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Engine & cooling

2018 Buick Lacrosse Engine problems

Owners have filed 4 complaints about the 2018 Buick Lacrosse's engine & cooling with NHTSA - 33% of all its complaints, most recently on September 22, 2025. Stalling, loss of power, oil consumption, overheating, head gaskets, timing chains and engine failure.

Complaints
4
Recalls
0
Crashes
0
Fires
0
Injuries
0
Deaths
0

Engine complaints

Acceleration & cruise controlEngine & cooling

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...

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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 accelerator pedal position sensor needed to be replaced. The vehicle was repaired, but the failure recurred. While driving at 55 MPH, the vehicle lost motive power and decelerated to 15 MPH. The message "Engine Power Reduced" was displayed, and the check engine warning light was illuminated. The vehicle was taken back to the same local dealer, where it was diagnosed and determined that the accelerator pedal position sensor needed to be replaced; however, the failure persisted. The manufacturer was contacted, and referred the contact to the NHTSA Hotline to report the failure. The failure mileage was approximately 26,600.

Filed Incident Vehicle speed control · EngineNHTSA 11688843
Engine & cooling

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.

Filed Incident EngineNHTSA 11623656
Engine & cooling

Thermostat failure at 56,000 miles.

Filed Incident EngineNHTSA 11561626
Engine & cooling

If stopped uphill and the auto stop activates, when you release the brake the car can roll back, and the way people stop on top of you these days your car can roll back into them and you have to repair their car. Plus it actually takes more gas than my v8 2016 gmc sierra that doesn't stop when traveling from my fueling location to my home, per the cars own computer system

Filed Incident EngineNHTSA 11160527

Buick Lacrosse engine complaints by year

Lacrosse engine problems, every year

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Source: U.S. National Highway Traffic Safety Administration (NHTSA) complaints and recalls, checked . Complaints are owners' own reports and are not verified. How we use the data

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