Coolant Surge Tank Pressure Cap; Engine Overheating - GMC 2003 Yukon Denali User Manual

Adding Coolant
If you need more coolant, add the proper DEX-COOL@
coolant mixture at the surge tank, but only when the
engine
is
cool.
1
"J
can be burned if you sb... coolant on hot
engine parts. Coolant contains ethylene glycol,
and it will burn if the engine parts are hot
enough. Don't spill coolant on a hot engine.
When replacing the pressure cap, make sure it is
hand-tight.
Coolant Surge Tank Pressure Cap
The coolant surge tank pressure cap must be fully
installed on the coolant surge tank. See Engine
Compartment Overview on page 5-12 for more
information on location.
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 will find a coolant temperature gage on your
vehicle's instrument panel. See Engine Coolant
Temperature Gage on page 3-36.
in
addition, yoti ill
find a LOW COOLANT, ENGINE COOLANT HOT,
ENGINE OVERHEATED and a REDUCED ENGINE
POWER message in the DIC on the instrument panel.
See DIC Warnings and Messages on page 3-52.
Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
REDUCED ENGINE POWER message is displayed, an
overheat protection mode which alternates firing
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 repa
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.
5-25