2007 CHEVROLET OPTRA 5 radiator

Engine Coolant
The cooling system in your vehicle is filled with
DEX-COOL®engine coolant. This coolant is
designed to remain in your vehicle for five years
or 150,000 miles (240 000 km), whichever
occurs first, if you add only DEX-COOL
®extended
life coolant.
The following explains your cooling system and
how to add coolant when it is low. If you have
a problem with engine overheating, seeEngine
Overheating on page 271.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
•Give freezing protection down to
−34°F (−37°C).
•Give boiling protection up to 265°F (129°C).
•Protect against rust and corrosion.
•Help keep the proper engine temperature.
•Let the warning lights and gages work as
they should.Notice:Using coolant other than DEX-COOL
®
may cause premature engine, heater core,
or radiator corrosion. In addition, the engine
coolant may require changing sooner, at
the rst maintenance service after each
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.
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.
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{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.
SeePart D: Recommended Fluids and
Lubricants on page 382for more information.
269

Checking Coolant
The engine coolant surge tank is located in the rear
of the engine compartment on the driver’s side of
the vehicle. SeeEngine Compartment Overview on
page 258for 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.
To check the engine coolant, the vehicle must be
on a level surface. When your engine is cold,
the coolant level should be between the
Maximum (A) and Minimum (B) marks on the
coolant surge tank. The level rises at engine
operation temperature and drops again when the
engine cools down.
270

{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.
Make sure that the air conditioning is turned off.
The coolant level should be between the Minimum
and Maximum marks on the coolant surge tank
when the engine is cool. 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.
274

{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 a proper 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.
{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.
276

1. You can remove the coolant surge tank
pressure cap when the cooling system,
including the coolant surge tank pressure cap
and upper radiator hose, is no longer hot.
Turn the pressure cap slowly counterclockwise
about two or two and one-half turns.
If you hear a hiss, wait for that to stop.
This will allow any pressure still left to be
vented out the discharge hose.
2. Then keep turning the pressure cap slowly,
and remove it.
277

3. Fill the coolant surge tank with the proper
mixture to the Maximum mark on the
coolant surge tank. Wait about five minutes,
then check to see if the level is below the
mark. If the level is below the Maximum mark,
add additional coolant to bring the level up
to the mark. Repeat this procedure until
the level remains constant at the Maximum
mark for at least five minutes.4. With the coolant surge tank pressure cap off,
start the engine and let it run until you can
feel the upper radiator hose getting hot.
Watch out for the engine cooling fan.
By this time, the coolant level inside the
coolant surge tank may be lower. If the level
is lower than the Maximum mark, add
more of the proper mixture to the coolant
surge tank until the level reaches the mark.
5. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
See your dealer, if necessary.
278

Headlamp Aiming
Headlamp aim has been preset at the factory and
should need no further adjustment.
However, if your vehicle is damaged in an accident,
the headlamp aim may be affected. Aim adjustment
to the low-beam headlamps may be necessary if it
is difficult to see the lane markers (for horizontal
aim), or if oncoming drivers flash their high-beam
headlamps at you (for vertical aim).
If you believe your headlamps need to be
re-aimed, it is recommend that you take the vehicle
to your dealer for service.
Bulb Replacement
For the proper type of replacement bulbs, see
Replacement Bulbs on page 301.
For any bulb changing procedure not listed in this
section, contact your dealer.
Halogen Bulbs
{CAUTION:
Halogen bulbs have pressurized gas
inside and can burst if you drop or
scratch the bulb. You or others could be
injured. Be sure to read and follow the
instructions on the bulb package.
Headlamps
To replace a headlamp bulb, do the following:
1. Open the hood. SeeHood Release on
page 257for more information.
2. For wagon models, remove the two bolts from
the top of the headlamp assembly and one
nut on the inside that retains the headlamp
assembly.
For hatchback models, remove the four screws
and the radiator grill. Then remove the
three bolts and the headlamp assembly.
290