The 2021 CT4-V with the 2.7L turbo four is a high-strung performance sedan with a factory-boosted engine that's showing alarming early-life failures related to piston ringland fractures and oil consumption. These aren't typical wear-out issues—they're design/metallurgy problems hitting well before 100k miles.
Catastrophic Piston/Ringland Failure (2.7L Turbo)
Occasional · high severity
Typical onset: 30,000-80,000 mi
Symptoms: Excessive oil consumption (1 qt per 1,000 mi or worse), Misfires, rough idle, check engine light (codes P0300-P0304), Blue smoke from exhaust on startup or acceleration, Knocking or rattling from engine under load
Fix: Ringland cracks or piston skirt failures require complete engine teardown. Short block replacement is typical—16-24 hours labor depending on shop efficiency and whether turbos come off. Some get warranty coverage if under 60k, but many owners are left holding the bag. GM has no official recall yet despite documented pattern failures.
Estimated cost: $8,000-14,000
Transmission Oil Cooler Line Leaks
Common · medium severity
Typical onset: 40,000-70,000 mi
Symptoms: Transmission fluid spots under vehicle (red/brown fluid), Low fluid warning on dashboard, Harsh or delayed shifts when fluid level drops, Visible seepage at cooler line fittings near radiator
Fix: The quick-connect fittings on the 10-speed's cooler lines crack or O-rings fail. Requires replacement of affected hard lines and sometimes the cooler itself. 2-3 hours labor. Not difficult but requires proper fluid flush and relearn procedure afterward.
Estimated cost: $600-1,200
Transmission Mount Failure
Occasional · medium severity
Typical onset: 50,000-90,000 mi
Symptoms: Clunking on hard acceleration or deceleration, Vibration through shifter or center console, Excessive drivetrain movement visible when revving in park, Transmission 'slapping' noise over bumps
Fix: The rear trans mount cracks at the rubber isolator or bracket. The 10-speed's torque spikes accelerate wear. Straightforward R&R—1.5-2 hours on a lift. OEM mount is recommended; aftermarket durability is hit-or-miss.
Estimated cost: $400-700
High-Pressure Fuel Pump Failure
Occasional · high severity
Typical onset: 50,000-90,000 mi
Symptoms: Long crank/hard start, especially when hot, Fuel rail pressure codes (P0087, P0191), Loss of power under wide-open throttle, Rough running, stumbling under boost
Fix: Direct-injection HP pump on the 2.7T fails prematurely—internal cam lobe wear or valve sticking. Pump is camshaft-driven and buried under intake plumbing. 4-5 hours labor to access and replace, plus fuel system depressurization and priming. Contamination from pump debris sometimes requires injector replacement too.
Estimated cost: $1,800-3,200
Turbocharger Wastegate Rattle and Boost Control Issues
Occasional · medium severity
Typical onset: 60,000-100,000 mi
Symptoms: Rattling from engine bay on cold start (wastegate actuator play), Overboost or underboost codes (P0234, P0299), Surging or hesitation during moderate acceleration, Limp mode if boost control faults repeatedly
Fix: Twin-scroll turbo's electronic wastegate actuator develops slop or the actuator rod binds. Sometimes cleaning and regreasing works short-term, but replacement is the reliable fix. Turbo R&R on this platform is 6-8 hours—tight engine bay, lots of heat shielding and intercooler plumbing in the way.
Estimated cost: $2,500-4,500
Infotainment System Freezes and CUE Black Screen
Common · low severity
Symptoms: Touchscreen unresponsive or stuck on Cadillac logo, Backup camera not displaying, Audio cuts out randomly, Climate controls locked out (controlled via screen)
Fix: CUE system software bugs or module overheating. Hard reset (pull fuse 11 in underhood box for 2 minutes) fixes it temporarily. Persistent cases need module reflash or replacement—1 hour labor plus programming time. GM issued TSBs for some cases but many still occur.
Estimated cost: $300-800
Owner tips
Check oil level every 500 miles religiously—the 2.7T drinks oil even when 'healthy,' and low oil accelerates the ringland failures
Change engine oil at 5k mile intervals with quality synthetic and OEM filter—extended intervals are a death sentence for this engine
Have a pre-purchase compression and leak-down test done if buying used; cylinder 2 and 3 fail first
Budget $200/year for frequent transmission fluid changes (every 30k)—the 10-speed runs hot and fluid degrades fast under performance use
Avoid extended idle times and short trips; these engines need full heat cycles to burn off fuel dilution
Great chassis and handling, but the 2.7T is a grenade with the pin half-pulled—buy only with comprehensive warranty or budget $10k for an eventual engine replacement.
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: AGM battery required for stop-start system; located in trunk
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Every control module on the 2020-2026 Cadillac CT4-V — 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.
⚠️ Power seat memory and heating/ventilation functions; two modules (driver/passenger)
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 2019-2020 Cadillac CT6, 2020-2021 CT4, CT5, and 2020-2022 Chevrolet Camaro vehicles equipped with a 10-speed transmission. The transmission may become damaged internally and cause the wheels to lock-up.
Consequence: Wheel lock-up while driving increases the risk of a crash.
Remedy: Dealers will install transmission control module monitoring software, free of charge. Owner notification letters were mailed April 7, 2025. Owners may contact Cadillac customer service at 1-800-333-4223 or Chevrolet customer service at 1-800-222-1020. GM's number for this recall is N242480630.
EXTERIOR LIGHTING:LIGHTING CONTROL MODULE:SOFTWARE · 22V903000
2022-12-08
General Motors, LLC (GM) is recalling certain 2020-2023 Cadillac CT4 and CT5; 2021-2023 Buick Envision; and 2022-2023 Cadillac Escalade and Escalade ESV, Chevrolet Silverado 1500, Suburban, Tahoe, GMC Sierra 1500, Yukon, and Yukon XL vehicles. The daytime running lights (DRLs) may not deactivate when the headlights are on. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 108, "Lamps, Reflective Devices, and Associated Equipment."
Consequence: DRLs that do not deactivate as intended may result in a glare, reducing visibility, and increasing the risk of a crash.
Remedy: The body control module software will be updated by a dealer, or through an over-the-air (OTA) update, free of charge. Owner notification letters were mailed January 23, 2023. Owners may contact GMC customer service at 1-888-988-7267, Chevrolet customer service at 1-800-222-1020, or Cadillac customer service at 1-800-458-8006. GM's number for this recall is N222386380. This recall expands previous recall number 22V-827.
AIR BAGS:SIDE/WINDOW:CURTAIN · 21V611000
2021-08-05
General Motors, LLC. (GM) is recalling certain 2020-2022 Cadillac CT4 and CT5 vehicles. The roof rail side-curtain air bags may not have been installed correctly, which could result in an improper air bag deployment during a crash.
Consequence: Air bags that do not deploy properly can increase the risk of injury in a crash.
Remedy: Dealers will inspect both left and right-side roof rail air bags and reinstall the air bags, as necessary, free of charge. Owner notification letters were mailed on August 30, 2021. Owners may contact Cadillac customer service at 1-800-458-8006. GM's number for this recall is N212342780.
AIR BAGS:SRS MALFUNCTION WARNING LAMP/LIGHT · 21V421000
2021-06-10
General Motors, LLC (GM) is recalling certain 2021 Buick Envision, Cadillac CT4, CT5, Escalade, Escalade ESV, Chevrolet Tahoe, Corvette, Suburban, GMC Yukon, Yukon XL vehicles. The communications gateway module incorrectly processes a loss of communication with the sensing diagnostic module (SDM), causing the air bag malfunction indicator light to inconsistently illuminate.
Consequence: The air bag malfunction indicator light may fail to warn the driver of a problem with the air bag, increasing the risk of injury.
Remedy: The communications gateway module software will be updated by a dealer, or through an over-the-air (OTA) update, free of charge. Owner notification letters were mailed on July 1, 2021. Owners may contact Buick customer service at 1-800-521-7300, Cadillac customer service at 1-800-458-8006, Chevrolet customer service at 1-800-222-1020, or GMC customer service at 1-800-462-8782. GM's number for this recall is N212338110.
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 2021 Cadillac CT4-V 2.7L Turbo I4 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.