The 2020 Encore GX and 2021 Trailblazer feature the new 1.2L turbocharged engine (RPO LIH). (Fig. 20) The engine may have a noticeable sound under certain circumstances.
Fig. 20
Drivers may hear a deep thudding sound from the engine when it is operating in the lower speed range (typically less than 2,000 rpm) during a launch at moderate to high throttle inputs. The sound may be more pronounced when the engine is cold compared to when it has warmed up.
TIP: An example of the engine sound is included in Bulletin #20-NA-084 when viewed in GM’s Service Information.
The sound is inherent to the small-displacement, power-dense design of the 1.2L engine and is considered a normal operating condition. The sound does not affect the performance or durability of the engine.
– Thanks to Jeff Kropp