cooling CHEVROLET DYNASTY 1993 User Guide

COOLING SYSTEM DIAGNOSIS
7 - 4 COOLING SYSTEM Ä

COOLING SYSTEM DIAGNOSIS
Ä COOLING SYSTEM 7 - 5

COOLING SYSTEM DIAGNOSIS
7 - 6 COOLING SYSTEM Ä

COOLING SYSTEM DIAGNOSIS
Ä COOLING SYSTEM 7 - 7

COOLING SYSTEM DIAGNOSIS
7 - 8 COOLING SYSTEM Ä

COOLING SYSTEM DIAGNOSIS
Ä COOLING SYSTEM 7 - 9

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

(1) Damage or cracks on the pump body.
(2) Coolant leaks, if the shaft seal is leaking, evi-
dent by traces of coolant leaks from vent hole A in
(Fig. 5). (3) Impeller rubs inside of pump.
(4) Excessively loose or rough turning bearing.
INSTALLATION (1) Clean all gasket and O-ring surfaces on pump
and water pipe inlet tube. (2) Install new O-ring on water inlet pipe (Fig. 6).
Wet the O-ring with water to facilitate assembly.
CAUTION: Keep the O-ring free of oil or grease.
(3) Install new gasket on water pump and install
pump inlet opening over water pipe, press assembly
to cause water pipe insertion into pump housing. (4) Install pump to block mounting bolts and
tighten to 27 N Im (20 ft. lbs.).
(5) See Timing System in Engine, Group 9 and in-
stall timing belt. Reassemble engine. (6) Fill cooling system. See Refilling Cooling Sys-
tem.
WATER PUMPÐ3.3L AND 3.8L ENGINES
The pump has a die cast aluminum body and a
stamped steel impeller. It bolts directly to the chain
case cover, using an O-ring for sealing. It is driven
by the back surface of the Poly-V Drive Belt.
REMOVAL (1) Drain Cooling System. Refer to Draining Cool-
ing System in this group. (2) Remove Poly V Drive Belt.
(3) Remove right front lower fender shield.
(4) Remove pump pulley bolts and remove pulley.
(5) Remove pump mounting screws (Fig. 7). Re-
move pump. (6) Remove and discard O-ring seal. (7) Clean O-ring groove and O-ring surfaces on
pump and chain case cover. Take care not to scratch
or gouge sealing surface.
INSPECTION
Replace the water pump if it has any of the follow-
ing defects. (1) Damage or cracks on the pump body.
(2) Coolant leaks; if the seal is leaking, evident by
traces of coolant leaks from vent hole. (3) Loose or rough turning bearing.
(4) Impeller rubs either the pump body or chain-
case cover.
INSTALLATION
(1) Install new O-ring in O-ring groove (Fig. 8).
(2) Install pump to chain case cover. Torque screws
to 12 N Im (105 in. lbs.).
(3) Rotate pump by hand to check for freedom of
movement. (4) Position pulley on pump. Install screws and
torque to 30 N Im (250 in. lbs.).
Fig. 6 Water Pipe O-Ring
Fig. 7 Water PumpÐ3.3L and 3.8L Engines
Fig. 8 Water Pump Body
7 - 12 COOLING SYSTEM Ä

(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