Engine Exhaust
WARNING
Engine exhaust contains carbon monoxide (CO) which cannot be seen or smelled. Exposure to CO can cause unconsciousness and even death.
Exhaust may enter the vehicle if:
• The vehicle idles in areas with poor ventilation (parking garages, tunnels, deep snow that may block underbody airflow or tail pipes).
• The exhaust smells or sounds strange or different.
• The exhaust system leaks due to corrosion or damage.
• The vehicle exhaust system has been modified, damaged or improperly repaired.
• There are holes or openings in the vehicle body from damage or aftermarket modifications that are not completely sealed.
If unusual fumes are detected or if it is suspected that exhaust is coming into the vehicle:
• Drive it only with the windows completely down.
• Have the vehicle repaired immediately.
Never park the vehicle with the engine running in an enclosed area such as a garage or a building that has no fresh air ventilation.
See also:
New for 2011
The Sierra Hybrid gets GM's OnStar 9.0 telematics system that GM says
provides better voice recognition. GM also said they have worked to cut down on
the amount of wind noise occupants hear. ...
Engine Oil Additives/Engine Oil Flushes
Do not add anything to the oil. The recommended oils with the dexos specification and displaying the dexos certification mark are all that is needed for good performance and engine protection.
Engine ...
Hill Start Assist (HSA)
This vehicle has a Hill Start Assist (HSA) feature, which may be useful when the vehicle is stopped on a grade. This feature is designed to prevent the vehicle from rolling, either forward or rearward ...





