2007 CHEVROLET CORVETTE engine

What to Use
Use a mixture of one-half clean, drinkable water
and one-half DEX-COOL®coolant which will
not damage aluminum parts. If you use this coolant
mixture, you do not need to add anything else.
{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water,
or some other liquid such as alcohol, can
boil before the proper coolant mixture will.
Your vehicle’s coolant warning system
is set for the proper coolant mixture. With
plain water or the wrong mixture, your
engine could get too hot but you would
not get the overheat warning. Your engine
could catch re and you or others could
be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.Notice:If you use an improper coolant
mixture, your engine could overheat and be
badly damaged. The repair cost would not be
covered by your warranty. Too much water
in the mixture can freeze and crack the engine,
radiator, heater core, and other parts.
If you have to add coolant more than four times
a year, have your dealer check your cooling
system.
Notice:If you use extra inhibitors and/or
additives in your vehicle’s cooling system,
you could damage your vehicle. Use only
the proper mixture of the engine coolant
listed in this manual for the cooling system.
SeeRecommended Fluids and Lubricants
on page 443for more information.
348

Checking Coolant
The engine coolant
surge tank is located
toward the rear of the
engine compartment
on the driver’s side of
the vehicle. SeeEngine
Compartment Overview
on page 330for more
information on location.
{CAUTION:
Turning the surge tank pressure cap when
the engine and radiator are hot can allow
steam and scalding liquids to blow out
and burn you badly. Never turn the surge
tank pressure cap — even a little — when
the engine and radiator are hot.The vehicle must be on a level surface. When
your engine is cold, the coolant level should
be at the FULL COLD mark. The FULL COLD
mark is on the front of the coolant surge tank.
Do not overll the surge tank. Too much coolant
can result in an overow when the uid is hot.
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.
{CAUTION:
You can be burned if you spill coolant
on hot engine parts. Coolant contains
ethylene glycol, and it will burn if
the engine parts are hot enough.
Do not spill coolant on a hot engine.
When replacing the pressure cap, make sure
it is hand-tight and fully seated.
349

Coolant Surge Tank Pressure Cap
Notice:If the pressure cap is not tightly
installed, coolant loss and possible engine
damage may occur. Be sure the cap is
properly and tightly secured.
The coolant surge tank pressure cap must
be fully installed on the coolant surge tank.
SeeEngine Compartment Overview on
page 330for more information on location.
Engine Overheating
You will nd an engine coolant temperature
gage on the instrument panel cluster and a
COOLANT OVER TEMPERATURE message
on the Driver Information Center (DIC). See
Engine Coolant Temperature Gage on page 199
andDIC Warnings and Messages on page 214
for more information.
If Steam Is Coming From Your Engine
{CAUTION:
Steam from an overheated engine can
burn you badly, even if you just open
the hood. Stay away from the engine if
you see or hear steam coming from it.
Turn it off and get everyone away from
the vehicle until it cools down. Wait until
there is no sign of steam or coolant
before you open the hood.
If you keep driving when the vehicles
engine is overheated, the liquids in it can
catch re. You or others could be badly
burned. Stop your engine if it overheats,
and get out of the vehicle until the
engine is cool.
CAUTION: (Continued)
350

CAUTION: (Continued)
SeeOverheated Engine Protection
Operating Mode on page 352for
information on driving to a safe place
in an emergency.
Notice:If your engine catches re because
you keep driving with no coolant, your vehicle
can be badly damaged. The costly repairs
would not be covered by your warranty.
SeeOverheated Engine Protection Operating
Mode on page 352for information on driving
to a safe place in an emergency.
If No Steam Is Coming From
Your Engine
If you get an engine overheat warning but see
or hear no steam, the problem may not be
too serious. Sometimes the engine can get a
little too hot when you:
Climb a long hill on a hot day.
Stop after high-speed driving.
Idle for long periods in traffic.
If you get the overheat warning with no sign
of steam, try this for a minute or so:
1. In heavy traffic, let the engine idle in
NEUTRAL (N) while stopped. If it is safe
to do so, pull off the road, shift to PARK (P)
or NEUTRAL (N) and let the engine idle.
2. Turn on your heater to full hot at the
highest fan speed and open the windows
as necessary.
351

If you no longer have the overheat warning,
you can drive. Just to be safe, drive slower for
about 10 minutes. If the warning does not
come back on, you can drive normally.
If the warning continues and you are not
stopped, pull over, stop, and park your vehicle
right away.
If there is still no sign of steam, you can idle the
engine for three minutes while you are parked.
If you still have the warning, turn off the engine
and get everyone out of the vehicle until it
cools down. Also, see “Overheated Engine
Protection Operating Mode” later in this section.
You may decide not to lift the hood but to get
service help right away.Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
messages COOLANT OVER TEMPERATURE
and REDUCED ENGINE POWER are displayed,
along with the Check Engine light, an overheat
protection mode which alternates ring 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; you may drive up to 50 miles (80 km).
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. SeeEngine Oil on page 333.
352

Cooling System
When you decide it is safe to lift the hood,
here is what you will see:
A. Electric Engine Cooling Fan
B. Coolant Surge Tank with Pressure Cap{CAUTION:
An electric engine cooling fan under the
hood can start up even when the engine
is not running and can injure you. Keep
hands, clothing, and tools away from
any underhood electric fan.
If the coolant inside the coolant surge tank is
boiling, do not do anything else until it cools down.
The vehicle should be parked on a level surface.
353

The coolant level should be at the FULL COLD
mark on the front of the coolant surge tank. If it is
not, you may have a leak at the pressure cap or in
the radiator hoses, heater hoses, radiator, water
pump or somewhere else in the cooling system.
{CAUTION:
Heater and radiator hoses, and other
engine parts, can be very hot. Do not
touch them. If you do, you can be burned.
Do not run the engine if there is a leak.
If you run the engine, it could lose all
coolant. That could cause an engine re,
and you could be burned. Get any leak
xed before you drive the vehicle.
If there seems to be no leak, with the engine on,
check to see if the electric engine cooling fan is
running. If the engine is overheating, the fan should
be running. If it is not, your vehicle needs service.Notice:Engine damage from running your
engine without coolant is not covered by your
warranty. SeeOverheated Engine Protection
Operating Mode on page 352for information
on driving to a safe place in an emergency.
Notice:Using coolant other than DEX-COOL
®
may cause premature engine, heater core,
or radiator corrosion. In addition, the engine
coolant could require changing sooner,
at 30,000 miles (50 000 km) or 24 months,
whichever occurs rst. Any repairs would
not be covered by your warranty. Always
use DEX-COOL
®(silicate-free) coolant in
your vehicle.
How to Add Coolant to the Coolant
Surge Tank
If you have not found a problem yet, check
to see if coolant is visible in the surge tank.
If coolant is visible but the coolant level is not
at the FULL COLD mark on the front of the
coolant surge tank, add a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant at
354

the coolant surge tank, but be sure the cooling
system, including the coolant surge tank pressure
cap, is cool before you do it. SeeEngine
Coolant on page 347for more information.
If no coolant is visible in the surge tank, add
coolant as follows:
{CAUTION:
Steam and scalding liquids from a hot
cooling system can blow out and burn
you badly. They are under pressure, and if
you turn the coolant surge tank pressure
cap — even a little — they can come out
at high speed. Never turn the cap when
the cooling system, including the coolant
surge tank pressure cap, is hot. Wait
for the cooling system and coolant
surge tank pressure cap to cool if you
ever have to turn the pressure cap.
{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can
boil before the proper coolant mixture will.
Your vehicle’s coolant warning system is
set for the proper coolant mixture. With
plain water or the wrong mixture, your
engine could get too hot but you would
not get the overheat warning. Your engine
could catch re and you or others could
be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.
Notice:In cold weather, water can freeze and
crack the engine, radiator, heater core and
other parts. Use the recommended coolant
and the proper coolant mixture.
355