1998 GMC Suburban Owner's Manual - Page 107

Engine Exhaust Running Your Engine While You're Parked It's better not to park with the engine running. But if to know. evt IOU ' we to, hl On.1 * Engine exhaust cankill. It contains the gas carbon monoxide(CO), which you can't see or smell. It can cause unconsciousness and death. You might have exhaust coming in if: Your exhaust system sounds strange or different. 0 Your vehicle gets rusty underneath. 0 Your vehicle was damaged in a collision. 0 Your vehicle was damaged when driving over high points on the road or over road debris. Repairs weren't done correctly. 0 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. Idling the enginewith the air system controloff could allow dangerous exhaust into your vehicle (see the earlier Caution under "Engine Exhaust"). Also, idling in a closed-in place can let deadly carbon monoxide (CO) into your vehicle even if the fan switch is at the highest setting. One place this can happen is a garage. Exhaust with CO can come ineasily. NEVER park ina garage with the engine running. Another closed-in place can be a blizzard. (See "Blizzard" in the Index.) -- -- 2-29