BMW X6 M (E71) buying guide

There are two versions to choose from. The original E71 X6 M ran from 2010 into early 2012, and the facelift (LCI) arrived in March 2012 with a tweaked nose and optional LED headlights. Each has its own page: the E71 X6 M and the E71 X6 M LCI. If you want the newer cars for comparison, see our F86 X6 M guide.

A five-seat layout became available in the US for 2012, and earlier cars are four-seaters only. Settle whether you need the rear middle seat before you narrow the search.

Build date matters less than what was done to the car. BMW's free injector replacement covered cars built through April 2013, and two separate service actions replaced the crankcase vent line on every X5 M and X6 M. A dealer can tell you what was done to a given car, so a later build is no substitute for that check.

For equipment, Auto Express suggests looking for Nappa leather, the Media Package, active steering and self-leveling rear air suspension.

Heat in the engine bay is blamed for several of the faults below. The first two carry the largest repair estimates the sources give.

Turbocharger failure

The two turbos sit in the hot V, where heat ages seals and the oil and coolant lines. A turbo starved of oil can seize, with blue or white smoke, lost power and boost faults. M Buyers Guide rates it high severity and estimates the repair at $8,000.

Valve stem seals

Heat hardens the seals, so oil leaks past the valves and burns. The engine can stay in the car, but the job is long, and the estimate is $6,000. Per BimmerBench, BMW's bulletin calls for a full oil-consumption test before seals are replaced when heavy oil use is the only complaint.

Injector failure

The early piezo injectors fail, often on a cold start, with rough running, misfires and a warning light. BMW's free service action replaced injectors on cars built through April 2013, and coverage on 2010 to 2012 cars was extended to 10 years or 120,000 miles, which has now run out. One injector costs about $1,000 and all eight about $4,500.

Coolant leaks

The cooling system is large and plastic-heavy, and pumps, hoses and pipes can leak or fail with age, risking overheating. Hot-vee coolant leaks are well known, and each is a four-figure bill.

Crankcase vent line

The line can turn brittle and break, which causes rough running. BMW swapped it out across the whole X5 M and X6 M line through two service actions, the first for 2009 to April 2011 and the second for March 2011 to 2014.

Ignition coils and plugs

Coil failure on S63 engines under 30k miles is described as common, possibly from engine bay heat. Stock plugs last about 40,000-50,000 miles and coils about 50,000-70,000, according to BimmerBench, which also lists misfires from coils and injectors.

Oil use and rod bearings

S63 engines use oil between changes, and you may find wet oil behind the engine or near the turbos. Rod bearing wear is discussed on early cars, so a car that drinks oil deserves more questions than a quick top-up.

Engine-bay partitions

Heat can break up the partitions in the engine bay. Water then reaches the engine and causes electrical faults.

M Buyers Guide puts an oil service at about $275, due yearly or every 7.5k miles, and spark plugs at about $600 every 30k to 60k miles. Tires come to about $1,800 a set and a brake job about $2,200.

BimmerBench has plugs due every 3rd oil service on M models rather than every 6th. AutoTrader.ca advises assuming a used X6 M needs tires, pads, rotors and a full fluid service until records show otherwise.

The big bills sit in the engine: $8,000 for a turbo repair, $6,000 for valve stem seals and about $4,500 for all eight injectors, on the same source's numbers. Our BMW X6 M price guide tracks the purchase side, and these are the bills that follow. The cheapest X6 M listings are where such bills tend to matter most.

Either version can work, provided the paperwork shows the valve stem seals, injectors, crankcase vent line, turbo and cooling work were dealt with. Without it, price that work in. Ownership risk is rated high, and AutoTrader.ca recommends buying through certified pre-owned with an extended warranty and a full pre-purchase inspection.

Walk away from a car with blue smoke on a cold start, wet oil around the turbos or an open water pump recall. Before you pay, have a dealer confirm the recall and service actions are closed and a specialist scan the car for fault codes.