2018 BMW X5: What to check before buying

Almost half of these complaints are about recall 24V608000. Owners got the notice, but dealers had no parts to do the repair. The failures that do appear show up around 69,000 to 74,000 miles. Owners describe cracked intake manifolds and failed EGR coolers with black smoke or repeated low-coolant warnings. They also report a thermostat stuck open that damaged the transmission oil cooler, and a failed turbocharger with blue smoke at startup. In one case an EGR repair failed again within days. Some owners were told their VIN was not covered by the related recall or bulletin.

Burning smells and smoke from the front of the engine bay appear here. One owner found a melted intake manifold with holes in it and a reduced-power warning. On the plug-in hybrid, the AC compressor can fail badly and spread metal through the AC system. That also turns on the check engine light and cuts electric drive power. Another complaint is mostly about a long recall repair. That car broke down with family aboard and sat at the dealer for an extended period.

Most of these complaints are about two diesel recalls. Under 21V586000, owners waited months because parts were not available. Under 21V907000, the EGR cooler problem came back after the recall repair. Symptoms include coolant loss with no leak found, and white smoke and embers coming from the EGR cooler and intake manifold. Some owners report sudden loss of power at highway speed, including a drop from 75 MPH to crawling speed. In that case the replacement throttle valve did not stop the problem, which returned at 61,000 miles. Stalling while driving also appears.

The engine shuts off while driving, with no warning, sometimes in the middle of freeway traffic. One owner says the high-pressure fuel pump blew apart and sent metal through the whole fuel system, even though the pump had already been replaced under a recall. Another says the fuel system failed twice, two years apart, and was replaced both times. Owners also describe stalling or engine flutter when turning at low speed. In the reported failures, the stalls leave the car stuck in active traffic lanes.

Sudden loss of power is the main pattern. The SUV stalls in traffic or slows rapidly on the freeway, often after a "drivetrain malfunction" warning, and some cars will not restart. Reported failures include a transmission that stopped driving the car near 72,000 miles and a loose front driveshaft. On the xDrive40e hybrid, owners report Electric Motor Electronics (EME) failures that leave the car inoperable. They also report long waits for the recall 24V-608 coolant pump connector fix because dealers had no remedy available. Several reports describe near-crashes while changing lanes or merging.

On the plug-in hybrid, EME failure is the most serious report. The car can lose all electrical power, with stiff steering, no throttle and reduced braking, and owners were quoted repair costs close to the car's value. A rear soft-close door can open by itself on the freeway and refuse to stay shut. Rodents chewing the wiring can set off steering, collision-warning and chassis faults. Other complaints describe a passenger-side blind-spot monitor that misses vehicles and replaced auxiliary heater and high-voltage parts.

When the air suspension fails, the ride turns extremely bouncy and harsh. Owners see a "Drive Moderately" chassis warning, and the car rocks hard over uneven pavement. Owners say this makes the car hard to control and unsafe for passengers. One owner reports a rear air spring giving out, with others saying failures under 60,000 miles are common. Shoppers describe test-driving used examples that bounced badly over minor bumps. Owners report no recall for this problem, and some say they were sent to expensive sensor repairs.

Tread separates from the tire at highway speed, and the failure damages the bodywork around it. One owner had two run-flat blowouts at 80 MPH in three months, on a rear tire and then a front tire. The tire warning light did not come on until after each tire had blown. Damage from a single blowout reached more than $10,000. These are sudden failures at speed, with real loss-of-control risk, rather than gradual wear complaints.

Above about 40 to 50 MPH, the steering turns twitchy and develops noticeable play. The SUV wanders left and right and then snaps back with a jerk in the wheel. Owners compare it to driving in a strong crosswind, and it makes staying in the lane hard. It is worst when the front end goes light, such as over overpasses or rolling roads. A dealer inspection found nothing mechanically wrong.