GM 2.7L L3B Turbo Engine: Specs, Problems, and Reliability. The GM L3B engine is the all-new 2.7-liter four-cylinder turbocharged gasoline engine released in the 2025 Chevrolet Silverado 1500 and 2025 GMC Sierra 1500. This engine was designed specifically for use in full-size pickup trucks, and incidentally, it is the first 4-cylinder ever used for GM’s full-size pickups. The L3B engine is produced in the USA at Spring Hill Manufacturing, General Motors factory in Spring Hill, Tennessee.
The 2.7 Turbo L3B has a deep-skirt, freely ribbed die-cast aluminum (380 T5) cylinder block with iron liners. It includes a long piston stroke of 4.01 inches (102 mm) that provides the strong low-end torque but on the contrary, this boosted vibrations. To bring smoothness back, the engine block was equipped with a dual balance shaft mechanism. The engine block also has a forged steel crankshaft with hardened journals and tri-metal bearings.
The crankshaft is offset from the cylinder bore centerline. Offset position reduces friction from piston side-loading. Pistons themselves are lightweight aluminum with fully machined crowns and cast iron ring carriers. Pistons are additionally cooled by oil spray squirters. The engine is equipped with a continuously variable-output oil pump. The oil pump, along with balance shafts, is supported by a bolt-on aluminum lower crankcase extension. All-time low side is sealed by a nylon-reinforced plastic oil pan.
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GM 2.7L L3B Turbo Engine: Specs, Problems, and Reliability
In addition to the engine block, there is an aluminum alloy (356 T5) 16-valve cylinder head with high-tumble combustion chambers and dual-overhead camshafts. The cylinder head uses copper-alloy exhaust valve guides for exhaust valves to improve heat transfer and valve cooling. The intake and exhaust camshafts are driven by an 8 mm roller timing chain. The 2.7 L L3B valvetrain includes GM’s Sliding Cam Valve Lift System (SCS), which has three distinct operating modes: High Lift, Low Lift, and AFM (Active Fuel Management) mode. During High Lift mode, all cylinders are active, plus all valves open to their maximum lift. Low Lift mode (3 mm less) reduces the duration of the intake valve available to conserve fuel under medium load conditions. In AFM mode, cylinders 2 and 3 are deactivated, reducing fuel consumption in light load conditions. The intake and exhaust sides also come with continuously variable valve timing management.
The L3B engine includes a high-pressure direct fuel injection system. The high-pressure fuel pump produces up to 3000 psi (20 MPa) of fuel pressure for side-mounted direct injectors that able to provide around three injection events per combustion cycle. The direct injection cooperates with a high-energy coil-on-plug electronically controlled ignition system – Spark Ignited Direct Injection (SIDI). Like most modern turbocharged engines, the 2.7 L3B utilizes a cylinder head design with an integrated and water-cooled exhaust manifold to shorten the engine warm-up period (for passing emissions tests) and prolong the turbocharger life keeping it “cool” during high loads.
GM 2.7L L3B Turbo Engine: Specs
| Manufacturer | Spring Hill Manufacturing plant, Spring Hill, Tennessee, the USA |
| Production years | 2018-present |
| Cylinder block material | Aluminum |
| Cylinder head material | Aluminum |
| Fuel type | Gasoline |
| Fuel system | Direct Injection |
| Configuration | Inline |
| Number of cylinders | 4 |
| Valves per cylinder | 4 |
| Valvetrain layout | DOHC |
| Bore, mm | 92.2 mm (3.63 in) |
| Stroke, mm | 102.0 mm (4.02 in) |
| Displacement, cc | 2,727 cc (166.4 cu in) |
| Type of internal combustion engine | Four-stroke, turbocharged |
| Compression Ratio | 10.0:1 |
| Power, hp | 310-325 hp (231-242 kW)/ 5,500-5,600 |
| Torque, lb ft | 348-380 lb ft (472-515 Nm)/ 1,500-4,000 |
| Engine weight | – |
| Firing order | 1-3-4-2 |
| Engine oil weight | SAE 5W-30 full synthetic motor oil |
| Engine oil capacity, liter | 5.7 l (6.0 qt) – with oil filter |
| Oil change interval, mile | 10,000 (15,000 km) / 12 months |
| Applications | Chevrolet Silverado 1500, Chevrolet Colorado, GMC Sierra 1500, GMC Canyon, Cadillac CT4 Premium Luxury, Cadillac CT4-V |
The engine uses the newest BorgWarner’s single dual-volute turbocharger that supplies 22 psi (1.5 bar) of max boost. This turbocharger uses an electrically actuated wastegate. The pressurized air undergoes an air-to-air intercooler that lowers its temperature by about 130 degrees F (74 C). Another unique feature of this new engine is GM’s active thermal management cooling system. This system contains ECM controlled electric water pump and a 3-way rotary valve. An electric water pump supplies coolant flow to heat the passenger compartment, to cool the engine and transmission.
The new GM L3B 2.7 L engine was designed with a target to replace the 4.3 L V6 engine and engineers coped with the task successfully. It produces 9% more horsepower and 14% more torque, weighs 80 lbs (36 kg) less, and consumes 13% less fuel with better emissions than its predecessor. Matched up with a major competitor, Ford’s V6 2.7-liter EcoBoost engine (325 hp and 400 pound-feet of torque), the GM 2.7-liter 4 banger loses performance battle producing 310 hp and only 348 pound-feet of torque.
2.7 L3B Turbo Engine Problems and Reliability
Is the GM 2.7 L3B a reliable and good engine? Well, it is well packed with all sorts of technology to boost fuel efficiency and performance. Many things may go wrong, but GM claimed the new engine successfully accumulated an equivalent of over one million miles of over-the-road durability validation testing. Only real-life and time will tell how GM’s new 2.7-liter turbo engine is reliable.
But also for now, be certain that the engine is more vulnerable to the quality and condition of the engine oil, like all modern turbocharged and direct-injected engines are. A lack of maintenance will destroy this engine very fast. The fuel delivery system has a controversial decision to use direct injection only, while almost all direct-injected-only engines from other manufacturers were revised and received combined direct and port injection. Combined fuel injection prolongs the life of the cylinder wall surface and prevents a carbon buildup on intake valves and walls inside intake ports.
