2020 GMC Yukon: What to check before buying

Valve lifters collapse, most often on the 6.2L V8, and wear down the camshaft. Warning signs include ticking or knocking, cylinder misfires, rough running, and metal shavings in the oil filter. Many reports say there was no warning at all. Several engines quit at highway speed, and drivers had to coast to the shoulder. One complaint is crash-related. Failures cluster between about 59,000 and 118,000 miles. Repairs range from about $8,000 for lifters and camshaft to $26,000 for a new engine. Owners say the lifter recall for later model years leaves out the 2020.

Coolant goes missing again and again, with white smoke from the exhaust, a coolant smell, and a check engine light. The light goes out once coolant is topped up. Owners suspect a head gasket or lifter problem. The other report is really about the transmission. It slipped out of gear at about 65 mph and the car lost power. Afterward the car would not go into Park and needed a new transmission. The check engine light came back after the repair.

Transmissions slip, shudder, jerk from a stop, and then fail completely. Many cars lose power mid-drive, sometimes on the interstate, often with no warning light. Reported failures fall between about 82,500 and 120,000 miles, and several come soon after the warranty ends. Some reports blame the torque converter. In one case the vehicle kept moving in Park and showed a transmission overheating message. Replacement 10-speed units are back-ordered for months. A few complaints here describe sudden engine failure, and one reports a faulty 4WD switch that engaged 4WD while reversing.

Power steering cuts out when the engine seizes while driving. In one fire-related report the engine stalled on an exit ramp at about 30 mph and the steering assist went with it. Smoke then rose from the engine bay when the driver tried to restart. The other report describes a wobbly wheel that pulled to either side and made the car hard to steer. A failed rack and pinion was found at about 107,000 miles, and the replacement part was not available.

Power brake assist drops out, so the pedal takes much more force to stop the car. One case came after about 5 hours of driving in 100-degree heat. Assist was gone for at least 20 miles before it came back on its own. Another report pairs heavy braking with a "Service Brake System" message on the instrument cluster. That report also describes the engine shutting off in a busy intersection.

Moisture gets past faulty light seals and corrodes the main light board, and the lights suddenly stop working. A separate report describes the navigation screen flickering, going black, and jumping between USB, radio, and the home screen. That owner says the problem sometimes affects the turn signals and that the USB port under the armrest gets very hot.

The engine shuts off while driving, in one case right after the A/C button was pressed. Knocking, shaking, high revs, poor shifting, and a reduced engine speed warning follow, and the car will not go past 30 mph. The dealer found nothing wrong. Another report describes messages saying the key fob was not detected, plus a low battery light, which come and go. That car then made a loud bang and a steady clunk at idle and had to be towed.