The 6.2L V8 engine (RPO L87) and 6.6L V8 engine (RPO L8T) may produce several different sounds under various conditions on some 2019-2023 Silverado 1500, Silverado 2500/3500, Tahoe, Suburban, Sierra 1500, Sierra 2500/3500, Yukon and Escalade models. Some of these sounds, which may be described as a chirp, squeak or sputter, are normal conditions based on the current operation of the engine.
To help clarify the sounds and their source, Bulletin #22-NA-218 includes several examples of the sounds as well as when they typically occur, such as when the spark timing is retarded. The sounds are more noticeable on the 6.2L engine (L87) and 6.6L engine (L8T) (Fig. 8) than on the 5.3L engine (RPO L84).
Fig. 8
Keep in mind that engine sounds will be more prominent when the vehicle is next to a reflecting surface, including walls and guardrails or when another vehicle is in an adjacent lane while driving.
There are four common sounds highlighted in the bulletin that may be noticeable.
Catalyst Light Off – Occurs on start when spark retard is required for catalyst rapid warm up and may last approximately 30 seconds. Catalyst rapid warm up is not triggered on all starts. The vehicle generally must have sat for an hour or more.
Engine Restart – Following complete engine shutdown coasting down through approximately 14 MPH (22 km/h), the noise will only last for about 1 second. Spark is retarded to prevent engine overspeed/torque bump.
Auto-Start – At the end of an engine stop/start shutdown, the noise will last for less than 1 second. Spark is retarded to prevent engine overspeed/torque bump.
Throttle Blip – Light throttle blip in Park/Neutral. The sound is rarely noticed and may be hard to reproduce. Spark is retarded to prevent engine overspeed.
Do not attempt to compare these sounds to similar vehicles as the noise may be different from one vehicle to another, which could lead to unnecessary repairs. These sounds are a normal operating characteristic of the engine and any repairs should not be performed. Replacing the engine or internal components for these sounds will not reduce or eliminate the condition.
For more information, and to listen to the sound clip examples, refer to Bulletin #22-NA-218.
– Thanks to Bryan Salisbury
