heater CHEVROLET EXPRESS 1999 User Guide

5-12
If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. If you have an air conditioner and it's on, turn it off.
2. Turn on your heater to full hot at the highest fan
speed and open the window as necessary.
3. If you're in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while
driving
-- DRIVE (D) or THIRD (3).
If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning doesn't come back on, you can
drive normally.
If the warning continues, pull over, stop, and park your
vehicle right away.
If there's still no sign of steam, push down the
accelerator until the engine speed is about twice as fast
as normal idle speed for at least three minutes while
you're parked. If you still have the warning, turn off the
engine and get everyone out of the vehicle until it cools
down. Also, see ªOverheated Engine Protection
Operating Modeº listed previously in this section.
You may decide not to lift the hood but to get service
help right away.
Cooling System (Gasoline Engine)
When you decide it's safe to lift the hood, here's what
you'll see:
A. Radiator Pressure Cap
B. Coolant Recovery Tank
C. Engine Cooling Fan(s)
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 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. 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.
If there seems to be no leak, start the engine again. See if
the engine cooling fan speed increases when idle speed is
doubled by pushing the accelerator pedal down. If it
doesn't, your vehicle needs service. Turn off the engine.
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, start the engine again.
See if the engine cooling fan speed increases when idle
speed is doubled by pushing the accelerator pedal down.
If it doesn't, your vehicle needs service. Turn off
the engine.
How to Add Coolant to the Coolant
Recovery Tank
If you haven't found a problem yet, but the coolant level
isn't at 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 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 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 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.

6-24
A 50/50 mixture of clean, drinkable water and
DEX
-COOL
coolant will:

Give freezing protection down to
-34F (-37C).

Give boiling protection up to 265F (129C).

Protect against rust and corrosion.

Help keep the proper engine temperature.

Let the warning lights and gages work as
they should.
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.
What to Use
Use a mixture of one-half clean, drinkable water and
one
-half DEX-COOL coolant which won't damage
aluminum parts. If you use this coolant mixture, you
don't need to add anything else.
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 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.

6-25
NOTICE:
If you use an improper coolant mixture, your
engine could overheat and be badly damaged.
The repair cost wouldn't be covered by your
warranty. Too much water in the mixture can
freeze and crack the engine, radiator, heater core
and other parts.
If you have to add coolant more than four times a year,
have your dealer check your cooling system.
NOTICE:
If you use the proper coolant, you don't have to
add extra inhibitors or additives which claim to
improve the system. These can be harmful.
Checking Coolant
The coolant recovery tank is located near the center
of the engine compartment. See ªEngine Compartment
Overviewº in the Index for more information
on location.
The vehicle must be on a level surface. When your
engine is cold, the coolant level should be at FULL
COLD, or a little higher.

6-67
NAME CIRCUITS PROTECTED
ETC Electronic Throttle Control
RR BLOWER Rear Auxiliary Blower
Motor Relays
CNG Compressed Natural Gas
ENG
-I Heated O2 Sensors, Mass Air
Flow Sensor, Evap Canister Purge
Valve, Crankshaft Position Sensor,
Secondary Air Injection Relay
(Diesel), Water in Fuel Sensor
(Diesel), Fuel Heater (Diesel),
Glowplug Relay (Diesel),
Wastegate Solenoid (Diesel)
ECM
-I Ignition Coil, Camshaft Position
Sensor, VCM, Fuel Injectors,
Coil Driver
IGN
-E Air Conditioning Clutch Relay
SPARE Spare Fuse
SPARE Spare Fuse
SPARE Spare FuseNAME CIRCUITS PROTECTED
A/C Air Conditioning Clutch Relay
HORN Horn Relay, Underhood Lamp(s)
ECM
-B Fuel Pump Relay, VCM, PCM,
Fuel Pump and Engine Oil
Pressure Switch
SPARE Spare Fuse
SPARE Spare Fuse
AUX A Upfitter Provisions
AUX B Upfitter Provisions
A/C RELAY Air Conditioning
HORN RELAY Horn
A.I.R. RELAY Air
FUEL
PUMP RELAYFuel Pump
STARTER
RELAYStarter
ABS EXPORT
RELAYABS Export

6-70 Wheel Nut Torque
MODEL TORQUE
All
140 lb
-ft (190 N´m)
Cooling System Capacity
ENGINE VIN QTY Without Rear Heater QTY With Rear Heater
ªVORTECº 4300 V6 W 11.0 quarts (10.4 L) 14.0 quarts (13.2 L)
ªVORTECº 5000 V8 M 17.0 quarts (16.0 L) 20.0 quarts (18.9 L)
ªVORTECº 5700 V8 R 17.0 quarts (16.0 L) 20.0 quarts (18.9 L)
ªVORTECº 8100 V8 G 23.0 quarts (21.8 L) 26.0 quarts (24.6 L)
After refill, the level MUST be checked as outlined under ªEngine Cooling Systemº in Section 5.
Engine Oil Capacity
ENGINE VIN Quantity
ªVORTECº 4300 V6 W 4.5 quarts (4.3 L)
ªVORTECº 5000 V8 M 5.0 quarts (4.8 L)
ªVORTECº 5700 V8 R 5.0 quarts (4.8 L)
ªVORTECº 8100 V8 G 6.5 quarts (6.15 L)