This bulletin applies to 2019-2021 Chevy Blazer, 2016-2019 Camaro and 2017-2021 Colorado vehicles, equipped with a 3.6L engine. The MIL may be on, with engine noise from the front of the engine, and a belt squeak. Technicians may find DTC P0324 (knock sensor system performance) set in the ECM.
This condition may be caused by the water pump. If the condition is bad enough, the engine will pick up noise created by the water pump. Listen to the water pump using a stethoscope or chassis ears for any unusual noise. Watch the knock retard bank to bank on GDS2, then remove the belt and observe knock retard again. If there is a difference, this bulletin applies. Replace the water pump and re-evaluate.
Water pump kit (3.6l LGX)................12707180
