2001 Oldsmobile Silhouette radiator

5-12
Cooling System
When you decide it's safe to lift the hood, here's what
you'll see:
A. Radiator Pressure Cap
B. Electric Engine Cooling Fans
C. Coolant Recovery Tank
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 recovery tank is boiling,
don't do anything else until it cools down.

5-13
When the engine is cold, the coolant level should be at
or above the FULL COLD mark. If it isn't, you may
have a leak 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. Don't touch them. If you do, you
can be burned.
Don't 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:
Engine damage from running your engine
without coolant isn't covered by your warranty.
See ªOverheated Engine Protection Operating
Modeº in the Index.

5-14
NOTICE:
When adding coolant, it is important that you
use only DEX
-COOL
(silicate-free) coolant.
If coolant other than DEX-COOL is added to
the system, premature engine, heater core or
radiator corrosion may result. In addition, the
engine coolant will require change sooner
-- at
30,000 miles (50 000 km) or 24 months,
whichever occurs first. Damage caused by the
use of coolant other than DEX
-COOL
is not
covered by your new vehicle warranty.
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, both fans should
be running. If they aren't, your vehicle needs service.
How to Add Coolant to the Coolant
Recovery Tank
If you haven't found a problem yet, but the coolant level
isn't at or above the FULL COLD mark, add a 50/50
mixture of clean, drinkable water and DEX
-COOL

engine coolant at the coolant recovery tank. See ªEngine
Coolantº in the Index for more information.
CAUTION:
Adding only plain water to your cooling system
can be dangerous. Plain water, or some other
liquid like 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 wouldn't
get the overheat warning. Your engine could
catch fire and you or others could be burned.
Use a 50/50 mixture of clean, drinkable water
and DEX
-COOL
coolant.

5-15
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. Don't spill coolant on a hot engine.
When the coolant in the coolant recovery tank is at or
above the FULL COLD mark, start your vehicle.
If the overheat warning continues, there's one more
thing you can try. You can add the proper coolant
mixture directly to the radiator, but be sure the cooling
system is cool before you do it.

5-16
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 the radiator pressure cap to cool if you ever
have to turn the pressure cap.

5-17 How to Add Coolant to the Radiator
1. You can remove the radiator pressure cap when
the cooling system, including the radiator pressure
cap and upper radiator hose, is no longer hot.
Turn the pressure cap slowly counterclockwise until
it first stops. (Don't press down while turning the
pressure cap.)
If you hear a hiss, wait for that to stop.
A hiss means there is still some pressure left.
2. Then keep turning the pressure cap, but now push
down as you turn it. Remove the pressure cap.
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. Don't spill coolant on a hot engine.

5-18
Bypass Tube Housing
3. After the engine cools, open the coolant air bleed valves.
There are two bleed valves. One is located on the
thermostat housing. The other is located on the
thermostat bypass tube.
4. Fill the radiator with the proper DEX-COOL

coolant mixture, up to the base of the filler neck.
See ªEngine Coolantº in the Index for more
information about the proper coolant mixture.
If you see a stream of coolant coming from an air
bleed valve, close the valve. Otherwise, close the
valves after the radiator is filled.
5. Rinse or wipe any spilled coolant from the engine
and the compartment.

5-19
6. Start the engine and let it run until you can feel the
upper radiator hose getting hot. Watch out for the
engine cooling fans.
7. By this time, the coolant level inside the radiator
filler neck may be lower. If the level is lower, add
more of the proper DEX
-COOL
coolant mixture
through the filler neck until the level reaches the
base of the filler neck.
8. Then replace the pressure cap. At any time during
this procedure if coolant begins to flow out of the
filler neck, reinstall the pressure cap. Be sure the
arrows on the pressure cap line up like this.