engine CHEVROLET COBALT 2008 1.G Repair Manual

If you want to do some of your own service work,
you should use the proper service manual. It tells
you much more about how to service your vehicle
than this manual can. To order the proper service
manual, seeService Publications Ordering Information
on page 7-16.
Your vehicle has an airbag system. Before attempting
to do your own service work, seeServicing Your
Airbag-Equipped Vehicle on page 1-66.
You should keep a record with all parts receipts and
list the mileage and the date of any service work
you perform. SeeMaintenance Record on page 6-16.
Adding Equipment to the
Outside of Your Vehicle
Things you might add to the outside of your vehicle
can affect the airow around it. This can cause
wind noise and can affect fuel economy and windshield
washer performance. Check with your dealer/retailer
before adding equipment to the outside of your vehicle.
Fuel
Use of the recommended fuel is an important part of
the proper maintenance of your vehicle. To help
keep the engine clean and maintain optimum vehicle
performance, we recommend the use of gasoline
advertised as TOP TIER Detergent Gasoline.
The 8th digit of the Vehicle Identication Number (VIN)
shows the code letter or number that identies your
vehicle’s engine. The VIN is at the top left of the
instrument panel. SeeVehicle Identification Number
(VIN) on page 5-104.
Gasoline Octane
If your vehicle has the 2.2L L4 engine (VIN Code F),
use regular unleaded gasoline with a posted octane
rating of 87 or higher. If the octane rating is less than 87,
you might notice an audible knocking noise when you
drive, commonly referred to as spark knock. If this
occurs, use a gasoline rated at 87 octane or higher as
soon as possible. If you are using gasoline rated at
87 octane or higher and you hear heavy knocking,
the engine needs service.
5-5

If your vehicle has the 2.4L L4 engine (VIN Code B),
use premium unleaded gasoline with a posted octane
rating of 91 or higher. You can also use regular
unleaded gasoline rated at 87 octane or higher, but
your vehicle’s acceleration could be slightly reduced,
and you might notice a slight audible knocking
noise, commonly referred to as spark knock. If the
octane is less than 87, you might notice a heavy
knocking noise when you drive. If this occurs, use a
gasoline rated at 87 octane or higher as soon as
possible. Otherwise, you could damage the engine.
If you are using gasoline rated at 87 octane or higher
and you hear heavy knocking, the engine needs service.
Gasoline Specications
At a minimum, gasoline should meet ASTM
specication D 4814 in the United States or
CAN/CGSB-3.5 or 3.511 in Canada. Some gasolines
contain an octane-enhancing additive called
methylcyclopentadienyl manganese tricarbonyl (MMT).
We recommend against the use of gasolines
containing MMT. SeeAdditives on page 5-7for
additional information.
California Fuel
If your vehicle is certied to meet California Emissions
Standards, it is designed to operate on fuels that
meet California specications. See the underhood
emission control label. If this fuel is not available
in states adopting California emissions standards, your
vehicle will operate satisfactorily on fuels meeting
federal specications, but emission control system
performance might be affected. The malfunction
indicator lamp could turn on and your vehicle might fail
a smog-check test. SeeMalfunction Indicator Lamp
on page 3-35. If this occurs, return to your authorized
dealer/retailer for diagnosis. If it is determined that
the condition is caused by the type of fuel used,
repairs might not be covered by your warranty.
5-6

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, you should not have to add anything 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 your vehicle experiences
problems due to dirty injectors or valves, look for gasoline
that is advertised as TOP TIER Detergent Gasoline.
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 specications 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:Your 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 your
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.
Fuels in Foreign Countries
If you plan on driving in another country outside the
United States or Canada, the proper fuel might be
hard to nd. Never use leaded gasoline or any other
fuel not recommended in the previous text on fuel.
Costly repairs caused by use of improper fuel would
not be covered by your warranty.
To check the fuel availability, ask an auto club,
or contact a major oil company that does business
in the country where you will be driving.
5-7

Filling the Tank
{CAUTION:
Fuel vapor burns violently and a fuel re can
cause bad injuries. To help avoid injuries
to you and others, read and follow all the
instructions on the pump island. Turn off your
engine when you are refueling. Do not smoke
if you are near fuel or refueling your vehicle.
Do not use cellular phones. Keep sparks,
ames, and smoking materials away from fuel.
Do not leave the fuel pump unattended when
refueling your vehicle. This is against the law
in some places. Do not re-enter the vehicle
while pumping fuel. Keep children away from
the fuel pump; never let children pump fuel.The tethered fuel cap is located behind a hinged fuel
door on the passenger’s side of the vehicle.
To remove the fuel cap, turn it slowly counterclockwise.
The fuel cap has a spring in it; if the cap is released
too soon, it will spring back to the right.
While refueling, hang the tethered fuel cap from the
hook on the fuel door.
5-8

Filling a Portable Fuel Container
{CAUTION:
Never ll a portable fuel container while it
is in your vehicle. Static electricity discharge
from the container can ignite the fuel vapor.
You can be badly burned and your vehicle
damaged if this occurs. To help avoid injury
to you and others:
Dispense fuel only into approved
containers.
Do not ll a container while it is inside a
vehicle, in a vehicle’s trunk, pickup bed,
or on any surface other than the ground.
Bring the ll nozzle in contact with the
inside of the ll opening before operating
the nozzle. Contact should be maintained
until the lling is complete.
Do not smoke while pumping fuel.
Do not use a cellular phone while
pumping fuel.
Checking Things Under
the Hood
{CAUTION:
An electric fan under the hood can start up
and injure you even when the engine is not
running. Keep hands, clothing, and tools
away from any underhood electric fan.
{CAUTION:
Things that burn can get on hot engine parts
and start a re. These include liquids like fuel,
oil, coolant, brake uid, windshield washer
and other uids, and plastic or rubber. You or
others could be burned. Be careful not to drop
or spill things that will burn onto a hot engine.
5-10

Engine Compartment Overview
When you open the hood on the 2.2L L4 engine (2.4L L4 engine similar), here is what you will see:
5-12

A. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-18.
B. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-13.
C. Engine Oil Dipstick (Out of View). See “Checking
Engine Oil” underEngine Oil on page 5-13.
D. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-31andHydraulic Clutch
on page 5-20.
E. Engine Compartment Fuse Block. SeeEngine
Compartment Fuse Block on page 5-108.
F. Remote Positive (+) Terminal. SeeJump Starting
on page 5-34.
G. Remote Negative (−) Terminal. SeeJump Starting
on page 5-34.
H. Engine Coolant Surge Tank. SeeCooling System
on page 5-25.
I. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-30.Engine Oil
Checking Engine Oil
It is a good idea to check the engine oil 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.
The engine oil dipstick handle is a yellow loop. See
Engine Compartment Overview on page 5-12for
the location of the engine oil dipstick.
1. Turn off the engine and give the oil several minutes
to drain back into the oil pan. If you do not do this,
the oil dipstick might not show the actual level.
2. Pull the dipstick and clean it with a paper towel or
cloth, then push it back in all the way. Remove it
again, keeping the tip down and check the level.
5-13

When to Add Engine Oil
If the oil is below the MIN (minimum) mark, add at least
one quart/liter of the recommended oil. This section
explains what kind of oil to use. For engine oil crankcase
capacity, seeCapacities and Specifications on
page 5-112.
Notice:Do not add too much oil. If the engine
has so much oil that the oil level gets above the
upper mark that shows the proper operating range,
the engine could be damaged.SeeEngine Compartment
Overview on page 5-12
for the location of the
engine oil ll cap.
Be sure to 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.
5-14

What Kind of Engine Oil to Use
Look for three things:
GM6094M
Your vehicle’s engine requires oil meeting
GM Standard GM6094M. Look for and use
only an oil that meets GM Standard GM6094M.
SAE 5W-30
As shown in the viscosity chart, SAE 5W-30
is best for your vehicle.These numbers on an oil container show its
viscosity, or thickness. Do not use other viscosity
oils such as SAE 20W-50.
American Petroleum Institute (API) starburst symbol
Oils meeting these
requirements should
have the starburst
symbol on the container.
This symbol indicates
that the oil has been
certied by the American
Petroleum Institute (API).
Look for this information on the oil container, and
use only those oils that are identied as meeting GM
Standard GM6094M and have the starburst symbol
on the front of the oil container.
Notice:Use only engine oil identied as meeting
GM Standard GM6094M and showing the American
Petroleum Institute Certied For Gasoline Engines
starburst symbol. Failure to use the recommended
oil can result in engine damage not covered by
your warranty.
5-15

If you are in an area of extreme cold, where the
temperature falls below−20°F (−29°C), it is
recommended that you use either an SAE 5W-30
synthetic oil or an SAE 0W-30 oil. Both provide easier
cold starting and better protection for the engine at
extremely low temperatures.
Engine Oil Additives
Do not add anything to the oil. The recommended
oils with the starburst symbol that meet GM Standard
GM6094M are all you need for good performance
and engine protection.
Engine Oil Life System
When to Change Engine Oil
Your vehicle has the Engine Oil Life System, a computer
system that lets you know 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
will be indicated can vary considerably. For the oil life
system to work properly, you must reset the system
every time the oil is changed.When the system has calculated that oil life has
been diminished, it will indicate that an oil change is
necessary. A CHANGE OIL SOON message will come
on. SeeDIC Warnings and Messages on page 3-43.
Change the oil as soon as possible within the next
600 miles (1 000 km). It is possible that, if you
are 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, you must
change the oil at 3,000 miles (5 000 km) since the
last oil change. Remember to reset the oil life system
whenever the oil is changed.
5-16