Buick Park Avenue hard transmission shifting and sputtering after 30 minutes of driving on Buick Park Avenue

Some Buick Park Avenue owners report experiencing hard transmission shifting and sputtering after about 30 minutes of driving. These issues often manifest as hard shifting once the vehicle warms up, particularly during stop-and-go traffic or under medium to hard acceleration. Some users have noted excessive slamming into gears before the problem resolves itself, along with symptoms like erratic shifting, delays, and clunking noises, which may indicate problems with the transmission pressure control solenoid. Regular maintenance, such as flushing the transmission and changing the filter, is recommended to mitigate these shifting issues, and replacing faulty pressure control solenoids may also help. Additionally, some owners have opted for fluid flushes or filter changes to maintain transmission health. In certain cases, a firm shift similar to vehicles with a shift kit has been reported, and issues like a bad valve or faulty shift solenoid could contribute to these problems. It is advisable for owners to consult a qualified technician for a thorough diagnosis and appropriate repairs to ensure the vehicle operates smoothly.