The 2019 GMC Acadia represents the second generation of this crossover, with the 3.6L V6 being the volume seller. While it's a capable family hauler, this platform has serious documented issues with transmission oil cooling and catastrophic engine failures on V6 models that can turn an affordable used SUV into a financial nightmare.
Transmission Oil Cooler Failure Leading to Transmission Contamination
Common · high severity
Typical onset: 40,000-80,000 mi
Symptoms: Pink or milky transmission fluid indicating coolant cross-contamination, Transmission slipping or harsh shifts after cooler fails, Check engine light with transmission-related codes, Coolant level drops with no visible external leaks
Fix: The internal transmission oil cooler in the radiator fails and allows coolant to mix with ATF, destroying the transmission. Requires new radiator (2-3 hrs) and often full transmission replacement or rebuild (8-12 hrs) if contamination went undetected. Flushing alone rarely saves a contaminated trans.
Estimated cost: $3,500-7,500
3.6L V6 Catastrophic Engine Failure (Piston Ring Land / Bearing Failure)
Occasional · high severity
Typical onset: 60,000-120,000 mi
Symptoms: Excessive oil consumption (quart every 500-1000 miles), Metal shavings or glitter in oil during changes, Knocking or ticking noise from lower engine, especially cold starts, Sudden loss of oil pressure leading to complete seizure, White or blue smoke from exhaust
Fix: The 3.6L V6 in this generation has documented issues with piston ring land fractures and bearing failures, often requiring complete engine replacement or rebuild with pistons, rings, bearings, and sometimes crankshaft. Short block replacement is 18-24 hrs, full rebuild 25-30 hrs. Some owners report failures even with religious oil changes.
Estimated cost: $6,500-11,000
Transmission Mount Failure
Common · medium severity
Typical onset: 50,000-90,000 mi
Symptoms: Clunking when shifting from park to drive or reverse, Vibration felt through floor and steering wheel at idle, Excessive drivetrain movement visible when engine revved in park, Transmission appears to 'drop' into gear harshly
Fix: The upper transmission mount deteriorates prematurely, allowing excessive powertrain movement. Replacement requires supporting the transmission and removing the through-bolt (2-3 hrs). Often done alongside engine mounts if multiple are worn.
Estimated cost: $350-600
Fuel System Contamination / Clogged Fuel Filter
Occasional · medium severity
Symptoms: Hard starting or extended cranking, especially after sitting, Rough idle and misfires under load, Loss of power during acceleration, Check engine light with fuel trim or misfire codes
Fix: Some units have experienced fuel system contamination from tank debris or defective in-tank components. The fuel filter is part of the in-tank pump module. Diagnosis requires fuel pressure testing (0.5 hrs), replacement of pump module is 2-3 hrs including tank drop. Sometimes requires fuel injector cleaning or replacement if contamination reached them.
Estimated cost: $800-1,800
EVAP Purge Valve and Canister Failures
Occasional · low severity
Typical onset: 40,000-80,000 mi
Symptoms: Check engine light with P0496 or P0442 EVAP codes, Fuel smell around vehicle, especially after fill-up, Rough idle or stalling immediately after refueling, Difficulty filling fuel tank (pump clicks off repeatedly)
Fix: The EVAP purge valve sticks open or the charcoal canister becomes saturated/damaged. Purge valve replacement is 1-1.5 hrs. If canister is damaged (often from topping off tank), replacement requires removing rear fascia and accessing components above fuel tank (3-4 hrs).
Estimated cost: $250-900
A/C Condenser Damage from Road Debris
Common · medium severity
Symptoms: A/C blows warm air, Visible refrigerant oil staining on condenser front, A/C system won't hold charge, Green or oily residue visible through grille
Fix: The A/C condenser sits directly behind the lower grille with minimal protection, making it vulnerable to rock damage. Requires evacuation of system, removal of front bumper cover, condenser replacement, drier replacement, vacuum and recharge (4-5 hrs total).
Estimated cost: $800-1,400
Owner tips
Check transmission fluid color religiously every 5,000 miles—pink or milky means cooler failure is happening NOW and can save the trans if caught early
On 3.6L V6 models, monitor oil consumption closely and send used oil sample to lab by 60k miles to check for bearing material—early warning of catastrophic failure
Change transmission fluid every 50,000 miles with AC Delco fluid regardless of 'lifetime fill' claims—helps catch cooler contamination and extends trans life
Inspect condenser through grille regularly and consider aftermarket condenser guard if you drive gravel roads
Never top off fuel tank past first click—overfilling damages EVAP canister and causes expensive repairs
Hard pass on the 3.6L V6 unless you can verify oil consumption history and transmission cooler has been preemptively replaced—too many grenaded engines and transmissions to recommend as a used buy.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.
Fitment notes: Located under hood on driver side; AGM battery required for vehicles with start-stop technology
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Every control module on the 2018-2022 GMC Acadia — where it lives, replacement time, and what it takes to program a replacement. Modules marked dealer / factory tool won't work after a part swap alone — budget for programming.
📍 Engine compartment, mounted to ABS hydraulic unit on left front frame rail near master cylinder
🔧 GM SPS2 via MDI/MDI2
⚠️ Integrated with hydraulic unit. Brake bleeding required after replacement. Controls ABS, traction control, StabiliTrak.
Body Control Module (BCM)1.5 hr R&Rsecurity gateway +1.0 hr▸ programming details
📍 Behind left side of instrument panel, above fuse block
🔧 GM SPS2 via MDI/MDI2
⚠️ Controls lighting, door locks, wipers, horn, power windows. Extensive configuration required for all body options.
Transfer Case Control Module (TCCM)1.5 hr R&Rdealer / factory tool +0.4 hrAWD models (all Acadias are AWD or FWD; AWD has active transfer case)▸ programming details
📍 Mounted to transfer case on left side
🔧 GM SPS2 via MDI/MDI2
⚠️ Controls AWD engagement and torque distribution. Relearn procedure required.
📍 Engine compartment, rear of engine valley under intake manifold (3.6L V6); right side of engine block near firewall (2.5L I4); left front of engine near battery (2.0L turbo)
Headlamp Control Module (HCM)0.6 hr R&Raftermarket tool +0.3 hrwith automatic headlamps or LED/HID headlamps▸ programming details
📍 Behind left headlamp assembly in engine compartment
🔧 Autel or GM SPS2
⚠️ Controls adaptive lighting and auto high-beam functions when equipped.
Rear Camera Module (RCM)0.5 hr R&Rrelearn only +0.2 hr▸ programming details
📍 Integrated with rear liftgate handle assembly
🔧 GM SPS2 or Autel
⚠️ Standard equipment. Simple relearn typically sufficient unless part of Surround Vision system.
Aftermarket tool coverage varies by software version and vehicle build — treat "aftermarket tool" rows as "usually possible" and verify against your tool maker's coverage list before promising a customer. Spot a wrong location or hour? Tell us — corrections ship fast here.
General Motors LLC (GM) is recalling certain 2020 Buick Enclave, Cadillac XT4, XT5, Escalade, Escalade ESV, Chevrolet Suburban, Tahoe, Traverse, GMC Yukon, Yukon XL, 2018-2021 Chevrolet Express, GMC Savana, 2019-2020 Chevrolet Blazer, Silverado 1500, GMC Acadia, Sierra 1500, and certain Continental tires sold to the aftermarket for various model year 2018-2021 vehicles. The affected tires were cured for too long during production.
Consequence: Over cured tires may develop a break in the sidewall resulting in sudden air loss or a belt edge separation which could lead to a tread/belt loss. Either condition can cause a loss of vehicle control, increasing the risk of a crash.
Remedy: GM will notify owners, and dealers will inspect the tires, replacing them as necessary, free of charge. The recall began March 22, 2021. Owners may contact GMC customer service at 1-888-988-7267, Buick customer service at 1-866-608-8080, Chevrolet customer service at 1-800-222-1020 or Cadillac customer service at 1-800-458-8006. GM's number for this recall is N212329050.
POWER TRAIN:AUTOMATIC TRANSMISSION · 20V668000
2020-10-29
General Motors LLC (GM) is recalling certain 2018-2019 Chevrolet Cruze and Buick LaCrosse, 2018-2020 Chevrolet Equinox, Chevrolet Traverse and GMC Terrain, 2018 Chevrolet Malibu, 2019-2020 Buick Encore, Buick Enclave, Cadillac XT4, Chevrolet Blazer and GMC Acadia, and 2020 Cadillac XT6 vehicles. The start/stop accumulator endcap may have missing bolts.
Consequence: Missing bolts on the start-stop accumulator endcap could result in a transmission oil leak and may progress to a loss of propulsion, increasing the risk of a crash. A transmission fluid leak in the presence of an ignition source may increase the risk of fire.
Remedy: GM will notify owners, and dealers will inspect the start-stop transmission accumulator and replace it if any bolts are missing, free of charge. The recall began December 15, 2020. Owners may contact GMC customer service at 1-888-988-7267, Buick Customer service at 1-866-608-8080, Chevrolet customer service at 1-800-222-1020 or Cadillac customer service at 1-800-458-8006. GM's number for this recall is N202313440.
Size-standard part numbers — verify your connector type before buying. Rear blades are model-specific; check the package's vehicle list.
Fuel economy figures are EPA data via fueleconomy.gov (median across matching trims). Performance figures are compiled estimates for the 2019 GMC Acadia 3.6L V6 and can vary by trim.
🔧 Database maintained under the daily editorial review of Chris Hackleman · Master Technician · 20+ years and Jeff Moore · Master Lexus & Toyota Mechanic · 20+ years.