
Additives
To provide cleaner air, all gasolines in the United States
are now required to contain additives that help prevent
engine and fuel system deposits from forming, allowing
the emission control system to work properly. In most
cases, nothing should have to be added to the fuel.
However, some gasolines contain only the minimum
amount of additive required to meet U.S. Environmental
Protection Agency regulations. To help keep fuel
injectors and intake valves clean, or if the vehicle
experiences problems due to dirty injectors or valves,
look for gasoline that is advertised as TOP TIER
Detergent Gasoline.
For customers who do not use TOP TIER Detergent
Gasoline regularly, one bottle of GM Fuel System
Treatment PLUS, added to the fuel tank at every engine
oil change, can help clean deposits from fuel injectors
and intake valves. GM Fuel System Treatment PLUS
is the only gasoline additive recommended by General
Motors.
Also, your dealer/retailer has additives that will help
correct and prevent most deposit‐related problems. Gasolines containing oxygenates, such as ethers
and ethanol, and reformulated gasolines might be
available in your area. We recommend that you use
these gasolines, if they comply with the specifications
described earlier. However, E85 (85% ethanol) and
other fuels containing more than 10% ethanol must
not be used in vehicles that were not designed for
those fuels.
Notice:
This vehicle was not designed for fuel
that contains methanol. Do not use fuel containing
methanol. It can corrode metal parts in the fuel
system and also damage plastic and rubber parts.
That damage would not be covered under the
vehicle warranty.
Some gasolines that are not reformulated for low
emissions can contain an octane-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl
(MMT); ask the attendant where you buy gasoline
whether the fuel contains MMT. We recommend against
the use of such gasolines. Fuels containing MMT can
reduce the life of spark plugs and the performance
of the emission control system could be affected.
The malfunction indicator lamp might turn on. If this
occurs, return to your dealer/retailer for service.
6-8

Z06, ZR1, and Grand Sport models have a
racetrack‐ready dry sump engine lubrication system.
This high‐performance system operates differently
than a standard engine lubrication system and requires
a special procedure when changing the engine oil and
filter. See Engine Oil on page 6‑19.
When the system has calculated that oil life has been
diminished, it indicates that an oil change is necessary.
A CHANGE ENGINE OIL message comes on. Change
the oil as soon as possible within the next 1 000 km
(600 miles). It is possible that, if driving under the best
conditions, the oil life system might not indicate that
an oil change is necessary for over a year. However,
the engine oil and filter must be changed at least once
a year and at this time the system must be reset.
Your dealer/retailer has trained service people who
will perform this work using genuine parts and reset
the system. It is also important to check the oil regularly
and keep it at the proper level.
If the system is ever reset accidentally, the oil must be
changed at 5 000 km (3,000 miles) since the last oil
change. Remember to reset the oil life system
whenever the oil is changed.How to Reset the Engine Oil Life
System
The Engine Oil Life System calculates when to
change the engine oil and filter based on vehicle use.
Whenever the oil is changed, reset the system so it
can calculate when the next oil change is required.
If a situation occurs where the oil is changed prior to
a CHANGE ENGINE OIL message being turned on,
reset the system.
To reset the CHANGE ENGINE OIL message after an
oil change: 1. Press the TRIP button so the OIL LIFE percentage is displayed.
2. Press RESET and hold for two seconds. OIL LIFE REMAINING 100% will appear.
If the CHANGE ENGINE OIL message comes back on
when the vehicle is started, the engine oil life system
has not reset. Repeat the procedure.
6-26

Automatic Transmission Fluid
How to Check Automatic Transmission
Fluid
It is not necessary to check the transmission fluid level.
A transmission fluid leak is the only reason for fluid
loss. If a leak occurs, take the vehicle to your dealer/
retailer service department and have it repaired as soon
as possible.
There is a special procedure for checking and changing
the transmission fluid. Because this procedure is
difficult, you should have this done at your dealer/
retailer service department. Contact your dealer/retailer
for additional information or the procedure can be found
in the service manual. To purchase a service manual,
see Service Publications Ordering Information
on
page 8‑16.
Notice: Use of the incorrect automatic transmission
fluid may damage the vehicle, and the damages may
not be covered by the vehicle's warranty. Always
use the automatic transmission fluid listed in
Recommended Fluids and Lubricants on page 7‑10. Change the fluid and filter at the intervals listed in
Scheduled Maintenance
on page 7‑3, and be sure
to use the fluid listed in Recommended Fluids and
Lubricants on page 7‑10.
Manual Transmission Fluid
It is not necessary to check the manual transmission
fluid level. A transmission fluid leak is the only reason
for fluid loss. If a leak occurs, take the vehicle to your
dealer/retailer service department and have it repaired
as soon as possible. See Recommended Fluids and
Lubricants
on page 7‑10for the proper fluid to use.
Hydraulic Clutch
It is not necessary to regularly check clutch fluid unless
you suspect there is a leak in the system. Adding fluid
will not correct a leak. A fluid loss in this system could
indicate a problem. Have the system inspected and
repaired.
6-31

{WARNING:
An electric engine cooling fan under the hood can
start up even when the engine is not running and
can cause injury. Keep hands, clothing, and tools
away from any underhood electric fan.
{WARNING:
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 fire, and you could be burned.
Get any leak fixed before you drive the vehicle. Notice:
Using coolant other than DEX-COOL
®can
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant could
require changing sooner, at 50 000 km (30,000 miles)
or 24 months, whichever occurs first. Any repairs
would not be covered by the vehicle warranty.
Always use DEX-COOL
®(silicate-free) coolant
in the vehicle.
Cooling System (Intercooler)
The 6.2L LS9 supercharged V8 engine has an
intercooler cooling system. See Engine Compartment
Overview
on page 6‑14for location of the intercooler.
The intercooler cooling system has a special procedure
for draining and adding coolant. Because this procedure
is difficult, see your dealer/retailer for service if the
intercooler is low on coolant. The procedure can also
be found in the service manual. To purchase a service
manual, see Service Publications Ordering Information
on page 8‑16.
6-33

Checking Coolant
1. Verify that the engine and intercooler are no longer hot.
2. Place a cloth to absorb possible coolant loss under the driver's side bleeder valve (A). 3. Loosen, but do not completely unscrew the bleeder
valve to check for coolant in the system.
4. Tighten the bleeder valve if there is coolant flowing out of the bleeder valve.
5. If there is no coolant flowing out of the bleeder valve, there could be a leak in the system. Tighten
the bleeder valve and contact your dealer/retailer
for service.
Engine Coolant
The cooling system in the vehicle is filled with
DEX-COOL®engine coolant. This coolant is designed
to remain in the vehicle for five years or 240 000 km
(150,000 miles), whichever occurs first.
The following explains the cooling system and how
to check and add coolant when it is low. If there is
a problem with engine overheating, see Engine
Overheating on page 6‑38.
6-34

The engine coolant surge
tank is located toward
the rear of the engine
compartment on the
driver side of the vehicle.
See Engine Compartment
Overview
on page 6‑14for more information on
location.
When the engine is cold, the coolant level should be at
the FULL COLD mark on the coolant surge tank.
When the engine is hot, the level could be higher
than the FULL COLD line. If the coolant is below the
FULL COLD line when the engine is hot, there could
be a leak in the cooling system.
If the coolant is low, add the coolant or take the vehicle
to a dealer/retailer for service.
How to Add Coolant to the Coolant
Surge Tank
{WARNING:
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.
{WARNING:
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.
6-36

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. Any time during
this procedure, 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, add
more of the proper mixture to the coolant surge
tank until the level stabilizes at the FULL COLD
mark on the coolant surge tank. 5. Replace the pressure cap. Be sure the pressure
cap is hand-tight and fully seated.
Check the level in the surge tank when the system
has cooled down. If the coolant is not at the proper
level, repeat Steps 1 through 4, then reinstall the
pressure cap. If the coolant is not at the proper
level when the system cools down again, see your
dealer/retailer.
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.
Engine Overheating
The vehicle has several indicators to warn of engine
overheating.
There is an engine coolant temperature gauge on
the instrument panel cluster. See Engine Coolant
Temperature Gauge
on page 4‑40. The vehicle may
also display a COOLANT OVER TEMPERATURE
message on the Driver Information Center (DIC).
See DIC Warnings and Messages
on page 4‑52for more information.
You may decide not to lift the hood but to get service
help right away. See Roadside Assistance Program
on
page 8‑7.
6-38

If you do decide to lift the hood , make sure the vehicle
is parked on a level surface.
Then check to see if the engine cooling fan is running.
If the engine is overheating, the fan should be running.
If it is not, do not continue to run the engine and have
the vehicle serviced.
Notice: Engine damage from running your engine
without coolant is not covered by your warranty.
See Overheated Engine Protection Operating Mode
on page 6‑41for information on driving to a safe
place in an emergency.
Notice: If the engine catches fire while driving
with no coolant, the vehicle can be badly damaged.
The costly repairs would not be covered by the
vehicle warranty. See Overheated Engine Protection
Operating Mode
on page 6‑41for information on
driving to a safe place in an emergency.
If Steam Is Coming From Your Engine
{WARNING:
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 fire. You or
others could be badly burned. Stop the engine if
it overheats, and get out of the vehicle until the
engine is cool.
See Overheated Engine Protection Operating
Mode
on page 6‑41for information on driving to
a safe place in an emergency.
6-39