1994 GMC Jimmy Owner's Manual - Page 220

Engine Fan Noise This vehicle has a clutched engine cooling fan. When the clutch is engaged, the fan spins faster to provide more air to cool the engine. most every day In driving conditions the clutch not engaged.This improves fuel economy is and reduces fan noise. Under heavy vehicle loading, trailer towing and/or high outside temperatures, the fan speed increases when the clutch engages. So you may hear an increase in fan noise.This is normal and should not be It is mistaken as the transmission slipping or making extra shifts. merely the cooling system functioning properly. fan will slow down when The additional cooling is not required and the clutch disengages. You may also hear this fan noise when start the engine. will go away you It as the fan clutch disengages. If a Tire Goes Flat It's unusualfor a tire to "blow out" while you're driving, especiallyif you maintain your tires properly. air goes outof a tire, it's much more likely to If leak out slowly. But you should ever have "blowout," here are few tips if a a about what to expect and what to do: a If a front tire fails, the flat tire will createdrag that pulls the vehicle toward that side. Take your foot the accelerator pedal and grip the off a steering wheel firmly. Steer to maintain lane position, then gently brake to stop well outof the traffic lane. A rear blowout, particularly ona curve, acts much like skid and may a skid. In any rear blowout, remove require the same correction you'd use ain your foot from the accelerator pedal. Get vehicle under control by the steering theway you want the vehicle to go. It may be very bumpy and noisy, but you can still steer. Gently brake to stop, welloff the road if a possible. If a tire goesflat, the next section shows how to use your jacking equipment to change a flat tire safely. 5-18