radiator CHEVROLET DYNASTY 1993 Service Manual

ENGINE COOLING SYSTEM
WARNINGS AND PRECAUTIONS
WARNING: ANTIFREEZE IS AN ETHYLENE GLYCOL
BASE COOLANT AND IS HARMFUL IF SWAL-
LOWED OR INHALED. IF SWALLOWED, DRINK
TWO GLASSES OF WATER AND INDUCE VOMIT-
ING. IF INHALED, MOVE TO FRESH AIR AREA.
SEEK MEDICAL ATTENTION IMMEDIATELY. DO
NOT STORE IN OPEN OR UNMARKED CONTAIN-
ERS. WASH SKIN AND CLOTHING THOROUGHLY
AFTER COMING IN CONTACT WITH ETHYLENE
GLYCOL. KEEP OUT OF REACH OF CHILDREN. DISPOSE OF GLYCOL BASE COOLANT PROP-
ERLY, CONTACT YOUR DEALER OR GOVERNMENT
AGENCY FOR LOCATION OF COLLECTION CEN-
TER IN YOUR AREA. DO NOT OPEN A COOLING SYSTEM WHEN THE
ENGINE IS AT RUNNING TEMPERATURE, PER-
SONAL INJURY CAN RESULT. AVOID RADIATOR COOLING FAN WHEN ENGINE
COMPARTMENT RELATED SERVICE IS PER-
FORMED, PERSONAL INJURY CAN RESULT.
CAUTION: Do not use straight antifreeze as engine
coolant, inadequate engine running temperatures
can result. Do not operate vehicle without proper concentra-
tion of recommended ethylene glycol coolant, high
running temperatures and cooling system corrosion
can result.
The engine cooling system will develop internal
pressure of 97 to 123 kPa (14 to 18 psi) at normal op-
erating temperature. Allow the vehicle approxi-
mately one half hour to cool off before opening the
cooling system. As an indicator of pressure, squeeze
the upper radiator hose between index finger and
thumb. If it collapses with little effort the system
would have low internal pressure and should be safe
to open to the first safety notch of the radiator cap.
Refer to Group 7, Cooling System.
COOLING SYSTEM INSPECTION
Coolant level (Fig. 5) should be inspected when
other engine compartment service is performed or
when coolant leak is suspected. Coolant recovery
tank level should read between the MIN and MAX
marks, located on the side of recovery tank, when the
engine is at normal operating temperature. Normal
coolant level maintenance does not require the re-
moval of radiator cap. Cooling system freeze protec-
tion should be tested at the onset of the winter
season or every 12 months. Service is required if
coolant is low, contaminated, rusty or freeze protec-
tion is inadequate. To properly test cooling system,
see Group 7, Cooling System.
The cooling system factory fill is a mixture of 50%
Glycol based antifreeze and 50% water. Using a suit-
able hydrometer, measure antifreeze concentration in
the radiator when the engine is cool. If the cooling
system has recently been serviced, allow coolant to
circulate for at least 20 minutes before taking hy-
drometer reading. Properly mixed coolant will pro-
tect the cooling system to -37ÉC (-35ÉF). If the freeze
protection is above -28ÉC (-20ÉF), drain enough cool-
ant from the cooling system to allow room to add an-
Fig. 3 Remove Oil Filter
Fig. 4 Install Oil Filter
Fig. 5 Coolant Recovery Tank
0 - 10 LUBRICATION AND MAINTENANCE Ä

tifreeze to achieve adequate protection. A mix table
on the coolant container indicates the amount of an-
tifreeze required to winterize the cooling system
based on the capacity, see Capacity Chart in General
Information section of this group.
SELECTING ANTIFREEZE
Chrysler Corporation recommends Mopar Anti-
freeze/Summer Coolant, or equivalent be used to win-
terize and protect cooling system.
RADIATOR CAP
The radiator cap must be secure to provide proper
pressure release and coolant recovery. Inspect and
test radiator cap when cooling system service is per-
formed or when problem is suspected.
COOLING SYSTEM SERVICE
The cooling system should be drained, flushed and
filled with the proper coolant mixture at the inter-
vals described in the Lubrication and Maintenance
Schedules. Refer to General Information section of
this group. For proper service instructions see Group
7, Cooling System.
ENGINE AIR CLEANER
The engine air cleaner should be serviced at the in-
tervals described in the Lubrication and Mainte-
nance Schedules. Refer to General Information
section of this group. Additional information can be
found in Group 14, Fuel System and Group 25, Emis-
sion System. Inspect all air cleaner hoses or tubes for
damage or leaks when other engine compartment
service is performed. Replace faulty components.
AIR CLEANER SERVICE
CAUTION: The air cleaner cover must be installed
properly for the emissions system and engine con-
troller to function correctly. Do not immerse paper air filter element or temper-
ature sensor in cleaning solvents, damage can re-
sult.
TO SERVICE AIR CLEANER ASSEMBLY: (1) Raise hood of vehicle and inspect all air cleaner
components for damage or improper attachment. (2) Remove air cleaner cover (Fig. 6, 7, 8, 9, or 10).
(3) Remove paper air filter element from air
cleaner body. Hold a shop light on throttle body side
of element. Inspect air intake side of element. If light
is visible through element, blow dust from element
(Fig. 11) and reuse. If element is saturated with oil
or light is not visible, replace filter. If element is sat-
urated with oil, perform crankcase ventilation sys-
tem tests. (4) Remove fiber crankcase filter (Fig. 6, 7, 8, 9, or
10) and clean with solvent, squeeze filter dry and ap- ply small amount of engine oil. If a metallic mesh is
used to retain fiber filter, clean mesh with solvent
and reuse.
(5) Clean inside of air cleaner cover and body with
vacuum or compressed air. If oily, wash with solvent. To Install, reverse the preceding operation.
Fig. 6 Air CleanerÐ3.0L Engine
Fig. 7 Air CleanerÐFlexible Fuel Engine
Fig. 8 Air CleanerÐ16 Valve Engine
Ä LUBRICATION AND MAINTENANCE 0 - 11

(6) Repeat steps 2 through 5 until a clear air free
flow of brake fluid is coming out of the Primary Ac-
cumulator bleeder screw. (7) Next select and actuate the RF Build/Decay
Valve. Again repeat steps 2 through 5 until a clean
air free flow of brake fluid is coming out of the Pri-
mary Accumulator bleeder screw.
4 SECONDARY ACCUMULATOR (1) Put a bleeder tube on the Secondary Accumu-
lator bleeder screw. (Fig. 1) (2) Use a pressure bleeder, or have an assistant,
apply light and constant pressure on the brake pedal.
Loosen the Secondary Accumulator bleeder screw
(Fig. 1). (3) Using the DRB II select the Actuate Valves
test mode. Then actuate the LF/RR Isolation Valve. (4) Bleed the Secondary Accumulator. Until a clear
air free flow of brake fluid is evident in the clear
hose and no air bubbles appear in the container, or
the brake pedal bottoms. (5) Tighten the bleeder screw and release the
brake pedal. (6) Repeat steps 2 through 5 until a clear air free
flow of brake fluid is coming out of the Secondary
Accumulator bleeder screw. (7) Next select and actuate the LF Build/Decay
Valve. Again repeat steps 2 through 5 until a clean
air free flow of brake fluid is coming out of the Pri-
mary Accumulator bleeder screw.PUMP/MOTOR SERVICE
On the Bendix Anti-Lock 6 Brake System the
Pump/Motor assembly can only be serviced as part of
Modulator Assembly.
MODULATOR ASSEMBLY (FIG. 2)
REMOVAL
(1) Center vehicle on hoist, or raise front of vehicle
on jack stands. (2) Disconnect and remove the battery, battery
tray and acid shield covering the modulator assembly
(Fig. 2). (3) Disconnect the delta (P) switch electrical con-
nector from the Modulator Assembly (Fig. 3). Re-
move the top Modulator Assembly bracket to fender
shield mounting bolt (Fig. 2). (4) Disconnect the 2 master cylinder supply tubes
at the Modulator Assembly. Loosen the 2 tubes at
the Master Cylinder so the tubes can be swung out of
the way without kinking them (Fig. 4) (5) Raise the vehicle on the hoist.
(6) From under the vehicle disconnect the Modula-
tor Assembly 10 way connector (Fig. 3). Remove the
4 remaining hydraulic brake tubes from the Modula-
tor Assembly. (7) Remove Modulator Assembly bracket mounting
bolt closest to junction block. (8) Loosen but do not fully remove bracket mount-
ing bolt nearest the radiator. (9) Lower the vehicle, the Modulator Assembly and
bracket can now be lifted out of the vehicle (Fig. 1)
Fig. 2 Modulator Assembly
5 - 128 ANTI-LOCK 6 BRAKE SYSTEM Ä

COOLING SYSTEM
CONTENTS
page page
ACCESSORY DRIVE BELTS ............... 24
ENGINE BLOCK HEATER ................. 28
GENERAL INFORMATION .................. 1 SERVICE PROCEDURES
.................. 10
SPECIFICATIONS ....................... 29
GENERAL INFORMATION
Throughout this group, references may be made to
a particular vehicle by letter or number designation.
A chart showing the breakdown of these designations
is included in the Introduction Section at the front of
this service manual.
COOLING SYSTEM
The cooling system consists of an engine cooling
module, thermostat, coolant, a water pump to circu-
late the coolant. The engine cooling module may con-
sist of a radiator, electric fan motor, shroud, radiator
pressure cap, coolant reserve system, transmission oil
cooler, hoses, clamps, air condition condenser, trans-
mission oil lines and charge air cooler.
² When Engine is cold: Thermostat is closed, cooling
system has no flow through the radiator. The coolant
bypass flows through the engine only. ²
When Engine is warm: Thermostat is open, cooling
system has bypass flow and coolant flow through ra-
diator. Its primary purpose is to maintain engine temper-
ature in a range that will provide satisfactory engine
performance and emission levels under all expected
driving conditions. It also provides hot water (cool-
ant) for heater performance and cooling for auto-
matic transmission oil. It does this by transferring
heat from engine metal to coolant, moving this
heated coolant to the radiator, and then transferring
this heat to the ambient air. Coolant flow circuits for 2.2L and 2.5L engine
equipped vehicles are shown in (Fig 1). Turbocharged
equipped engines coolant routing and plumbing are
shown in (Fig 2). The 3.0L engine coolant routing is
shown in (Fig 3). The 3.3L and 3.8L engine coolant
routing is shown in (Fig 5).
Fig. 1 Cooling System OperationÐ2.2/2.5L Engines
Ä COOLING SYSTEM 7 - 1

TURBOCHARGER COOLANT ROUTING
Engines equipped with a Turbocharger maintain a
continuous engine coolant flow through the Turbo-
charger bearing housing water jacket. Hose and tube
assemblies provide a closed loop coolant flow from
the cylinder block water jacket to the turbocharger
housing and back to the cylinder head waterbox (Fig.
2). Excluding heated intake manifold hose routing
(hose is routed from waterbox directly to heater), all
other system functions are essentially the same as
shown for standard engines. During any reassembly procedures all pipe fittings
in water jacket, bearing housing and waterbox re-
quire cleaning and application of thread sealant for
entire length of threads. Tighten all fittings to
torque specified in (Fig 2).
WATER PIPESÐ3.0L
The 3.0L engines use metal piping beyond the
lower radiator hose to route coolant to the suction
side of water pump, located in the V of the cylinder
banks. These pipes are also provided with inlet nipples for
thermostat bypass and heater return coolant hos-
es,and brackets for rigid engine attachment. The
pipes employ O-rings for sealing at their interconnec-
tion and to the water pump (Fig. 4).
Fig. 2 Turbocharger-Tube Hose AssembliesÐTurbo III Engine
Fig. 3 Cooling System OperationÐ3.0L Engine
7 - 2 COOLING SYSTEM Ä

SERVICE PROCEDURES INDEX
page page
Automatic Transmission Oil Coolers .......... 23
Coolant ................................ 14
Coolant Recovery System (CRS) ............. 17
Cooling System Drain, Clean, Flush and Refill . . 15
Electric Fan Motor ........................ 22
Engine Thermostats ....................... 13
Fan Shroud ............................. 23 Fans
.................................. 21
Radiator Hoses .......................... 21
Radiator Pressure Cap .................... 18
Radiators ............................... 18
Testing System for Leaks .................. 17
Water Pumps ........................... 10
WATER PUMPS
A quick test to tell whether or not the pump is
working is to see if the heater warms properly. A
defective pump will not be able to circulate heated
coolant through the long heater hose. The water pump on all models can be replaced
without discharging the air conditioning system.
WATER PUMPÐ2.2/2.5L ENGINE
The 2.2/2.5L engine water pump has a diecast alu-
minum body and housing with a stamped steel impel-
ler. The 2.2/2.5L pump uses an O-ring gasket between
body and housing. The assembly bolts directly to the
block. Cylinder block to water pump sealing is provided
by a rubber O-ring.
REMOVAL (1) Drain cooling system. Refer to Draining Cooling
System in this group. (2) If equipped with air conditioning, see Solid
Mount Accessory Bracket in (Standard Service Proce-
dures) Group 9, Engine: (a) Remove air conditioning compressor and gen-
erator from solid mount bracket and set aside.It is
not necessary to discharge the a/c system. (b) Remove solid mount bracket.
(3) If the vehicle is not equipped with air condi-
tioning, remove generator and mounting bracket. (4) Disconnect lower radiator and heater hoses
from pump. (5) Remove water pump attaching screws to engine
(Fig. 1). Turbo III has a spacer between the water
pump and block on the lower screw.
DISASSEMBLY (1) Remove three screws holding pulley to water
pump. (2) Remove nine screws holding water pump body
to housing. Remove the pump body from housing
(Fig. 2). (3) Clean gasket surfaces on water pump housing
and engine block. (4) Remove and discard O-ring gaskets and clean
O-ring grooves.
Fig. 2 Water Pump ComponentsÐ2.2/2.5L
Fig. 1 Water PumpÐ2.2/2.5L Engines
7 - 10 COOLING SYSTEM Ä

INSPECTION Replace water pump body assembly if it has any of
these defects: (1) Cracks or damage on the body.
(2) Water leaks from the shaft seal, evident by
coolant traces below the vent hole. (3) Loose or rough turning bearing.
(4) Impeller rubs either the pump body or the hous-
ing.
ASSEMBLY
Body assembly and housing are serviced as separate
components. (1) Install new O-ring gasket in body O-ring groove.
(2) Assemble pump body to housing and tighten nine
screws to 12 N Im (105 in. lbs.) (Fig. 2).
(3) Rotate pump by hand to check for freedom of
movement. (4) Position water pump pulley to water pump.In-
stall three screws and tighten to 30 N Im (250 in. lbs.).
(5) Position new O-ring in housing to block O-ring
groove.
INSTALLATION (1) On Turbo III engines install the coolant deflector
into the block before installing pump on engine (Fig. 3).
Install spacer between the pump and block for
Turbo III only before tightening pump to speci-
fications. Tighten three top screws (Fig. 1) to 28 N Im
(250 in. lbs.) and lower screw to 68 N Im (50 ft. lbs.).
(2) Install bypass/heater hose and lower radiator
hose. (3) Install generator and air conditioning compres-
sor bracket(s). For solid mount bracket see standard
service procedures in Group 9 Engine. (4) Install generator and air conditioning compres-
sor. (5) Refill cooling system. See
Refilling Cooling
System. (6) Install drive belt, See Accessory Drive Belts,
this Group.
WATER PUMPÐ3.0L ENGINE
The 3.0L pump bolts directly to the engine block,
using a gasket for pump to block sealing (Fig. 4). The
pump is serviced as a unit. The water pump is driven by the timing belt. See
Timing System in Group 9, Engine for component re-
moval providing access to water pump.
REMOVAL (1) Drain cooling system. Refer to Draining Cool-
ing System in this group. (2) Remove mounting bolts.
(3) Separate pump from water inlet pipe (Figs. 4
and 5) and remove.
INSPECTION Replace the water pump if it has any of the follow-
ing defects.
Fig. 4 Water PumpÐ3.0L Engine
Fig. 5 Water Pump Inspection
Fig. 3 Coolant DeflectorÐTurbo III
Ä COOLING SYSTEM 7 - 11

(5) Install drive belt. See Accessory Drive Belts
this group. (6) Install right front lower fender shield.
(7) Refill Cooling System. See Refilling Cooling
System in this section.
ENGINE THERMOSTATS
The 2.2 and 2.5L engine thermostats are located on
the front of the engine (radiator side) in the water
box which is part of the cylinder head construction
(Fig. 9). Turbo III thermostat is located in the water
box located on the driver side of the cylinder head
(Fig. 10). These thermostats do not have an air bleed notch.
The 3.0L engine thermostat is located in a water
box, formed in the timing belt end of the intake man-
ifold. This thermostat has an air bleed valve, located
in the thermostat flange (Fig. 11). The 3.3/3.8L engine thermostat is located in a wa-
ter box, formed in the drive belt side of the intake
manifold (Fig. 13).
DESCRIPTION AND OPERATION
The engine cooling thermostats are wax pellet
driven, reverse poppet choke type. They are designed
to provide the fastest warm up possible by prevent-
ing leakage through them and to guarantee a mini-
mum engine operating temperature of 88 to 93ÉC
(192 to 199ÉF). They also automatically reach wide
open so they do not restrict flow to the radiator as
temperature of the coolant rises in hot weather to
around 104ÉC (220ÉF). Above this temperature the
coolant temperature is controlled by the radiator,
fan, and ambient temperature, not the thermostat.
OPERATION AND TESTING
The thermostat is operated by a wax filled con-
tainer (pellet) which is sealed so that when heated to
a predetermined temperature. The wax expands
enough to overcome the closing spring and water
pump pressure, which forces the valve to open. Cool-
ant leakage into the pellet will cause a thermostat to
fail open. Do not attempt to free up a thermostat
with a screwdriver. The open too soon type failure mode is included in
the onboard diagnosis. The check engine light will
not be lit by an open too soon condition. If it has
failed open, code 17 will be set. Do not change a ther-
mostat for lack of heat by gauge or heater perfor-
mance, unless code 17 is present, see diagnosis for
other probable causes. Failing shut is the normal
long term mode of failure, and normally, only on
high mileage vehicles. The temperature gauge will
indicate this, Refer to diagnosis in this section.
REMOVAL
(1) Drain cooling system down to thermostat level
or below. (2) Remove thermostat housing bolts and housing
(Figs. 9, 10, 11 and 13). (3) Remove thermostat, discard gasket and clean
both gasket sealing surfaces.
INSTALLATIONÐ2.2/2.5L AND TURBO III ENGINES
Place a new gasket (dipped in clean water) on wa-
ter box surface, center thermostat in water box on
gasket. Place housing over gasket and thermostat,
making sure thermostat is in the thermostat hous-
ing. Bolt housing to water box (Figs. 9 and 10).
Tighten bolts to 28 N Im (250 in. lbs.). Refill cooling
system (see Refilling System ).
INSTALLATIONÐ3.0L ENGINE
Center thermostat in water box pocket. Check that
the flange is seated correctly in the countersunk por-
tion of the intake manifold water box (Figs. 11 and
12). Install new gasket on water box. Install housing
over gasket and thermostat and tighten bolts to 12
N Im (133 in. lbs. torque).
Fig. 9 Thermostat, Housing, and Water BoxÐ2.2/
2.5L Engine
Fig. 10 Thermostat, Housing, and Water BoxÐTurbo III
Ä COOLING SYSTEM 7 - 13

INSTALLATIONÐ3.3L AND 3.8L ENGINE
Place a new gasket (dipped in water) on the water
box surface, center thermostat into opening in the in-
take manifold. Place housing over gasket and ther-
mostat, making sure thermostat is in recess provided
(Fig. 13). Bolt housing to intake manifold, tighten
bolts to 28 N Im (250 in. lbs.). Refill cooling system
(see Refilling System ).
COOLANT
The cooling system is designed around the coolant.
The coolant must accept heat from engine metal, in
the cylinder head area near the exhaust valves. Then
carry this heat to the radiator where the tube/fin as-
semblies of these components can give it up to the
air.
PERFORMANCE
Performance is measurable. For heat transfer pure
water excels (Formul a = 1 btu per minute for each
degree of temperature rise for each pound of water).
This formula is altered when necessary additives to
control boiling, freezing, and corrosion are added as
follows:
² Pure Water (1 btu) boils at 100ÉC (212ÉF) and
freezes at 0ÉC (32ÉF).
² 100 Percent Glycol (.7 btu) can cause a hot engine
and detonation and will raise the freeze point to 22ÉC
(-8ÉF).
² 50/50 Glycol and Water (.82 btu) is the recom-
mended combination that provides a freeze point of
-37ÉC(-35ÉF).The radiator, water pump, engine water
jacket, radiator pressure cap, thermostat, tempera-
ture gauge, sending unit and heater are all designed
for 50/50 glycol. Where required, a 56 percent glycol and 44 percent
water mixture will provide a freeze point of-59ÉC
(-50ÉF).
CAUTION: Richer mixtures cannot be measured
with field equipment which can lead to problems
associated with 100 percent glycol.
SELECTION AND ADDITIVES
The use of aluminum cylinder heads, intake mani-
folds, and water pumps requires special corrosion
protection. Mopar Antifreeze, Prestone II, Peak or
antifreeze containing Alugard 340-2, or their equiva-
lent are recommended for best engine cooling with-
out corrosion. When mixed only to a freeze point of
Fig. 11 Thermostat, Housing, and Water BoxÐ3.0L Engine
Fig. 12 Thermostat InstalledÐ3.0L Engine
Fig. 13 Thermostat, Housing and WaterboxÐ3.3Land 3.8L Engine
7 - 14 COOLING SYSTEM Ä

-37ÉC (-35ÉF) to -59ÉC (-50ÉF). If it looses color or
becomes contaminated, drain, flush, and replace with
fresh properly mixed solution.
SERVICE
Coolant should be changed at 52,500 miles or three
years, whichever occurs first, then every two years or
30,000 miles.
ROUTINE LEVEL CHECK
Do not remove radiator cap for routine coolant
level inspections. The coolant reserve system provides a quick visual
method for determining the coolant level without re-
moving the radiator cap. Simply observe, with the
engine idling and warmed up to normal operating
temperature, that the level of the coolant in the reserve
tank (Figs. 5 and 6) is between the minimum and
maximum marks.
ADDING ADDITIONAL COOLANT
The radiator cap should not be removed. When
additional coolant is needed to maintain this level, it
should be added to the coolant reserve tank. Use only
50/50 concentration of ethylene glycol type antifreeze
and water.
SERVICE COOLANT LEVEL
The cooling system is closed and designed to main-
tain coolant level to the top of the radiator. When servicing requires a coolant level check in the
radiator, the engine must be offand notunder pres-
sure. Drain several ounces of coolant from the radiator
drain cock while observing the Coolant Recovery Sys-
tem (CRS) Tank. Coolant level in the CRS tank should
drop slightly. Then remove the radiator cap. The radia-
tor should be full to the top. If not, and the coolant level
in the CRS tank is at the MIN mark there is a air leak
in the CRS system. Check hose or hose connections to
the CRS tank, radiator filler neck or the pressure cap
seal to the radiator filler neck for leaks.
LOW COOLANT LEVEL AERATION
Low coolant level in a cross flow radiator will equal-
ize in both tanks with engine off. With engine at
running operating temperature the high pressure inlet
tank runs full and the low pressure outlet tank drops.
If this level drops below the top of the transmission oil
cooler, air will be sucked into the water pump:
² Transmission oil will become hotter.
² High reading shown on the temperature gauge.
² Air in the coolant will also cause loss of flow through
the heater.
² Exhaust gas leaks into the coolant can also cause the
same problems.
DEAERATION
Air can only be removed from the system by gather-
ing under the pressure cap. On the next heat up it will
be pushed past the pressure cap into the CRS tank by
thermal expansion of the coolant. It then escapes to the
atmosphere in the CRS tank and is replaced with solid
coolant on cool down.
COOLING SYSTEM DRAIN, CLEAN, FLUSH AND
REFILL
Drain, flush, and fill the cooling system at the
mileage or time intervals specified in the Maintenance
Schedule in this Group. If the solution is dirty or rusty
or contains a considerable amount of sediment, clean
and flush with a reliable cooling system cleaner. Care
should be taken in disposing of the used engine coolant
from your vehicle. Check governmental regulations for
disposal of used engine coolant.
DRAINING
To drain cooling system move temperature selector
for heater to full heat with engine running (to provide
vacuum for actuation). Without removing radiator
pressure cap and with system not under pres-
sure, Shut engine off and open draincock. The coolant
reserve tank (Fig. 5) should empty first, then remove
radiator pressure cap. (if not, see Testing Cooling
System for leaks). To vent 2.2/2.5L engines remove the
plug above thermostat housing (Fig. 1). For Turbo III
engines remove coolant temperature sensor in the
thermostat housing (Fig. 2). For 3.3L /3.8L engine
remove the engine temperature sending unit (Fig. 3).
Removal of a plug or other component is required
because the thermostat has no air vent and prevents
air flow through it. This allows the coolant to drain
from the engine block.
Fig. 1 Thermostat Housing Drain/Fill PlugÐ2.2/2.5L Engines
Ä COOLING SYSTEM 7 - 15