2018 Buick Encore: What to check before buying

Turbocharger failure is the main pattern. It brings a check engine light, code P0299, reduced power and trouble holding speed. Other reports describe rough running, shaking, stalling and hesitation on acceleration, including power loss in traffic. Timing chain failures strand cars, one at 98,507 miles with crankshaft damage. Accelerator pedal sensor faults trigger limp mode. Oil leaks from the filter housing and turbo oil line also appear. A shortage of turbo oil line parts keeps cars waiting at shops. Some owners say they fall outside the limits of GM's turbo coverage letter.

Oil leaks from the oil cooler pipe, loose turbo hose clamps and turbocharger failure make up these reports. The loose clamps set a check engine light and lower fuel economy, and they come back after being tightened, in one case around 54,000 miles. A defective turbo assembly causes sudden power loss before the engine restarts on its own, and antifreeze burning in the engine is also reported. The oil cooler pipe leak continues until the part is replaced.

Front air bags fail to deploy in collisions. This is the most serious pattern in these reports, with six crashes and eight people injured. They include front-corner impacts, a rear impact and a head-on deer strike, all with no frontal deployment. The other common fault is the passenger seat sensor switching the air bag off while an adult is seated, or an air bag warning light that stays on. Repeat dealer visits do not fix it. One repair quote is $873.19, plus $200 for diagnosis.

Loss of power and failure to accelerate lead these reports, often with a flashing check engine light or a StabiliTrak warning. Repeated turbocharger failures appear, with the supply and return oil lines blamed. Other faults include stalling at speed with a locked steering wheel, unexpected shifts into neutral and a Service AWD light that keeps returning. One parked, unoccupied car rolled away and crashed into another vehicle. Dealers often cannot reproduce the intermittent faults, so they keep coming back.

Power steering, brakes and throttle cut out together while the car is moving. That is the core complaint here and a serious loss-of-control risk. Cars shake or hum before it happens. Warning lights flood the dash, screens flicker, and doors lock and unlock on their own. Some cars shut off completely while driving. One crash with an injury is reported. The fault is intermittent and keeps coming back. Dealers often cannot reproduce it, even after several repair attempts.

The radiator cooling fan keeps running after shutdown and drains the battery. This is the clearest pattern here. In one case a dealer found a fan assembly installed backward and a melted fuse block. Other reports describe a brief total power loss while driving, a no-start with unresponsive computer systems, and a glitching infotainment screen alongside rough running and stalling. Another describes a dash that gets hot with an odor while the climate system will not shut off.

The car speeds up when the brake is pressed, the brakes lock and slow the car while the driver is on the gas, or the engine stalls when coming to a stop. One unintended acceleration case ended in a crash while cruise control was on. In another, a dealer replaced the brake pedal position sensor and then found a loose pivot in the pedal assembly. Stalling at stops leaves drivers exposed to rear-end collisions.

Sudden acceleration and accelerator pedal failure are the two problems reported here. In one, the engine revs hard during low-speed braking, the brake pedal sinks to the floor, and the car surges into a wall. In the other, an Engine Power Reduced message caps speed at 25 mph, and a dealer traces it to a failed accelerator pedal at about 41,000 miles. Both create a crash risk in traffic or tight spaces.

A cracked high-pressure plastic fuel line just ahead of the right rear tire pours out gasoline. That is a fire risk. The repair means dropping the fuel tank and runs about $900 in the report. Separately, rain pools at the fuel filler port and blocks refueling. Only two reports fall under this heading, so there is no wider pattern yet.