GM 6.2L L92/L9H/L94 Engine Specs, Problems, Reliability, Info

6.2L LS-based Gen4 V8 Engine Info

The Vortec 6200 L92 and L94 engine is an all-aluminum, naturally-aspirated 6.2-liter Gen4 V8 engine (LS Family) produced from 2006 to 2014 and used in luxury pickups and SUVs. This is a truck version of the high-performance LS3 and L99 engines, which make over 400 horsepower. It debuted in the 2007 Cadillac Escalade as the L92 model, rated at 403 horsepower and 417 pound-feet of torque. Through the years, these 6.2-liter engines (L92, L9H or L94) have been widely used in many popular GM vehicles, including the Tahoe, Sierra 1500, Yukon, Yukon XL and Hummer H2.

6.2L Gen4 Engine Overview

L92 Engine

The L92 is a motor from 2006 to 2008, also known as the Vortec 6200. It is built around a lightweight aluminum cylinder block (the casting number is the same as that of the LS3 and L99). This block came with a cast iron crankshaft, 6.098 inch-long powdered metal I-beam connecting rods, and flat-top cast aluminum pistons. On top of the block, there are aluminum 8-valve cylinder heads with rectangle intake ports and D-shaped exhaust ports. The engine features a pushrod OHV design with a single camshaft sitting in the valley. The valvetrain came with hydraulic roller lifters, die-cast roller rocker arms, and 7.385-inch long pushrods. This engine also got a Variable Valve Timing system (VVT). The stock camshaft specs: 198/209 duration (intake/exhaust), 0.500 in./0.500 in. valve lift (intake/exhaust). Intake valve diameter is 2.165 inches (50.8 mm). Exhaust valve diameter: 1.590 inches (40.4 mm). Both the intake and exhaust valves are made of steel with solid stems.

The 6.2L L92 is equipped with a conventional electronic port fuel injection system and electronic coil-near-plug 58X ignition. The intake manifold is made of plastic material, and it came with 4-bolt, 87 mm electronic throttle body (drive-by-wire control). En engine control module is GM E38 PCM. While the L92 version did not utilize AFM technology, all engines built prior to April 1, 2006 had AFM components inside, but these were left unused, because the mode was not enabled in the PCM. Later L92 engines, so-called "2nd Design", did not have AFM hardware at all. Also, all 6.2L L92 engines are not flex-fuel capable.

L9H Engine

GM added flex-fuel capability to the L92 engine in 2009 and named this new version as the L9H. Both engines are basically identical, with only a difference in some fuel injection components. For example, the L92 had standard injectors with 2 holes in the end of the nozzle, while the L9H came with 4-hole nozzle Flex Fuel injectors.

L94 Engine

The L94 engine is a further development of the L9H motor. This version features GM's cylinder deactivation system called Active Fuel Management (AFM). The 6.2L V8 L94 engines were used in Cadillac and GMC vehicles from 2010 to 2014 (Escalade ESV, EXT, Yukon and Yukon XL).

Engine Specs

6.2L Vortec 6200 Engine Common Problems

The older L92 and L9H V8 engines were dependable workhorses. They didn't have many flaws in their design, just simple and reliable power trains. The later version L94, with the cylinder deactivation feature (Active Fuel Management), is considered a less robust engine, but it is still very durable. But even the most reliable workhorses have limits and unique problems. Here below are some of the most common issues with these 6.2-liter Vortec 6200 engines.

Dropped Valve Seats

This is a well known problems on LS‑family rectangle‑port heads related to chronic overheating. The issue is that aluminum heads expand faster than the press‑fit steel seats. Over time, due to wear and tear, the fit may loosen and seats may fall out, causing catastrophic damage to the engine. Regular care of the cooling system (flushing system, replacing deteriorated radiator caps and hoses, checking cooling fan and temperature sensors) really helps to prevent this issue.

Oil Pressure Woes

Quite often there are problems with low oil pressure. Most often, the reason lies in the wear of the camshaft bearings (the ECU may even throw the error P0011). Low oil pressure may also be due to the use of incorrect thin oil, low-quality oil or degraded oil (too long oil change intervals).

Low Idle RPMs

Too low idling speed, less than 650 RPMs, is quite common issue with this engine. In 99% this caused by dirty throttle body.

Loud Operating

Many owners note very loud engine operation when cold, on start up, then when it gets warm it quiets down. Some people complain about the engine sound like a diesel in the morning and even find it embarrassing.

AFM Reliability Issues

The L94 operates with the AFM system, which has been known to cause issues with excessive oil consumption and lifter failure. Older versions of this technology are frequently considered unreliable. Additionally, the constant switching between 8-cylinder and 4-cylinder modes increases stress and wear on internal components.

Reliability Summary

Drawing the line, is it a good or bad? Yes, the 6.2L L92, L9H and L94 are good, robust engines, They are reliable, but not immune to neglect. With proper maintenance, regular oil and filter changes, good fuel, and careful driving, these V8 truck engines can last more than 250,000 miles.