*Median odometer reading when the problem happened, where owners gave one. One complaint can name several problem areas.
Fuel/propulsion system
When I get to a stop sign, and a stop light, when trying to accelerate after a complete stop, the car would struggle to accelerate to go forward. Where the shifting gears would start blinking, and the warning lights (engine power reduced, engine light, and the traction safety collision light) would display itself making it misfire and impossible to even go forward while pressing the gas pedal. It put me and other drivers at a safety risk because it would roll backwards after taking my foot off the breaks to accelerate where it would almost hit drivers behind me at the stops as well as them almost mistakingly hitting me in the back when my break lights stop reflecting when trying to…
Nov 11, 2025Vehicle speed control › Accelerator pedal
The contact owns a 2018 Buick LaCrosse. The contact stated the hand controls were not working properly. While driving, the accelerator pedal was depressed, but the vehicle failed to respond. The engine power reduced message was displayed, and the check engine warning light was illuminated. After several attempts, the codes were reset, and the vehicle worked as designed. The contact linked the failure to the Special Coverage Campaign: N182188250. The vehicle was taken to an independent mechanic who disconnected the hand controls and informed the contact that the controls were operating as designed. The vehicle was taken to the local dealer, where it was diagnosed, and determined that the…
Apr 1, 2023 · 26,600 milesEngine
The 3.6 liter engine in my 2018 Buick Lacrosse Avenir only has 53,939 when we experienced a thermostat failure. The engine temperature was dead cold, and the dual electric fans were running non-stop. When I scanned the trouble code, I found PO128 which points to a faulty thermostat. Because the thermostat is buried under the intake manifold, we had the local Buick dealership replace it at a cost of over $800.00. I don't feel that a car with so few miles should be experiencing a thermostat failure. But this seems to be a common problem with the GM 3.6 liter motor according to a number of Buick forums that I read after the problem occurred.
Oct 26, 2024Power train
The contact owns a 2018 Buick Lacrosse. The contact stated while driving at an undisclosed speed, the vehicle hesitated to accelerate while the accelerator pedal was depressed. The contact pulled over and checked underneath the vehicle. The contact discovered that the START/STOP accumulator endcap bolt had detached, causing transmission fluid to leak onto the ground. The vehicle was towed to the residence. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The contact stated that in 2021, he detected an abnormal fuel odor coming through the air vents while driving. The brake pedal also stuck while depressed, and the rear brake pads needed to be replaced…
Jun 3, 2024 · 161,188 milesEngine
Thermostat failure at 56,000 miles.
Dec 4, 2023Electrical system
The contact owns a 2018 Buick Lacrosse. The contact stated that the key fob failed to open the doors and the vehicle was unable to be restarted. The failure had recurred on several occasions. The contact stated that the batteries in the key fob were replaced but the failure persisted. The local dealer was notified of the failure, but no assistance was offered. The manufacturer was not yet contacted. The failure mileage was 100,000.
Nov 6, 2023 · 100,000 milesFuel/propulsion system
I have brought my 2018 Buick Lacrosse to two different Buick dealerships who say that even though a special instruction letter was recognized and a recall was observed, because my check light went out and the codes on the car where cleared, they will not fix either recall. On three different occasions, the car slowed down to a crawl speed, the check engine light went on and the brakes applied themselves. Also across the dash was displayed 'service transmission'. I thought it was the accelerator pedal position sensor, but it may be a transmission problem. I've had it towed on three different occasions and had the battery replaced. Neither dealership will not fix the problem, however.
May 4, 2023Vehicle speed control
When I tried to stop at the traffic light, the car suddenly accelerated and went forward. At that time, the car brake was engaged. On the same day; When I tried to go forward at the traffic light, the car suddenly accelerated. The dealer service center said, "We cannot find any issue with the transmission."
Jan 18, 2022
Owner complaints are submitted to NHTSA by the public and are not verified. Shown as filed (NHTSA removes personal details); long reports are shortened.
