2018 Ford Fusion: What to check before buying

Coolant leaks into the cylinders, and the usual outcome is a replacement engine. Reports describe coolant that keeps dropping with no outside leak, misfires on one cylinder, rough running, white exhaust smoke and overheating warnings. Some cars lose power or stall at highway speed. Dealers typically quote a long block or full engine, with estimates such as $7,200 and $9,742. Most failures land between about 60,000 and 100,000 miles, but some appear near 32,000. Owners name both the 1.5L and 2.0L engines, and many say Ford declined to help pay.

Nearly every complaint here is coolant intrusion into the cylinders. The car shudders, runs rough or will not accelerate, often with a flashing check engine light, white exhaust smoke and coolant that drops with no visible leak. Some cars show an "Engine Overheating" message and go into reduced-power limp mode. Diagnoses include a cracked block or blown head gasket, and the fix is usually a new engine. Many failures fall between roughly 84,000 and 91,000 miles. A few owners also report a cracked flex plate after an engine replacement.

Two problems dominate. The first is the same coolant intrusion described under engine, which leads to overheating, misfires, sudden shutoffs and engine replacement. The second is transmission failure. Drivers describe harsh shifts, slipping, shudder, and a car that acts as if it is in neutral while in drive, sometimes during highway merges. Diagnoses include a failed torque converter and full transmission replacement, some between 40,600 and 68,000 miles. A few reports describe a cracked flex plate that rattles near the back of the engine. One crash report blames the car moving unexpectedly in reverse.

The most serious pattern is the engine shutting off while the car is moving. Some cars stall in traffic with a "full accessory mode" message, and one rolled backward on an incline at a light. One crash followed a shutoff in which steering and brakes locked up. The touchscreen module (APIM) also fails, taking the screen, climate controls, backup camera and hands-free calling with it. Other reports include a trunk that pops open while driving, a shift knob that moves on its own, and one fire that started in the trunk at highway speed and destroyed the car.

Power steering assist cuts out suddenly, often mid-turn. The dash then shows warnings for steering assist, AdvanceTrac and hill start assist, and drivers describe narrowly avoiding collisions. A second pattern is a steering wheel that feels loose, wobbles or has play. One mechanic found the connection between the wheel and the column worn nearly round. Some owners also hear creaking when turning in warm weather, or clicking from the column. Several complaints filed under steering actually describe shift system faults or coolant intrusion.

Almost every complaint is about swollen lug nuts. The two-piece capped nuts expand or shed their caps, so a standard socket or the supplied tire iron no longer fits. Shops refuse to rotate the tires until the nuts are cut off or replaced, and owners pay for new ones, with quotes from over $120 to over $250. The bigger risk comes with a roadside flat, when the wheel may not come off and the car is stranded. One unrelated complaint describes a leaking valve stem.

Airbags that do not deploy in a crash are the main concern. Three of the reports involve crashes, with four people injured. They include a frontal hit on a light pole in which the passenger-side airbags stayed in place, and a rear impact while the car was stopped at a light. One of these crash reports also blames brakes that sank to the floor. A separate complaint describes going more than two years without a fix for a Takata airbag after the owner received a notice.

Each of the three complaints describes a different fault. In one crash, the driver's belt did not buckle or retract properly, and the driver was injured even though the airbags deployed. Another owner reports a rear driver-side buckle that has never latched. A third says the unbuckled-belt warning only appears after about 2 minutes of driving. No repeated pattern shows up in this small group of complaints.

The one crash report describes the car lurching forward with sudden force while it crept into a parking space, sending it into a storefront wall. The dealer found no fault codes. The other two complaints describe the opposite problem: the car will not accelerate and makes a boiling-water sound or puffs white smoke. One of those cars was diagnosed with coolant intrusion and a cylinder 2 misfire. A car that will not accelerate while pulling into traffic left one driver nearly hit from the side.