Engine Oil Additives / Engine Oil Flushes
Do not add anything to the oil. The recommended oils with the starburst symbol that meet GM Standard GM6094M are all that is needed for good performance and engine protection.
Engine oil system flushes are not recommended and could cause engine damage not covered by the vehicle warranty.
See also:
Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn the ignition to LOCK/OFF
in each shift lever position.
The ignition should turn to LOCK/OFF only when the shift lever is in P (Park).
...
What to Use
WARNING:
Adding only plain water to the cooling system can
be dangerous. Plain water, or some other liquid
such as alcohol, can boil before the proper coolant
mixture will. The vehicle’s cool ...
Parking Brake
The vehicle has an Electric Parking Brake (EPB). The switch for the EPB is on the center console.
The EPB can always be activated, even if the ignition is off. To prevent draining the battery, avoi ...