1998 GMC Safari Owner's Manual - Page 244

Engine Fan Noise This vehicle has a clutched engine cooling fan. When the clutch is engaged, fan spins fasterto provide the more air to cool the engine. most everyday driving In conditions, the clutchis not fully engaged. This improves fuel economy and reducesfan noise. Under heavy vehicle loading, trailer towing and/or high outside temperatures, thefan speed increases when the clutch engages. So you may hear an increase fan in noise. This is normal and should not be mistaken as the transmission slipping or making extra shifts. It merely is the cooling system functioning properly. The will fan slow down when additional cooling not required and is the clutch disengages. You may also hear this fan noise when you start the engine. It will go awayas the fan clutch disengages. If a Tire Goes Flat It's unusual for a tire to "blow out" while you're driving, especially if you maintain your tires properly. If air goes out of a tire, it's much more likely to leak out slowly. But if you should ever have a "blowout," here a few are tips about what to expect and what to do: If a front tire fails, the flat tire will create a drag that pulls the vehicle toward that side. Take your foot off the accelerator pedal and grip the steering wheel firmly. Steer to maintain lane position, and then gently brake to a stop well out the traffic lane. of A rear blowout, particularly on a curve, acts much like a skid and may require the same correction you'd use in a skid. In any rear blowout, remove your foot from the accelerator pedal. Get the vehicle under control by steering the way you want the vehicle go. It may be to very bumpy and noisy, but you can still steer. Gently brake to a stop-- well off the road if possible. If a tire goes flat, the next part shows how to use your jacking equipment to change a flat tire safely. 5-22