2020 CHEVROLET LOW CAB FORWARD engine overheat

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
246 Vehicle Care
{Warning
For storage, close the cap of
coolant container securely and
keep it in a place inaccessible to
children.
You and others could be seriously
injured.
Using any coolant other than that
recommended by your dealer could
cause damage to the engine,
radiator or heater core. In particular,
use of coolants containing borate
salts or silicates may result in
engine or radiator corrosion,
causing engine coolant leaks and
other problems.
To dilute the coolant, use distilled
water or deionized water.
Do not use the coolant at any
coolant concentration other than
that specified. If the coolant
concentration is 60% or higher,
overheating is likely to occur, while
if it is 30% or lower, anti-corrosion
function is not provided sufficiently. Using coolant at any coolant
concentration other than that
specified may reduce anti-freezing
performance, and engine coolant
may freeze.
If the engine coolant decreases
rapidly, stop the vehicle in a safe
place and contact your dealer for
advice and repair.
Checking the Engine Coolant
Level
For the single cab model, the
engine coolant reserve tank is
located behind the front-right wheel.
See
Cab Tilting 0233.
For the crew cab model, the engine
coolant reserve tank is under the
access panel beneath the left rear
seat. See Engine Cover 0235.
When the engine has cooled down,
make sure that the fluid level in the
engine coolant reserve tank is no
lower than the “MIN”line. In
addition, carefully remove the
radiator cap and check to see if it is
damaged. Check that the engine
coolant is full to the filler neck.
Check the engine coolant level only
when it is cold.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
248 Vehicle Care
1. When the engine is cool,remove the radiator cap (1).
.Turn the cap slowly to the
left until it reaches a “stop”.
Do not press down while
turning the cap.
. Wait until any remaining
pressure (indicated by a
hissing sound) is relieved,
then press down on the cap
and continue turning it to
the left.
2. Fill the radiator to the base of the filler neck (2) and install the
radiator cap. Add enough engine coolant to provide for
required cooling, freezing, and
corrosion protection.
3. Run the engine until the engine coolant temperature rises to
normal level, and idle the
engine for 10 minutes.
4. Install the radiator cap.
Check, replenish or change the
engine coolant only after the engine
has sufficiently cooled down.
When the engine is still hot, take
care to prevent engine coolant from
contact with the exhaust manifold.
Any such contact could result in
exhaust manifold damage.
If you use the proper quality engine
coolant, there is no need to add
extra inhibitors or additives which
claim to improve the system. They
may be harmful to the proper
operation of the system.
Do not overfill the engine coolant
reserve tank.
If the level of engine coolant
changes rapidly, have your vehicle
inspected at your dealer. Thermostat
The engine coolant temperature is
controlled by thermostat(s). The
thermostats stop engine coolant
flow through the radiator until a
preset temperature is reached. The
thermostats are installed in the
engine coolant outlet on the engine
block. The same thermostats are
used in both winter and summer.
When a replacement is needed,
genuine GM parts are
recommended.
Radiator Pressure Cap
The radiator cap, a 108 kPa (16 psi)
pressure type, must be installed
tightly, otherwise engine coolant
may be lost and damage to the
engine may result from overheating.
The radiator pressure cap should be
checked periodically for proper
operation. If a replacement is
required, a genuine GM part is
recommended.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Vehicle Care 249
Engine Overheating
When the Engine Overheats
The engine cooling system may
overheat if the engine coolant level
is too low, if there is a sudden loss
of engine coolant (such as radiator
hose failure), or if other problems
occur. It may also temporarily
overheat during severe operating
conditions such as:
.Climbing a long hill on a hot day.
. Stopping after high-speed
driving.
. Idling for long periods in traffic.
If engine power drops and the
needle on the engine coolant
temperature gauge goes up above
the upper limit of the safety zone
and enters the "H" zone, the engine
is overheating. The engine overheat
warning light will come on and the
warning buzzer will sound. Either
steam or boiling engine coolant will
squirt out of the radiator. The
vehicle will also have an “OVERHEAT”
message displayed. Take the
following corrective actions
immediately.{Warning
To help avoid being burned:
Do not tilt the cab or open the
engine access cover if you see or
hear steam or engine coolant
escaping from the engine
compartment. Wait until no steam
or engine coolant can be seen or
heard before tilting the cab or
opening the engine cover.
Do not remove the radiator cap or
engine coolant reserve tank cap if
the engine coolant in the tank is
boiling. Also do not remove the
radiator cap while the engine and
radiator are still hot. Scalding fluid
and steam can be blown out
under pressure if either cap is
taken off too soon.
You and others could be seriously
injured. If Steam Is Coming from the
Engine Compartment
{Warning
If the engine coolant temperature
gauge shows an overheat
condition or you have other
reasons to suspect the engine
may be overheating, continued
operation of the engine (other
than as described here) even for
a short period of time may cause
a fire and the result in personal
injury and severe vehicle
damage. Take immediate action
as outlined.
You and others could be seriously
injured.
If you see or hear escaping steam
or have any other reason to suspect
there is a serious overheat
condition, stop and park the vehicle
as soon as it is safe to do so, turn
on the hazard warning flasher and
then turn off the engine immediately
and safely exit the vehicle.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
250 Vehicle Care
If Steam Is Not Coming from the
Engine CompartmentIf the engine coolant temperature
gauge shows an overheat condition,
or you have reason to suspect the
engine may be overheating, take
the following steps:1. Operate the hazard warning flasher and pull the vehicle
immediately over to a safe
place that does not impede
traffic and park it.
2. Idle the engine and wait until the engine coolant temperature
drops to safety zone. If your air
conditioner (if equipped) is on,
turn it off. And turn on the
heater to help the engine
expel heat.
3. When the needle of the engine coolant temperature gauge
returns to the middle of the
safety zone, stop the engine.
If the needle of engine coolant
temperature gauge does not
drop inside into the safety
zone, turn the engine off and
have your vehicle serviced at
the nearest dealer. When the cooling fan for the
radiator is not turning, turn off
the engine immediately.
{Warning
Even when the engine has been
stopped, the engine coolant in the
radiator remains under pressure.
Immediately removing the radiator
cap could cause steam or hot
water to blow out, and you could
be scalded as a result. The
engine coolant in the reserve tank
may also be hot. Immediately
removing the cap could cause hot
water to blow out, and possibly
scald you. Perform inspection,
refilling, and replacement of
coolant only when its temperature
has cooled.
When removing the radiator cap
and reserve tank cap, use a thick
cloth to cover the cap and turn it
little by little.
You and others could be seriously
injured.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Vehicle Care 251
4. If no steam or engine coolantcan be seen or heard from the
engine compartment:
.Tilt the cab or open the
engine access cover.
‐If the engine coolant is
boiling, wait until it stops
before proceeding.
‐ Look at the see-through
reserve tank. The
engine coolant level
should be between the
"MAX" and "MIN" lines
on the reserve tank.
‐ If necessary, pour
engine coolant (See
Engine Coolant 0243
for the proper coolant
and water mixture) into
the reserve tank only,
not directly into the
radiator. Also, do not
check engine coolant
level at the radiator.
. Make sure the fan belts are
not broken, or off the
pulleys, and that the fan
turns when the engine is started. Make sure the fan
blade and pulleys are not
broken.
. Check the radiator hoses
and connections, heater
hoses and connections,
radiator, water pump, EGR
cooler, and SCR system
and hoses for leakage.
If you do not find a leak or
other problem, carefully add
engine coolant to the
reserve tank.
If the engine coolant level in
the reserve tank is at the
correct level but there is still
an indication on the
instrument panel of an
overheat condition:
You must let the engine
cool first. You may then add
engine coolant directly to
the radiator. See “Adding
Engine Coolant” under
Engine Coolant 0243.
5. Inspect to see if there is any dirt, etc. attached to the front
surface of the radiator. Also, inspect to see if there is
anything blocking the core.
If there is anything attached,
clean and remove it.
6. After the inspection, regardless of the vehicle condition, please
contact the nearest dealer.
Once the engine coolant
temperature gauge no longer
signals an overheat condition, you
can resume driving at a reduced
speed. Return to normal driving
after about 10 minutes if the gauge
pointer does not again show an
overheat condition.
When tap water only has been used
for engine coolant in an emergency,
change the engine coolant as soon
as possible.
Engine damage may be caused if
an overheating engine is suddenly
refilled with water. Instead, refill
slowly.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
286 Vehicle Care
rims, refer to the“Tire and Rim
Association Inc. Yearbook”, or your
tire dealer.
Tire Inflation
{Warning
To reduce the risk of loss of
vehicle control and personal
injury:
Tires must be properly inflated,
and your vehicle must not be
overloaded (see the information
on Information on Loading the
Vehicle 046 and "Tire Load and
Inflation Table" under Tire
Pressure 0297).
Be sure to keep tires properly
inflated. A tire that is run while
seriously underinflated may
overheat to the point where the
tire may lose air suddenly and/or
catch fire, possibly resulting in
personal injury and/or property
damage. See
“Tire Load and Inflation Table”
under Tire Pressure 0297.
In no case should the front or rear
tire load exceed the maximum
recommended gross axle weight
rating (front GAWR or rear GAWR).
The efficiency of the vehicle will be
upset if air pressure in the tires are
not equal. Balanced inflation results
when the tires on the same axle
carry the same air pressure.
A difference in pressure between
the front and rear tires may be
permissible within certain limitations,
however, there should not be a
difference in pressures between the
right and left tires on the same axle.
Always use a truck tire pressure
gauge (a pocket-type gauge is not
advised) when checking inflation
pressures. Visual inspection of tires
for inflation pressures is not enough,
especially in the case of radial tires.
Underinflated radial tires may look
similar to correctly inflated radial
tires. If the inflation pressure on a
tire is found to be low frequently,
have your dealer correct the cause. Be sure to install the tire inflation
valve caps to prevent dirt and
moisture from getting into the valve
core, which could cause air leakage.
An underinflated tire in a dual wheel
assembly is harder to notice than
one in a single wheel assembly. The
properly inflated dual tire carries its
own load plus that of the
underinflated tire. Both tires can
overheat, which may result in
property damage and/or personal
injury (see previous WARNING).
Tires Used or Stored for a Long
Period of Time
Tires are a rubber product and
degrade over time, even if they are
not being used. If any of your tires is
5 to 7 years old or more, please
have them inspected for safe
driving. For further information,
please check with the tire
manufacturer.
Dual Tire Operation
The outer tire of a pair on dual
wheel installations generally wears
faster than the inner tire. If this

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Technical Data 355
Engine Drive Belt Routing
Fan Belt and Air Conditioning
Compressor Belt
See theMaintenance Schedule
0 317.
No. Name
1 Fan belt
2 Fan pulley
3 A/C belt
4 A/C compressor
5 Tension pulley
6 Crank pulley No.
Name
7 Alternator
If your air conditioning system is
functioning properly, it is not
necessary to remove and replace
the refrigerant or compressor oil.
. A V-ribbed belt is used for the
fan belt. This type of belt
requires the tension to be
adjusted more accurately than is
required with the conventional V
belt. Inappropriate tension could
cause the belt to make noise or
break. When the fan belt is
damaged, electricity is not
properly generated or becomes
a cause of engine overheating.
You must check the tension of
the fan belt carefully.
. Use dealer-certified genuine
parts when changing the
fan belt.
. Have the vehicle inspected and
serviced at your dealer. .
The air conditioning drive belt,
if equipped, must be adjusted
after fan belt adjustment. If the
belt is not adjusted properly, the
A/C belt may experience
excessive tension, and possible
premature failure.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Index 367
D
Damage Repair, Collision . . . . . . . 359
Danger, Warning, and Caution . . . . 3
Daytime Running Lamps (DRL)Indicator Light . . . . . . . . . . . . . . . . . . 69
Devices Auxiliary . . . . . . . . . . . . . . . . . . . . . . 107
Diesel Engine Engine Alarm andAutomatic Shutdown . . . . . . . . 164
Diesel Exhaust Fluid . . . . . . . . . . . . 180
Diesel Exhaust Fluid (DEF) Gauge . . . . . . . . . . . . . . . . . . . . . . . . . 60
Diesel Exhaust Fluid (DEF)
Warning Light . . . . . . . . . . . . . . . . . . 68
Diesel Particulate Filter . . . . . . . . . 171
Distracted Driving . . . . . . . . . . . . . . . 130
Dome Lamps . . . . . . . . . . . . . . . . . . . . 84
Door Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Power Locks . . . . . . . . . . . . . . . . . . . . 21
Drive Belt Routing, Engine . . . . . . 355
Driver Behavior . . . . . . . . . . . . . . . . . 129
Driver Information Center (DIC) . . . . . . . . . . . . . . . . . . . 70
Driving Better Fuel Economy . . . . . . . . . 129
Emergencies . . . . . . . . . . . . 145, 155 Driving (cont'd)
Hill and Mountain Roads . . . . . . 141
If the Vehicle is Stuck . . . . . . . . . 144
Wet Roads . . . . . . . . . . . . . . . . . . . 140
Winter . . . . . . . . . . . . . . . . . . . . . . . . 142
E
Electrical Equipment,
Add-On . . . . . . . . . . . . . . . . . . . . . . . 227
Electrical System
Overload . . . . . . . . . . . . . . . . . . . . . 277
Emergencies . . . . . . . . . . . . . . 145, 155
Engine Air Cleaner/Filter . . . . . . . . . . . . . 243
Alarm and Automatic
Shutdown . . . . . . . . . . . . . . . . . . . 164
Check Light (Malfunction Indicator) . . . . . . . . . . . . . . . . . . . . . . 61
Checks Before Operating . . . . . 166
Compartment Overview . . . . . . . 234
Coolant . . . . . . . . . . . . . . . . . . . . . . . 243
Coolant Temperature Gauge . . . . 60
Cover . . . . . . . . . . . . . . . . . . . . . . . . . 235
Drive Belt Routing . . . . . . . . . . . . 355
Exhaust . . . . . . . . . . . . . . . . . . . . . . 168
Heater . . . . . . . . . . . . . . . . . . . . . . . . 163
High Idle System . . . . . . . . . . . . . 165
Oil Pressure Light . . . . . . . . . . . . . . 67 Engine (cont'd)
Overheating . . . . . . . . . . . . . . . . . . 249
Reduced Power Light . . . . . . . . . . . 69
Running While Parked . . . . . . . . 170
Shutdown Warning Light . . . . . . . . 68
Engine Oil Level Indicator Light . . . . . . . . . . . . 67
Engines Diesel Fuel . . . . . . . . . . . . . . . . . . . 218
Exhaust Brake . . . . . . . . . . . . . . . . . . 213
Exhaust Brake Light . . . . . . . . . . . . . 65
Exhaust Fluid Diesel . . . . . . . . . . . . . . . . . . . . . . . . 180
Extender, Seat Belt . . . . . . . . . . . . . . 37
Exterior Lamp Controls . . . . . . . . . . 80
F
Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . 260
Filter, Engine Air Cleaner . . . . . . . . . . . 243
Fixed Mast Antenna . . . . . . . . . . . . . 90
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . 81
Flashers, Hazard Warning . . . . . . . 82
Flat Tire . . . . . . . . . . . . . . . . . . . . . . . . 300
Fluid Automatic Transmission . . . . . . 241
Brakes . . . . . . . . . . . . . . . . . . . . . . . . 258