GM 6.2L EcoTec3 L86/L87 Engine: Specs, Problems, Reliability

GM 6.2L EcoTec3 L86/L87 Engine: Specs, Problems, Reliability. The L86/L87 is an all-aluminum 6.2-liter naturally-aspirated and direct-injected gasoline V8 engine developed by GM for use in pickup trucks and SUVs (Chevrolet Silverado, GMC Sierra, Cadillac Escalade, GMC Yukon Denali, and more). This 6.2 L V8 engine is a part of the Gen5 small bock engine family also known as EcoTec3. The L86 version come out in 2014 and replaced its predecessor out of Vortec truck engines – the L92 6.2-liter motor. The successor to the L86, the L87 version came out in 2025. Both engines are basically identical, but the newest L87 variant uses Dynamic Fuel Management instead of the L86’s Active Fuel Management.

GM 6.2L EcoTec3 L86/L87 Engine: Specs, Problems, Reliability

The 6.2 L EcoTec3 was also available in Chevy sports cars and higher performance Cadillac models – LT1, LT2, and supercharged LT4 and LT5 versions. In this article, let’s take an in-depth look at the design of L86/L87 truck engines, their common problems, and reliability.

As was said, the GM 6.2 L86 and L87 are all aluminum engines. They use a 90-degree aluminum cylinder block with cast-in iron cylinder liners. By the way, the engine block is similar to the 5.3-liter EcoTec3 version. The 6.2-liter engine gets its displacement from the increased bore of 103.25 mm (4.065 in). The 92 mm (3.622 in) stroke coincides across all Gen5 small block engines. The rotating assembly includes a forged-steel crankshaft, I-beam powder-metal connecting rods (6.098 in long), and cast aluminum domed pistons optimized for direct injection. Like 5.3 L V8 L83, this engine also got piston oil jets/squirters, variable-displacement oil pump (wet sump), and nodular main bearing caps. All of these components work both well for improving engine efficiency and extending long-term engine durability.

GM 6.2L EcoTec3 L86/L87 Engine: Specs, Problems, Reliability

GM 6.2L EcoTec3 L86/L87 Engine: Specs, Problems, Reliability

The 6.2 L EcoTec3 engine includes a pushrod OHV design and a single camshaft sitting inside the engine block. Aluminum cylinder heads possess two valves per cylinder (16 valves total). Pushrods activate intake and exhaust valves via low-friction roller-pivot rocker arms. The valvetrain includes hydraulic roller-lifters, and no valve clearance adjustment is required. As opposed to the already traditional VVT system found of most modern engines with DOHC, the L86/L87 uses a dual-equal camshaft phasing system that adjusts timing at the same rate for both intake and exhaust valves.

Compared to the 5.3 L motor, the L86 6.2 L version has larger valves. The intake valve diameter is 2.126 in. (54 mm); the exhaust valve diameter – 1.590 in. (40.4 mm). Pushrods coincide 7.85 inch-long with 0.342 in. (8.7 mm) outside diameter. The camshaft has the following specs: 200/207 duration (intake/exhaust), 0.551 in./ 0.524 in. valve lift for intake and exhaust, respectively.

GM 6.2L EcoTec3 L86/L87 Engine: Specs

Manufacturer GM Tonawanda engine plant in New York
Production years 2014-present
Cylinder block material Aluminum
Cylinder head material Aluminum
Fuel type Gasoline
Fuel system Direct Injection
Configuration V
Number of cylinders 8
Valves per cylinder 2
Valvetrain layout OHV
Bore, mm 103.25 mm (4.065 in)
Stroke, mm 92.0 mm (3.62 in)
Displacement, cc 6,162 cc (376 cu in)
Type of internal combustion engine Four-stroke, naturally aspirated
Compression Ratio 11.5:1
Power, hp 420 hp (313 kW)/ 5,600
Torque, lb ft 460 lb-ft (624 Nm)/ 4,100
Engine weight
Firing order 1-8-7-2-6-5-4-3
Engine oil weight SAE 0W-20
Engine oil capacity, liter 8.0 l (8.45 qt) – with oil filter
Oil change interval, mile 7,500 (12,000 km)/12 months
Applications Chevrolet Silverado, Chevrolet Suburban, GMC Sierra, GMC Yukon XL, GMC Yukon Denali/Denali XL, Cadillac Escalade/Escalade ESV
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Along with a tank-located low-pressure fuel pump, the 6.2 L L86/L87 engine has an additional high-pressure fuel pump mounted in the valley between cylinder heads. The camshaft drives the HP pump by an additional cam called a trilobe. This pump pressurizes fuel approximately 15Mpa (150 bar) and sends it to direct injectors. And after that, direct fuel injection technology precisely shoots fuel directly into the combustion chamber.

Engineers also placed platinum-tipped spark plugs closer to the center of the combustion chamber to further improve the combustion process. The electronically controlled ignition system Quick Sync 58X also includes individual coils near plugs design and low-resistance spark plug wires. The truck-style intake manifold is made of composite material. It’s fitted with a drive-by-wire electronic throttle body with a 4-bolt 87 mm throttle valve. The engine also got the newest E92 ECU, which manages all electronic systems and engine data.

The 6.2 L L86 version includes GM’s Active Fuel Management (AFM) technology. The AFM is a cylinder deactivation technology that alternates between V-4 and V-8 modes depending on load conditions. It is an oil-operated system that deactivates the lifters on selected cylinders closing the valves for those cylinders. The newer 6.2 L L87 version switched to the current Dynamic Fuel Management technology (DFM) that alternates between any of 17 different firing orders based upon demand calculated every 125 milliseconds. Both engines can run on gasoline or gasoline-ethanol blends of around 85% ethanol (E85). Chevy/GMC trucks and SUVs with the 6.2 L EcoTec3 motor are flex-fuel capable.

GM 6.2 L L86/L87 V8 EcoTec3 Engine Problems and Reliability

Like the entire EcoTec3 family, the 6.2-liter version was developed to offer a more fuel-efficient and ecologically friendly big V8 engine compared to the previous Vortec versions. These two things are rarely combined with durability. The 6.2 L EcoTec3 truck engine is not an exception. Here is the list of the absolute most common Chevy/GMC 6.3 L V8 EcoTec3 engine problems:

  • Carbon build-up on the intake valves
  • Lifters collapse and bent pushrods triggered by AFM system
  • Direct injection related problems (HP pump and direct injectors failure).
  • Unreliable intake manifold gaskets.
  • Broken exhaust manifold bolts.
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Even though the last three common issues are not a big thing and a carbon build-up is the nature of almost intermittent direct-injected engine, stuck lifters and bent pushrods really hurt the reliability score of the 6.2 L L86 motor (more information in the 5.3 L EcoTec3 engine review). And this is doubly painful because this problem usually occurs on low-mileage, almost new trucks. The warranty may cover all fixes, the potential issue in the future undermines your confidence in your vehicle. Our team believe the newest 6.2 L L87 version with the Dynamic Fuel Management system is the better choice and hope that it is less prone to lifter failures.

Drawing the line, is the 6.2-liter EcoTec3 a good trusted engine? Yes, it’s not unreliable whatsoever. Obviously, the engine is not perfect, and problems will occur, especially with age. But it also does not mean that the common problems above occur on every 6.2 EcoTec3 V8. To extend the engine life, use premium 93-octane gasoline, pour only recommended oil, and keep your vehicle well preserved. With frequent service intervals and proper maintenance, Chevy/GMC 6.2 L86/L87 engines can last over 250,000 miles.