2004 GMC Envoy Owner's Manual - Page 100

Engine Exhaust {CAUTION: Engine exhaust can kill. It contains the gas carbon monoxide (CO), which you can not see or smell. It can cause unconsciousness and death. You might have exhaust coming in if: • Your exhaust system sounds strange or different. • Your vehicle gets rusty underneath. • Your vehicle was damaged in a collision. • Your vehicle was damaged when driving over high points on the road or over road debris. • Repairs were not done correctly. • Your vehicle or exhaust system had been modified improperly. If you ever suspect exhaust is coming into your vehicle: • Drive it only with all the windows down to blow out any CO; and • Have your vehicle fixed immediately. 2-34 Running Your Engine While You Are Parked It is better not to park with the engine running. But if you ever have to, here are some things to know. {CAUTION: Idling the engine with the climate control system off could allow dangerous exhaust into your vehicle. See the earlier Caution under Engine Exhaust on page 2-34. Also, idling in a closed-in place can let deadly carbon monoxide (CO) into your vehicle even if the climate control fan is at the highest setting. One place this can happen is a garage. Exhaust - with CO - can come in easily. NEVER park in a garage with the engine running. Another closed-in place can be a blizzard. See Winter Driving on page 4-40.