GM releases service update addressing engine noise in 2025–2026 Buick Envision
General Motors has issued a technical fix for owners of the Buick Envision crossover who may notice a distinctive ticking sound coming from the engine. In February 2026, the automaker published an updated service bulletin, PIP6101A, outlining the issue and the recommended repair procedure.
The document describes a condition referred to as a “top-end engine tick” affecting the 2025 and 2026 model years of the Buick Envision. The vehicles involved are equipped with GM 2.0‑liter LSY turbocharged inline‑four. This powerplant isn’t exclusive to the Envision. It’s also used in several other models across the company’s lineup, including the Cadillac CT4, Cadillac CT5, and Cadillac XT4, as well as certain vehicles from Chevrolet and GMC sold in North America.
According to GM’s technical documentation, the ticking noise may be caused by foreign debris inside the engine. Small particles left over from manufacturing can find their way into the hydraulic timing chain tensioner. When that happens, the tensioner may fail to fill with oil properly and becomes too soft. Reduced pressure within the valvetrain can then create excessive clearance, producing a noticeable ticking sound—most often heard at idle or while the engine is running.
To correct the problem, GM instructs dealership technicians to perform a diagnostic inspection. If a mechanic confirms with a stethoscope that the noise is coming from the valvetrain, the next step is to remove the camshaft carrier and inspect the valve rocker arms. If the condition is present, the repair procedure calls for replacing all 16 hydraulic lifters and all 16 rocker arms. The work is covered under the vehicle’s powertrain warranty.
Service bulletins like this are routine for major automakers. Still, the situation highlights how even minor manufacturing debris can affect the operation of today’s tightly engineered turbocharged engines.