This service bulletin provides information on replacing the intake manifold when the engine is replaced after severe internal engine damage.
full bulletin at NHTSA ↗2020 Buick Enclave engine problems
moderate Owners of the 2020 Buick Enclave have filed 13 NHTSA complaints about the engine at roughly $3,100 to repair (U.S. federal records, as of July 2026). Source: NHTSA Office of Defects Investigation. See engine across all vehicles →
Complaints
13
Recalls
0
Avg fix
$3,100
| Model year | engine complaints |
|---|---|
| 2016 Enclave | 3 |
| 2018 Enclave | 7 |
| 2019 Enclave | 4 |
| 2020 Enclave (this page) | 13 |
What stands out
Engine accounts for 24% of all owner complaints filed against this vehicle, across 4 categories tracked.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering engine on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
The service bulletin advises the tech of a normal transmission shift condition and the delay in throttle response when the throttle plate is opened rapidly and advises the customer that it is normal for the delay.
full bulletin at NHTSA ↗This service bulletin provides information to dealership personnel for new vehicles with less than 1,000 miles that may not pass California smog inspection or smog inspection in other states.
full bulletin at NHTSA ↗This warranty administration bulletin provides policy information on vehicles outside of a California Emissions State who move to and register their vehicle in a California Emission State may be entitled to the 7 year, 70,000-mile Emission Select State Component Limited Warranty.
full bulletin at NHTSA ↗This service bulletin provides a repair procedure to correct a customer concern of a Malfunction Indicator Lamp (MIL) Illuminated - DTC P3055 Set.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
Owners of 2020 Buick Enclaves describe two categories of defects. The first involves internal oil seepage from the engine block, usually a rear main seal failure that triggers low-oil warnings within weeks of a full oil change. One owner's mechanic confirmed oil seeping from the engine despite a clean oil filter and drain plug; a Buick dealership recommended complete engine replacement plus rear main seal repair and oil pan resealing.
The second, more prevalent issue is cracking or separation of the front exhaust pipe mounting bracket. Eight owners report this failure, which creates a hole in the exhaust pipe and allows exhaust fumes and carbon monoxide to enter the cabin through the HVAC system. Symptoms include ticking noises under the hood, strong exhaust smell, and (in one case) months of undetected carbon monoxide exposure. One owner was quoted $1,000 for repair. Notably, owners cite that GM issued special coverage and recalls (N212356540, N222385510) for identical defects on 2019 and 2021 Enclave and Traverse models, but extended no coverage to the 2020 model year.
A third group reports sudden acceleration, jerking, and vibration when shifting into Drive, accompanied by illuminated check engine lights. One diagnosis identified a clogged catalytic converter and failed brake and transmission modules, though the vehicle cleared the fault after several minutes. Owners express concern these issues pose safety risks.
Failure modes owners describe
Rear Main Seal Failure / Internal Oil Leakage
Engine oil seeps from the engine block, specifically from a rear main seal failure, despite oil filter and drain plug showing no visible leaks. Owners report repeated low-oil warnings within weeks of an oil change.
When: Recurring within months of ownership; one case noted 52,580 miles on related vehicle
Symptoms owners cite: Repeated low-oil warning lights shortly after full oil change; Oil seeping from engine block interior; No external leaks at filter or drain plug
Repairs/costs cited: Complete engine replacement, rear main seal repair, oil pan resealing required per dealer diagnosis
Sudden Acceleration and Jerking
Vehicle exhibits sudden acceleration, jerking, and vibration when shifting into Drive, accompanied by illuminated check engine light and other warning lights. Failures are intermittent but recurring.
When: Mileage unknown; occurs within short distances of each other
Symptoms owners cite: Vehicle jerks and vibrates upon accelerating from park/reverse; Check engine light and multiple unknown warning lights illuminate; Intermittent—vehicle functions normally for a time, then failure recurs; Failure clears after several minutes without repair
Repairs/costs cited: Private dealer diagnosed clogged catalytic converter, failed electronic brake control module, and failed transmission module; no repairs completed
Front Exhaust Bracket Cracking / Separation
The mounting bracket securing the front exhaust pipe to the frame cracks or separates, creating a hole in the exhaust pipe and allowing exhaust fumes and carbon monoxide to enter the cabin via ventilation. This is the most common failure mode across multiple model years.
When: Mileage varies; one reported at 52,580 miles; some owners unaware of when separation occurred
Symptoms owners cite: Abnormal ticking sound from engine bay; Hole or crack in front exhaust pipe; Strong exhaust smell inside cabin (via AC vents); Carbon monoxide detected in passenger compartment; Loud noise from exhaust area
Repairs/costs cited: Dealer quotes $1,000+ for bracket and pipe replacement; owners report this is identical to defects on 2019 and 2021 models
Recalls/TSBs owners mention: GM issued recall N222385510 for 2021 Chevrolet Traverse only; special coverage adjustments N212356540, N252503850, N242445280, and N222385510 issued for 2019 and 2021 Buick Enclaves and Chevy Traverses but not extended to 2020 model
Flex Pipe Bracket Cracking / Exhaust Pipe Damage
The flex pipe bracket cracks, causing the intermediate exhaust pipe to crack or fail. The defect allows cracked exhaust to enter the cabin.
When: Mileage unknown at report; documented defect in 2018–2019 and 2021–2023 model years
Symptoms owners cite: Abnormal ticking from engine bay; Cracked passenger-side flex pipe bracket; Damage to catalytic converter; Exhaust fumes entering passenger cabin
Repairs/costs cited: Flex pipe and catalytic converter replacement required; not completed in reported case
Recalls/TSBs owners mention: Manufacturer informed contact no recall exists for their VIN; related recalls and special coverage exist for other model years
Synthesized from 13 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 6 most recent
The mounting bracket on the front exhaust pipe separates from the pipe. This issue has been identified on 2019 and 2021 models and special coverage adjustment N212356540 Front Exhaust Pipe has been issued. The same exact defect has occured to my 2020 model Enclave.
2020 Buick Enclave mounting bracket separated from the front exhaust pipe which caused a hole to appear in the exhaust pipe. This is a known issue for 2019, 2021, and 2022 Buick Enclaves. No warning light The exhaust fumes along with Carbon Monoxide were coming through my ac vents for several months. There is no indication on when the mounting bracket separated.
Front exhaust flex pipes had to be replaced. It’s a common problem and a recall exists for the prior year.
The vehicle's exhaust intermediate pipe mount has broken has caused damage in the intermediate pipe requiring both the be replaced. The cracked exhaust allows exhaust fumes to enter the passenger compartment. A recall (N222385510) for 2021 Chevrolet Traverse has been made however is addressing this on only the 2021 models, even though the same issue is applicable to other models. On the this…
The front exhaust pipe bracket has broken. Upon investigation, this is an ongoing issue for 2018-2019, and 2021-2023 Chevy Traverse and Buick Enclave models, but NOT 2020. All of the models use the exhaust system and same bracket, and it should be included as a special coverage. In fact, the attached picture of my vehicle will show that it is an identical break to those pictures used in the…
Front exhaust pipe separated from its mounting bracket causing a consistent rattle. This condition is exactly as described in "N222385510 - Special Coverage Front Exhaust Pipe", released in May 2023. Exhaust components in this vehicle are materially the same as the covered 2021 vehicles and thus this vehicle should be similarly covered. Issue has been confirmed by a dealer and is available for…
Had engine trouble with your 2020 Buick Enclave?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the engine problem on the 2020 Buick Enclave?
It's a documented issue but not catastrophic. 13 complaints have been filed. Repairs average $3,100 and most owners catch it before it causes a breakdown.
At what mileage does the engine typically fail?
Based on the 13 complaints filed, engine issues most often appear around 52,580 miles. Some report problems earlier; some make it well past 150,000 with no symptoms. Maintenance habits matter — vehicles that received timely fluid services and were not regularly overworked tend to last longer.
What does it cost to fix?
Independent shops typically charge around $3,100 for engine repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to engine?
No active recalls currently cover engine issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2020/Buick/Enclave.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.