Some Buick LaCrosse owners report experiencing slow acceleration due to various potential issues, including clogged air filters, dirty mass air flow sensors, and clogged fuel filters. These problems can lead to sluggish starts and delayed responses when pressing the accelerator. Additionally, some owners have noted that jerking during acceleration may indicate a misfire, while reduced engine power in 2010 models can sometimes be improved by applying electric grease to the throttle body connector and gas pedal assembly electrical connectors. Furthermore, a weak battery or malfunctioning alternator may also contribute to acceleration problems. It is crucial for owners to consider these factors to effectively diagnose and resolve slow acceleration issues in their Buick LaCrosse.

Some Buick LaCrosse owners report experiencing starting failures, often attributed to weak or dead 12v batteries, which can be diagnosed through a battery voltage test. Additionally, some owners encounter persistent transmission slip issues even after multiple sensor changes, potentially caused by dirty mass air flow (MAF) sensor elements that lead to incorrect engine load calculations. This can result in symptoms such as transmission slip codes, burnt transmission fluid, and low transmission line pressure, ultimately risking transmission failure. Furthermore, while the Buick LaCrosse is generally viewed as reliable from 2008 to 2019, some owners of early models with the 6-speed automatic transmission report shifting hesitations and jerky gear changes. Addressing these concerns promptly is essential for maintaining the vehicle's performance and reliability.