied roads. The gearbox — a six-speed automatic on most cars, eight-speed on later diesels — should shift smoothly with no flaring or harsh changes. Listen for clonks over bumps, which can mean worn bushes or suspension arms, and check the steering tracks straight.
Look underneath for oil and coolant leaks, and inspect the tyres. The E70 runs staggered tyre sizes front and rear, and a full set of quality tyres is expensive, so factor worn rubber into your offer. Ask for a full service history, check the MOT history for recurring advisories, and confirm the air conditioning blows cold — a regas can mask a leaking condenser.
Running costs: what to budget
An E70 is a premium SUV, and its running costs reflect that. Budget for annual servicing, and expect wear items such as brakes, suspension arms and cooling components to cost more than on a 3 Series. Fuel economy ranges from the mid-20s mpg for the six-cylinder petrols to the low 30s for the diesel on a run, while the V8s will return far less around town. Insurance and road tax sit in the higher bands, so check both before committing. Buying the cleanest, best-maintained example you can afford almost always works out cheaper than buying the cheapest car on the market.
Why a service manual helps before you buy
A workshop manual is one of the cheapest tools in an E70 buyer’s kit. It tells you the correct service intervals, the torque figures for common jobs and the step-by-step procedures for the checks above, so you can judge whether a fault is a weekend fix or a garage bill. The E60 5 Series manual covers the same N52 straight-six and N62 V8 engines found in early E70s, while the E90 3 Series manual is the reference for the N52 and N54 engines, and the F30 3 Series manual covers the later N55 engine. With the right manual on your phone, you can walk around a used X5 knowing exactly what to look for — and what it will cost to fix.
Frequently asked questions
What is the most reliable BMW X5 E70 engine?
The 3.0-litre N52 straight-six in the xDrive30i is widely regarded as the most reliable E70 engine, with the later N55 turbo six a close second. The V8s are the least reliable and the most expensive to run.
How long does a BMW X5 E70 last?
With regular servicing, an E70 can pass 200,000 miles. The body and chassis hold up well, but the cooling system, suspension and turbocharged engines need timely maintenance to reach high mileages.
Is the BMW X5 E70 expensive to maintain?
Yes, compared with an ordinary family car. Parts, tyres and labour are all premium-priced, and complex systems such as air suspension and xDrive add to the bill. A thorough pre-purchase inspection and a realistic maintenance budget are essential.
Should I buy a high-mileage BMW X5 E70?
A high-mileage car with a full service history and recent cooling system, suspension and transfer case work can be a good buy. A low-mileage car with no history is a bigger risk than a well-kept car with 150,000 miles on the clock.
