2007 CHEVROLET IMPALA engine overheat

If No Steam Is Coming From
Your Engine
An overheat warning can indicate a serious
problem.
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.
Tow a trailer.
If an overheat warning occurs without any 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. Set the heater at the highest setting and the
fan at the highest speed and open the
windows as necessary.If the overheat warning no longer exists, the
vehicle can be driven. Just to be safe, drive slower
for about 10 minutes. If the warning does not
come back on, the vehicle can be driven normally.
If the warning continues, and you have not
stopped, pull over, stop, and park the vehicle
right away.
If there is still no sign of steam, idle the engine
for three minutes while parked. If the warning
is still there, 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.
325

Overheated Engine Protection
Operating Mode
This emergency operating mode allows your
vehicle to be driven to a safe place in an
emergency situation. If an overheated engine
condition exists, an overheat protection mode
which alternates ring groups of cylinders helps
prevent engine damage. In this mode, you
will notice a signicant loss in power and engine
performance. The coolant temperature gage
will indicate an overheat condition exists. Driving
extended miles (km) and/or towing a trailer 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 310.
Cooling System
When you decide it is safe to lift the hood, here is
what you will see:
A. Coolant Recovery Tank
B. Pressure Cap
C. Electric Engine Cooling Fans
3.5L V6 Engine shown, 3.9L Engine similar
326

When the engine is cold, the coolant level should
be at or above the cold ll line on the coolant
recovery tank. To check the coolant level, look
for the cold ll line on the side of the coolant
recovery tank that faces the engine. If the level is
not correct, there may be 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 fans
are running. If the engine is overheating, the fans
should be running. If the fans are not running,
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 326for 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.
328

How to Add Coolant to the Coolant
Recovery Tank
{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.If you have not found a problem yet, but the
coolant level is not at the cold ll line, add a
50/50 mixture of clean, drinkable water and
DEX-COOL
®engine coolant at the coolant
recovery tank. SeeEngine Coolant on page 320
for more information.
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.
When the coolant level in the coolant recovery
tank is at the cold ll line, start the vehicle.
329

If the overheat warning continues, there is
one more thing you can try. You can add the
proper coolant mixture directly to the cooling
system through the coolant ll neck on the engine,
but be sure the system is cool before you do it.
{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 radiator pressure cap — even
a little — they can come out at high
speed. Never turn the cap when the
cooling system, including the radiator
pressure cap, is hot. Wait for the cooling
system and radiator pressure cap to cool
if you ever have to turn the pressure cap.
How to Add Coolant to the Cooling
System
Notice:Your engine has a specic cooling
system drain and ll procedure. Failure
to follow this procedure could cause your
engine to overheat and be severely damaged.
If your engine’s cooling system needs to
be drained and re-lled, please see your
dealer/retailer.
1. You can remove the
pressure cap when
the cooling system,
including the
pressure cap and
upper radiator hose
is no longer hot.
Turn the pressure
cap slowly
counterclockwise.
If you hear a hiss, wait for that to stop. A hiss
means that there is still some pressure left.
330

Engine (cont.)
Oil ........................................................... 310
Oil Life System........................................ 314
Overheated Protection Operating Mode.... 326
Overheating............................................. 323
Running While Parked............................. 125
Starting.................................................... 113
Entry Lighting.............................................. 164
Event Data Recorders................................. 443
Extender, Safety Belt..................................... 40
Exterior Lamps............................................ 160
F
Filter
Engine Air Cleaner................................... 316
Finish Damage............................................ 393
Flashers, Hazard Warning........................... 152
Flash-to-Pass.............................................. 155
Flat Tire...................................................... 373
Flat Tire, Changing...................................... 374
Flat Tire, Storing......................................... 383Fluid
Power Steering........................................ 332
Windshield Washer.................................. 333
Fog Lamp
Fog .......................................................... 163
Fog Lamp Light........................................... 189
Folding Rear Seat......................................... 15
Fuel............................................................ 298
Additives.................................................. 299
California Fuel.......................................... 299
E85 (85% Ethanol)................................... 300
Filling a Portable Fuel Container.............. 304
Filling Your Tank...................................... 302
Fuels in Foreign Countries....................... 301
Gage....................................................... 190
Gasoline Octane...................................... 298
Gasoline Specications............................ 299
Fuses
Fuses and Circuit Breakers...................... 398
Instrument Panel Fuse Block................... 398
Underhood Fuse Block............................. 400
Windshield Wiper..................................... 397
450

Mirrors
Automatic Dimming Rearview
with OnStar
®........................................ 126
Manual Rearview Mirror........................... 126
Manual Rearview Mirror with OnStar
®...... 126
Outside Convex Mirror............................. 127
Outside Power Mirrors............................. 127
MP3 ............................................................ 236
MyGMLink.com............................................ 429
N
Navigation System, Privacy......................... 444
New Vehicle Break-In.................................. 111
Normal Maintenance Replacement Parts..... 419
O
Odometer.................................................... 176
Off-Road Recovery...................................... 260
Oil
Engine..................................................... 310
Pressure Light.......................................... 188Oil, Engine Oil Life System ......................... 314
Older Children, Restraints............................. 41
Online Owner Center................................... 429
OnStar, Privacy........................................... 444
OnStar
®System, see OnStar®Manual........ 128
Operation, Universal Home
Remote System..............................133, 137
Other Warning Devices................................ 152
Outlet Adjustment........................................ 172
Outlets
Accessory Power..................................... 167
Outside
Convex Mirror.......................................... 127
Power Mirrors.......................................... 127
Overheated Engine Protection
Operating Mode....................................... 326
Owner Checks and Services....................... 414
Owners, Canadian.......................................... 3
454