2020 Buick Encore

The 1.4L turbocharged engine shares the same PCV valve cover design with the Chevrolet Cruze and Sonic, and it suffers from the same diaphragm rupture issue. The failed PCV system causes rough idle, increased oil consumption, check engine light with code P06DE, and vacuum leaks. Oil vapors are not properly routed, leading to carbon buildup on the intake valves.

Replace the valve cover assembly with the updated GM design. The PCV valve is integrated into the valve cover and is not separately replaceable. Clear codes and monitor oil consumption after repair. Replace spark plugs if fouled by oil. Reference GM TSB 18-NA-305.

The 6T40 six-speed automatic transmission develops a shudder during light acceleration at 25-45 mph and harsh shifts between gears. The torque converter clutch develops glazing on its friction surface, causing the shudder that feels like driving on a washboard road. Some owners also report delayed engagement when shifting from Park to Drive, especially when the transmission is cold.

A transmission fluid flush with Dexron HP ATF is the recommended first step and resolves the shudder in many cases. Persistent shudder requires torque converter replacement. Reference GM TSB 18-NA-355 for diagnosis. In severe cases with internal clutch damage, a complete transmission replacement or rebuild may be necessary.

The turbocharger wastegate develops excessive play and rattles at idle, producing a buzzing or vibrating sound from the turbo area. Over time, the wastegate may stick open, preventing the turbo from building proper boost and resulting in reduced power, check engine lights with boost-related codes (P0299), and poor acceleration. The issue is most noticeable during cold starts.

Replace the turbocharger assembly, as the wastegate is integrated and not separately serviceable on this unit. Some aftermarket rebuilders offer wastegate actuator replacement, but GM recommends full turbo replacement. Reference GM TSB 16-NA-076 for turbo noise and performance diagnosis.

The rear tail light housings are prone to water intrusion through deteriorating seals, causing condensation inside the lens, corrosion of the bulb sockets, and eventual bulb failure. Owners notice water droplets inside the tail light lens after rain or car washes. The moisture can also corrode the wiring connector, causing intermittent tail light operation.

Remove the tail light assembly, dry it thoroughly, and reseal the housing with silicone RTV or replace the gasket. If the bulb sockets are corroded, replace the entire tail light assembly. Apply dielectric grease to the electrical connector. Some owners drill a small drainage weep hole in the bottom of the housing as a preventive measure.

The front lower control arm bushings wear out prematurely, causing a clunking noise over bumps, loose or wandering steering, and uneven front tire wear. The rubber bushings crack and deteriorate, especially in vehicles driven on rough roads. The wear is often noticeable as early as 40,000 miles.

Replace both front lower control arms, as the bushings are pressed in and not cost-effective to replace individually. Perform a four-wheel alignment after replacement. Inspect the sway bar end links and tie rod ends at the same time, as they may have worn concurrently.