2020 Buick Encore GX Engine Problems

I am submitting this complaint regarding several serious mechanical and electrical issues with my 2020 Buick Encore GX that raise significant concerns about the vehicle's reliability and safety. Most concerning, I was recently informed by the dealership that my vehicle requires another transmission replacement, despite having the transmission replaced in 2024. I was also advised that I would need to pay for an additional diagnostic inspection because technicians discovered oil leaking through the lines, which appears to have contaminated engine components. According to the dealership, metal particles have been found within the engine, causing it to malfunction. They have stated that they are unable to determine the source of the contamination at this time. In addition to these major mechanical concerns, I am experiencing several electrical and system malfunctions, including: The passive keyless entry system does not consistently unlock the doors using the exterior door handle, even with a brand-new battery installed in the key fob. The vehicle repeatedly displays a "Shift to Park" warning even though the gear selector is already in the Park position. The vehicle continues to display brake-related alerts and notifications indicating that the brakes need to be serviced or replaced, despite having brand-new brakes installed. These ongoing issues have resulted in repeated repair costs, loss of confidence in the vehicle, and concerns about my safety while driving. The transmission failure occurring shortly after a previous replacement, combined with unexplained engine contamination and persistent electronic malfunctions, suggests there may be underlying defects that warrant further investigation. I respectfully request that these issues be thoroughly investigated to determine whether they are related to known manufacturing defects or warrant a safety recall or other corrective action. I also request that Buick review my repair history and provide appropriate assistance.

NHTSA ID

11752226

Incident

Jul 18, 2026

2020 Buick Encore GX; pulling out of a service station, my check engine light illuminated, and message on cluster stated: Engine Power Reduced. I loss throttle response for accelerating. Accelerator pedal was pushed to the floor and no acceleration. Vehicle entered limp mode. Drove 15 miles from service station to my home, in limp mode, unable to accelerate. Called a technician mechanic who check for Diagnostic Trouble Codes; DTC P0299 Turbocharge/Supercharge "A" Under boost condition; is Confirmed, Pending, and Permanent code. Loss of power to Power Train, unable to accelerate.

NHTSA ID

11718640

Incident

Feb 16, 2026

The contact owns a 2020 Buick Encore GX. The contact stated that while driving at an undisclosed speed, the vehicle began to shake with abnormal sounds coming from the engine compartment. The check engine warning light was illuminated. The vehicle was taken to the dealer, where it was diagnosed and it was determined that the turbocharger had failed and needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and referred the contact to the dealer for further assistance. The approximate failure mileage was 51,220.

NHTSA ID

11695087

Incident

Oct 22, 2025

Mileage

51,220 mi

I was at a stop light and the light turned green, I preceded to press the accelerator, I was just starting to move forward and the, peddle seemed to take over with my assistance went all the way down and began speeding up. I tried breaking and the car just kept going and not wanting to slow down and kept gaining speed, I had to put car in neutral and turn engine off. Same day, same trip about 4 miles down the road, I began to slow down (35mph) due to a turning vehicle and when I was clear to accelerate once again, it happened again, again, I tried the breaks, and the car kept fighting the break and kept gaining speed, once again I had to put the car in neutral and turn off the engine, the speeds reached 65 mph. before I was able to place in neutral and turn off the engine. No warning lights, car ran normally until those terrifying moments, no check engine lights on before or after the above experiences. My husband and I's safety was put at risk due to the road's travelers and Deadmans curves and cross sections, it put us at risk with a higher chance of crashing into a vehicle or accelerating before being able to make a turn safely. As soon as I made it home, I called the Buick service center and delivered the car the following morning to the service technician. It is at the Ross Downing Service Station today.

NHTSA ID

11645021

Incident

Feb 25, 2025

This is a new issue. Upon exiting my car last night. My car would not shift into park. Everytime I cycled the engine and shift to different gears then park. The car stated it need to be shifted into park still. Without it being in park The car could possibly roll down the hill. Also without it being able to be shifted into park. It continued to flash and keep lights and warning sign on. If not being able to shift into park. I could not leave my car until it recognized the car was in park. The car battery would have drained.

NHTSA ID

11636882

Incident

Jan 18, 2025

My vehicle is undrivable. Multiple times per trip the check engine light comes on and I see multiple messages come on the driver information center. These are: Service ESC Reduced Power Service Adaptive Steering System The codes that come up are: P0089 for low fuel pressure P00C6 This results in an immediate speed reduction nearly causing multiple collisions with people following me on the highway. As a result I have been using a code reader to clear the codes so i can continue driving. I refuse to drive on busy highways so I am always forced to drive back roads. This needs to be figured out ASAP!

NHTSA ID

11631056

Incident

Dec 16, 2024

The contact owns a 2020 Buick Encore GX. The contact stated while driving at various speeds, the vehicle lost motive power while depressing the accelerator pedal. The check engine warning light was illuminated. The vehicle had been taken to the dealer on several occasions, and several repairs were performed on the vehicle. The contact stated that the turbo was replaced twice; however, the failure returned after the repairs. The vehicle remained in the possession of the dealer for a month and the dealer determined that the mechanical outline was incorrect, and that the turbo had been installed incorrectly. The manufacturer was notified of the failure but offered no assistance. The vehicle was repaired; however, the contact expressed concern that the failure might occur again, and was fearful of driving the vehicle. The failure mileage was approximately 60,000.

NHTSA ID

11616343

Incident

Apr 1, 2024

Mileage

60,000 mi

I was driving on the interstate on June 7, 2023 heading to work doing the speed limit of 60 MPH and all of a sudden the check engine light came on and a message stated "Engine Power Reduced" and the engine literally dropped engine power immediately and thankfully there was nobody right behind me and I was able to get off the interstate to a safe place. I called the Buick GMC dealership where I purchased the vehicle and they said to bring it in. They pulled codes on it and it gave a code of "engine under boost" and they said they ran tests on it and could not find anything wrong after 3 days at the shop, they did a software update and told me to come and pick it up. Then not even a week later, I was driving and out of nowhere came the same engine light, message read "engine power reduced" and the engine lost power immediately and I called the Buick GMC dealership again and they said to bring it back in and it's there now. I called today to check in and they said they are going to test the Turbo on it and order parts, etc. but they still do not have a definitive answer as to what's wrong with it yet. I bought my 2020 Buick Encore GX new in November 2020 and it has about 26,000 miles on it. No recalls have been made on my VIN model - I am afraid to even drive this car again and get stuck somewhere away from help or at night - someone could have rear ended me when I lost power on the interstate doing 60 MPH and killed me!!!

NHTSA ID

11528408

Incident

Jun 21, 2023

I was driving on the interstate on June 7, 2023 heading to work doing the speed limit of 60 MPH and all of a sudden the check engine light came on and a message stated "Engine Power Reduced" and the engine literally dropped engine power immediately and thankfully there was nobody right behind me and I was able to get off the interstate to a safe place. I called the Buick GMC dealership where I purchased the vehicle and they said to bring it in. They pulled codes on it and it gave a code of "engine under boost" and they said they ran tests on it and could not find anything wrong after 3 days at the shop, they did a software update and told me to come and pick it up. Then not even a week later, I was driving and out of nowhere came the same engine light, message read "engine power reduced" and the engine lost power immediately and I called the Buick GMC dealership again and they said to bring it back in and it's there now. I called today to check in and they said they are going to test the Turbo on it and order parts, etc. but they still do not have a definitive answer as to what's wrong with it yet. I bought my 2020 Buick Encore GX new in November 2020 and it has about 26,000 miles on it. No recalls have been made on my VIN model - I am afraid to even drive this car again and get stuck somewhere away from help or at night - someone could have rear ended me when I lost power on the interstate doing 60 MPH and killed me!!!

NHTSA ID

11528407

Incident

Jun 7, 2023

The contact’s mother-in-law owns a 2014 Jeep Cherokee. The contact stated while his mother-in-law was driving at an undisclosed speed, the check engine warning light illuminated. The vehicle was taken to the dealer where it was diagnosed that the PCV valve needed to be replaced. The vehicle was not repaired. The contact stated that on another occasion while his mother-in-law was driving, the vehicle started sputtering, overheating, and lost motive power. The vehicle remained at the location. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 75,000.

NHTSA ID

11492911

Incident

Nov 9, 2022

Mileage

75,000 mi

I have only had the vehicle for a year. On multiple occasions the vehicle feels like it is slipping gears (more often when the autostop feature is turned on). On multiple occasions the vehicle has stalled out and would not do anything when pressing on gas- didn't even rev, did absolutely nothing. These stall outs happened crossing highways, at stop lights, stop signs, etc. There were no warnings prior to the incidences, though the vehicle did through an engine/transmission code afterwards, the code would go away. The first several attempts of taking it to the dealership (last year) as it is still under warranty- it was not checked. i was simply told it was a "glitch" and it was fine. They did not record in their system that i requested it to be checked either apparently. They only recorded that i brought it in for an oil change. They only checked into it this February after my boyfriend told them what it was doing. They kept it and replaced one part in the transmission. The vehicle continued to have the same issues and threw a code withing the first 5 minutes after picking it up. I took it back in- and they said it was doing the issues because of the code it threw. I told them it was doing it again before it threw the code. They said it simply needed a line vacuumed out, and then gave it back to me. It continued to have the same issues and stalled out again causing me to roll backwards onto the highway-into traffic. I took it back again. They kept it, and then told me they'd be replacing the entire transmission, but it is on backorder. Still no time frame when it will be repaired. They then told me i could have my car back and continue to drive it until the transmission comes in?!? I said no- it isn't safe, I just told you what happened and i could have been hurt or killed. I am not driving it, especially when i have my son to drive around as well! I have been without my car for at least a month now. I am paying for a car that i don't even have/can't drive.

NHTSA ID

11461685

Incident

Apr 10, 2021

CAR HAS LESS THAN 30 (THIRTY) MILES ON IT; GARAGED SINCE PURCHASE BC OF PANDEMIC; STARTED OCCASIONALLY; BATTERY DEAD WHEN I TRIED TO GO OUT LAST WEEK; CHARGED BATTERY; DIED AGAIN; CHARGED AGAIN; CHECK ENGINE LIGHT ALERTED ONSTAR, WHO SENT EMAIL STATING PROBLEMS W/ENGINE & TRANSMISSION SYSTEM, POSSIBLE ISSUES W/FUEL MANAGEMENT SYSTEM, EMISSIONS CONTROL, MISFIRE CONDITION... ONLY 30 MILES! NEW CAR! JUST DROVE HOME FROM DEALERSHIP AND PARKED IT. TRIED CHATTING W/BUICK CUSTOMER EXPERIENCE, BUT THEY CUT ME OFF 3 TIMES OVER 2 HOURS, SO I GAVE UP THAT EXERCISE IN FUTILITY. DEALERSHIP IS UNPLEASANT; TRYING A DIFFERENT DEALER. GOOGLED RECALLS. THIS SOUNDS LIKE THE EMISSIONS SYSTEM RECALL ON THE 2021 ENCORE GX, BUT MINE IS A 2020. WHY WOULD A BRAND NEW, $38,000-CAR BE SO FRIGHTENINGLY UNRELIABLE? I TRADED IN TWO CARS AND SAVED MANY YEARS TO BUY THIS. I'M AFRAID TO EVEN DRIVE IT IN FOR SERVICE. MY DAD WAS A PATENTED ENGINEER. I MISS MY DAD.

NHTSA ID

11415944

Incident

May 5, 2021

Mileage

30 mi

STARTED HAVING TROUBLE LAST WEEK WITH THE FUEL GAUGE AND A CHECK ENGINE LIGHT. TOOK THE CAR IN TO HAVE IT SERVICED AND THEY FOUND THAT RODENTS HAD CHEWED THROUGH THE HARNESS LOCATED BY THE FUEL. COST $850 TO REPAIR WHICH WAS NOT COVERED UNDER WARRANTY. HAD THE CAR BACK TWO DAYS AND WENT TO USE THE CAR AND IT COMPLETELY STOPPED FUNCTIONING ONCE WE PULLED OUT INTO TRAFFIC. WE LIVE ON A HIGHLY TRACTOR TRAILER TRAVELED ROAD AND HAVING THE CAR JUST STOP WORKING COULD HAVE ENDED IN AN ACCIDENT IF A CAR WAS COMING FROM EITHER DIRECTION. MY SON WAS IN THE PASSENGER SEAT AND I AM INCREDIBLY UPSET THAT THEY COULD HAVE BEEN HURT. WE NEEDED TO CALL THE POLICE AND A TOW TRUCK WITH MY YOUNGEST SON IN THE CAR. RECEIVED A CALL FROM THE DEALERSHIP AFTER INSPECTION TO FIND OF THE SAME HARNESS HAS BEEN CHEWED THROUGH AGAIN. THE HARNESS APPARENTLY IS A SOY BASED PRODUCT. WE ARE BEING TOLD ONCE AGAIN THIS IS NOT COVERED UNDER WARRANTY AND MY BIGGER CONCERN IS HOW THIS IS GOING TO STOP HAPPENING. THIS DOES NOT SOUND LIKE AN OUTSIDE INFLUENCE BUT RATHER A MANUFACTURING DEFECT. USING A SOY BASED PRODUCT MAYBE CHEAPER TO MANUFACTURE AND BETTER FOR THE ENVIRONMENT BUT IT'S GOING TO MAKE THE CAR COMPLETELY UNSAFE FOR MY FAMILY TO BE IN. IF THE HARNESS IS GOING TO BE MADE OUT OF A SOY BASED PRODUCT AND I BELIEVE THAT THIS SHOULD BE SOMETHING NOW COVERED UNDER WARRANTY AND NOT EXPECTED FOR US TO PAY OUT OF POCKET FOR.

NHTSA ID

11403516

Incident

Mar 14, 2021

Mileage

38 mi

I WAS DRIVING HOME APPROX 6:00 PM AS I WAS STARTING ON L75 MY BUICK 2020GX WITH LESS THAN 300 MILES STARTED TO SPEED UP TO A VERY FAST MY BRAKES DID NOT SLOW ME DOWN THE CAR KEPT SPEEDING UP I WAS VERY SCARED WHEN THE CAR KEPT GOING FASTER NOW I AM SCARED TO DRIVE IT THERE WAS ALMOST A CRASH TRYING TO SLOW DOWN

NHTSA ID

11389607

Incident

Jan 23, 2021

Mileage

14 mi