Coolant Surge Tank Pressure Cap
The coolant surge tank
pressure cap must be fully
installed on the coolant
surge tank.
Notice:Your pressure cap is a pressure-type cap
and must be tightly installed to prevent coolant loss
and possible engine damage from overheating.
See“Capacities and Specifications”for more
information.
Engine Overheating
You willfind a coolant temperature gage on your
vehicle’s instrument panel. SeeEngine Coolant
Temperature Gage on page 3-36. In addition, you will
find a LOW COOLANT, ENGINE OVERHEATED and a
REDUCED ENGINE POWER message in the DIC on
the instrument panel. SeeDriver Information Center
(DIC) on page 3-42.
Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
REDUCED ENGINE POWER message is displayed, an
overheat protection mode which alternatesfiring
groups of cylinders helps prevent engine damage. In
this mode, you will notice a loss in power and engine
performance. This operating mode allows your vehicle to
be driven to a safe place in an emergency. Driving
extended miles (km) and/or towing a trailer in the
overheat protection mode should be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any repair.
The engine oil will be severely degraded. Repair the
cause of coolant loss, change the oil and reset the oil
life system. See“Engine Oil”in the Index.
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2003 - Sierra Denali
How to Check Power Steering Fluid
Turn the key off, let the engine compartment cool down,
wipe the cap and the top of the reservoir clean, then
unscrew the cap and wipe the dipstick with a clean rag.
Replace the cap and completely tighten it. Then remove
the cap again and look at thefluid level on the dipstick.
The level should be at the FULL COLD mark. If
necessary, add only enoughfluid to bring the level up to
the mark.
What to Use
To determine what kind offluid to use, seePart D:
Recommended Fluids and Lubricants on page 6-15.
Always use the properfluid. Failure to use the proper
fluid can cause leaks and damage hoses and seals.
Windshield Washer Fluid
What to Use
When you need windshield washerfluid, be sure to read
the manufacturer’s instructions before use. If you will
be operating your vehicle in an area where the
temperature may fall below freezing, use afluid that has
sufficient protection against freezing. SeeEngine
Compartment Overview on page 5-12for reservoir
location.
Adding Washer Fluid
Open the cap with the
washer symbol on it. Add
washerfluid until the
tank is full.
Notice:
•When using concentrated washerfluid, follow the
manufacturer’s instructions for adding water.
•Don’t mix water with ready-to-use washerfluid.
Water can cause the solution to freeze and
damage your washerfluid tank and other parts of
the washer system. Also, water doesn’t clean as
well as washerfluid.
•Fill your washerfluid tank only three-quarters full
when it’s very cold. This allows for expansion if
freezing occurs, which could damage the tank if
it is completely full.
•Don’t use engine coolant (antifreeze) in your
windshield washer. It can damage your washer
system and paint.
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