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

GM/Chevy 6.2L EcoTec3 Info

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 6.2L V8 engine is part of the Gen5 small-bock engine family, also known as EcoTec3. The L86 version debuted 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 2019. Both engines are basically identical, but the newest L87 variant uses Dynamic Fuel Management instead of the L86's Active Fuel Management. The 6.2L EcoTec3 was also available in Chevy sports cars and higher-performance Cadillac models (LT1, LT2, and supercharged LT4 and LT5). But in this article, let's take an in-depth look at the design of L86 and L87 truck engines, their common problems, and reliability.

GM 6.2 EcoTec3 Engine Overview

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 is the same across all Gen5 small block engines. The rotating assembly features a forged-steel crankshaft, I-beam powder-metal connecting rods (6.098 in long), and cast aluminum domed pistons optimized for direct injection. Like the 5.3L V8 L83, this engine also had piston oil jets/squirters, a variable-displacement oil pump (wet sump), and nodular main bearing caps. All of these components work well for improving engine efficiency and extending long-term engine durability.

The 6.2L EcoTec3 engine features a pushrod OHV design and a single camshaft sitting inside the engine block. Aluminum cylinder heads come with two valves per cylinder (16 valves total). Pushrods activate intake and exhaust valves via low-friction roller-pivot rocker arms. Furthermore, the valvetrain includes hydraulic roller-lifters, and no valve clearance adjustment is required. Instead of the already conventional VVT system found in 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 5.3L motor, the L86 6.2L version has larger valves. The intake valve diameter is 2.126 in. (54 mm); the exhaust valve diameter is 1.590 in. (40.4 mm). Pushrods are the same 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.

In addition to a tank-located low-pressure fuel pump, the 6.2L L86/L87 engine has a high-pressure fuel pump mounted in the valley between cylinder heads. The camshaft drives the HP pump with an additional cam called a trilobe. This pump pressurizes fuel up to 15 MPa (150 bar) and sends it to direct injectors. And then, 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 features individual coils near plugs 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.

Active Fuel Management Technology

The 6.2L L86 version features 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 6.2L L87 version switched to the latest Dynamic Fuel Management technology (DFM), which alternates between any of 17 different firing orders based on demand, calculated every 125 milliseconds. Both engines can run on gasoline or gasoline-ethanol blends of up to 85% ethanol (E85). Chevy/GMC trucks and SUVs with the 6.2L EcoTec3 motor are flex-fuel capable.

Engine Specs

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

Like the entire EcoTec3 family, the 6.2-liter version was developed to offer a much more fuel-efficient and environmentally friendly V8 engine compared to the previous Vortec versions. Unfortunately, these two things are rarely combined with durability. The 6.2L EcoTec3 truck engine is not an exception.

GM 6.2L L86/L87 Common Problems

Here is the list of the most common Chevy/GMC 6.3L V8 EcoTec3 engine problems:

• Carbon buildup on the intake valves
• Lifters collapse and bent pushrods caused by the AFM system
• Direct injection related problems (HP pump and direct injectors failure)
• Unreliable intake manifold gaskets
• Broken exhaust manifold bolts

While the last three common issues are not a big thing and a carbon build-up is the nature of almost every other direct-injected engine, stuck lifters and bent pushrods really hurt the reliability score of the 6.2L L86 motor (more information in the 5.3L EcoTec3 engine review). And this is doubly painful because this problem usually occurs on low-mileage, almost new trucks. Although the warranty may cover all fixes, the potential issue in the future undermines your confidence in your vehicle. We believe the newest 6.2L L87 version with the Dynamic Fuel Management system is the better choice and hope that it is less prone to lifter failures.

GM 6.2L L86/L87 Reliability Summary

Drawing the line, is the 6.2-liter EcoTec3 a good, reliable engine? Yes, it's not unreliable by any means. Of course, 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 the recommended oil, and keep your vehicle well maintained. With regular service intervals and proper maintenance, Chevy/GMC 6.2 L86/L87 engines can last over 250,000 miles.