Notice:Do not add too much oil. If the engine
has so much oil that the oil level gets above the
cross-hatched area that shows the proper operating
range, the engine could be damaged.
SeeEngine Compartment
Overview on page 5-14
for the location of the
engine oil ll cap.
Add enough oil to put the level somewhere in the proper
operating range. Push the dipstick all the way back in
when you are through.Checking Engine Oil (ZO6 and ZR1)
A. Engine Oil Dipstick
B. Engine Oil Fill Cap
It is a good idea to check the engine oil level every time
you get fuel. In order to get an accurate reading, the oil
must be warm and the vehicle must be on level ground.
5-21
The engine oil dipstick handle is a yellow loop.
The dipstick is located on the dry sump engine oil tank.
SeeEngine Compartment Overview on page 5-14
for the location of the dry sump engine oil tank.
These vehicles 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 checking
the engine oil level. Follow this procedure closely when
checking the engine oil level.
The engine oil level must be checked when the engine
is warm. Cold oil level in the dry sump tank may not
indicate the actual amount of oil in the system. With
this system, engine oil is contained in an external tank,
separate from the engine. Under normal operating
conditions, the oil pan under the engine does not store
any oil. If the vehicle has been parked for an extended
period without the engine being started, some oil will
seep back into the oil pan, reducing the amount of oil
held in the dry sump tank and there could be no engine
oil at all showing on the dipstick.This is normal since the dipstick is designed to read
engine oil level only after the engine has run long enough
to reach normal operating temperature. Do not add
engine oil based on cold engine dipstick readings.
The engine oil level on the dipstick will also be inaccurate
if checked while the engine is running.
1. To obtain an accurate engine oil level reading,
warm up the engine to at least 175°F (80°C).
Cold oil will not give a correct oil level reading.
2. Once the engine is warm, turn off the engine.
Checking the oil while the engine is running
will result in an incorrect oil level reading.
3. Wait at least ve minutes (but not more than
20 minutes) to allow oil to drain and settle in
the engine.
4. Remove the dipstick from the external engine oil
tank and clean it with a lint-free paper towel or a
cloth. Re-insert the dipstick into the external oil tank,
pushing it all the way in until it stops.
5. Remove the dipstick from the oil tank and read the
level on the cross-hatched area. Oil levels that fall
in the cross-hatched area are normal.
5-22
A. Engine Oil Drain Plugs
B. Seals
1. Remove the two engine oil drain plugs from the
bottom of the engine oil pan. One drain plug drains
the external oil tank via the oil transfer supply line.
The other drain plug drains residual oil from the
crankcase sump. Allow the oil to drain.2. Once the oil has been drained from the engine,
remove the engine oil lter and allow the oil
to drain.
3. Re-install both drain plugs and tighten them to
18 lb ft (25Y).
4. Replace the oil lter and tighten it to 18 lb ft
(25Y). SeeMaintenance Replacement Parts
on page 6-14for the correct lter.
5. Oil is lled through the opening in the top of the
external engine oil tank. Remove the oil ll cap.
6. Add 10.5 quarts (9.9 L) of oil to the oil tank.
SeeCapacities and Specifications on page 5-110.
7. Install the oil ll cap and insert the dipstick,
if removed.
8. Start the engine and let it run at idle for at least
15 seconds. This will circulate the fresh engine
oil through the lubrication system.
9. Shut off the engine and check the oil level
as described under “Checking Engine Oil
(ZO6 and ZR1).” ZO6 Shown, ZR1 Similar
5-24
Engine Oil Additives / Engine Oil
Flushes
Do not add anything to the oil. The recommended
oils with the starburst symbol that meet GM Standard
GM4718M are all that is needed for good performance
and engine protection.
Engine oil system ushes are not recommended and
could cause engine damage not covered by the vehicle
warranty.
Engine Oil Life System
When to Change Engine Oil
This vehicle has a computer that indicates when to
change the engine oil and lter. This is based on engine
revolutions and engine temperature, and not on mileage.
Based on driving conditions, the mileage at which an oil
change is indicated can vary considerably. For the oil life
system to work properly, the system must be reset every
time the oil is changed.Z06 and ZR1 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 lter. SeeEngine Oil on page 5-20.
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 600 miles
(1 000 km). 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 lter 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 3,000 miles (5 000 km) since the last oil
change. Remember to reset the oil life system whenever
the oil is changed.
5-26
Checking Coolant
The vehicle must be on a level surface when checking
the coolant level.
Check to see if coolant is visible in the coolant surge
tank. If the coolant inside the coolant surge tank is boiling,
do not do anything else until it cools down. If coolant
is visible but the coolant level is not at or above the
FULL COLD mark, add a 50/50 mixture of clean,
drinkable water and DEX-COOL coolant at the coolant
recovery tank, but be sure the cooling system is cool
before this is done. SeeEngine Coolant on page 5-34
for more information.
The engine coolant
surge tank is located
toward the rear of the
engine compartment on
the driver side of the
vehicle. SeeEngine
Compartment Overview
on page 5-14for 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
{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.
5-36
If the temperature overheat gage is no longer in the
overheat zone or an overheat warning no longer
displays, the vehicle can be driven. Continue to drive
the vehicle slow for about 10 minutes. Keep a safe
vehicle distance from the car in front of you. If the
warning does not come back on, continue to drive
normally.
If the warning continues, pull over, stop, and park the
vehicle right away.
If there is no sign of steam, idle the engine for
three minutes while parked. If the warning is still
displayed, turn off the engine until it cools down.
Also, see “Overheated Engine Protection Operating
Mode” next in this section.Overheated Engine Protection
Operating Mode
This emergency operating mode lets the vehicle
be driven to a safe place, up to 50 miles (80 km),
in an emergency situation. 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,
there is a signi cant loss in power and engine
performance.
Driving extended distances 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. SeeEngine Oil on page 5-20.
5-41