Engine Fan Noise; Power Steering Fluid - Chevrolet 2007 Silverado 1500 Pickup Owner's Manual

Engine Fan Noise

If your vehicle has a clutched engine cooling fan,
when the clutch is engaged, the fan spins faster to
provide more air to cool the engine. In most
everyday driving conditions, the fan is spinning
slower and the clutch is not fully engaged. This
improves fuel economy and reduces fan noise.
Under heavy vehicle loading, trailer towing, and/or
high outside temperatures, the fan speed increases
as the clutch more fully engages, so you may hear
an increase in fan noise. This is normal and should
not be mistaken as the transmission slipping or
making extra shifts. It is merely the cooling system
functioning properly. The fan will slow down when
additional cooling is not required and the clutch
disengages.
You may also hear this fan noise when you start
the engine. It will go away as the fan clutch
partially disengages.
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If your vehicle has electric cooling fans, you may
hear the fans spinning at low speed during most
everyday driving. The fans may turn off if no cooling
is required. Under heavy vehicle loading, trailer
towing, and/or high outside temperatures, or if you
are operating your air conditioning system, the fans
may change to high speed and you may hear an
increase in fan noise. This is normal and indicates
that the cooling system is functioning properly. The
fans will change to low speed when additional
cooling is no longer required.

Power Steering Fluid

See Engine
Compartment Overview
on page 476 for
reservoir location.