2-5 ENGINE COOLING SYSTEM SUBARV SVX 1992 M Page MECHANISM AND FUNCTION General 2 Cooling Lines Water Pump Mechanical Seal Thermostat S SPECIFICATIONS AND SERVICE DATA A: SPECIFICATIONS B: SERVICE DATA C COMPONENT PARTS Water Pump Radiator and Radiator Fan Water Pipe W SERVICE PROCEDURE Water Pump Thermostat Radiator Radiator Cap Radiator Fan and Fan Motor 5 6 9 11 11 13 14 T TROUBLESHOOTING 15 t+++ 2-5 [M100) ENGINE COOLING SYSTEM M MECHANISM AND FUNCTION ECU sends ON or OFF, and Lo (low) MID (medium) or Hi (high) switch signals to the radiator main fan and sub fan in response to signals from the water temperature sensor, vehicle speed sensor 2, A/C switch and A/C trinary switch General The engine cooling system consists of a down-flow radiator which features high heat-dissipation performance, an electric motor fan, a water pump, a thermostat, and a thermometer The reserve tank is designed to eliminate the need for replenishing coolant i Water temperature sensor I 3I Radiator main fan -, Vehicle speed sensor ECU A/C switch I -I I- - Radiator sub fan A/C trinary switch Cool ing Lines 2) 2nd step With thermostat opened When the coolant temperature is above 76 - 80°C (169 - 176°F), the thermostat opens and the coolant flows through the radiator where it is cooled 3) 3rd step With electric cooling fan operating When the coolant temperature rises above 95°C (203°F), the water temperature sensor is turned on and radiator fan rotates This cooling system operates in three steps depending on the temperature of the coolant flowing through the cooling circuit 1) 1st step With thermostat closed At coolant temperature of below 76°C (169°F), the thermostat remains closed and the coolant flows through the bypass and heater circuits This permits the engine to warm up quickly Cylinder hea r I nlet Throttle body Cylinder block RH Cylinder jacket R H Water Pum p Radiator -di Cylinder jacket LH Outlet - Thermostat I Cylinder block LH + _ Cylinder head LH Heater Reservoir tank C2-001 Fig ENGINE COOLING SYSTEM Water Pump [Maoo) 2-5 rotates, engine coolant is drawn into the water pump from the lower pipe (which is connected to the radiator hose) via the thermostat It then flows along the perimeter of the impeller and is delivered to the engine's water passage The water pump is located on the left front portion of the cylinder block and is driven by the back of the timing belt The thermostat is built into the water inlet located on the lower side of the water pump When the impeller Mechanical seal Pulley O Pulley 0 CC I Jingle valve n ® ~m i" Thermostat cover I~ impeller L- Thermostat L Thermostat cover C2-002 Fig Mechanical Seal Carbon seal Ceramics seat The mechanical seal has its seat pressed into the water pump shaft to form the seal and water pump as a single unit With this design, the water pump cannot be disassembled z Water pump shaft Fig 3 B2-221 2-5 [M500) ENGINE COOLING SYSTEM Thermostat creased temperature It provides the sure open-close operation of the valve and features high durability The thermostat is powered to open the valve by a totally-enclosed wax pellet which expands with in- ® O O r jingle valve u U © Valve Spring Stopper Piston Guide Gum packing Stop ring Wax element i ~~(\ 2 O O 82-222 Fig 4 2-5 [SOA01 S ENGINE COOLING SYSTEM SPECIFICATIONS AND SERVICE DATA A: SPECIFICATIONS Electric fan + Forced engine coolant circulation system Cooling system Total coolant capacity 7.5 C (7 US qt, 6.6 Imp qt) Type Centrifugal impeller type Discharge Discharge performance I Pump speed -total water head Engine coolant tempera- ture Discharge Discharge performance II Engine coolant pump Pump speed -total water head Engine coolant tempera- ture Discharge Discharge performance III Pump speed -total water head Engine coolant tempera- ture Impeller diameter Number of impeller vanes 3,000 rpm - 5.0 mAq (16.4 ft Aq) 85-C (185°F) 200 C (52.8 US gal, 44.0 Imp gal)/min 6,000 rpm -23.0 mAq (75.5 ft Aq) 85°C (185°F) 76 mm (2 99 in) Wax pellet type Fully opens Motor Fan dia x blade Motor Fan dia x blade Type Core dimensions Radiator Pressure range in which cap valve is open Fins Reservoir tank 100 C (26.4 US gal, 22.0 Imp gal)/min Type Valve bore Fan control (sub) 85°C (185°F) 60 mm (2 36 in) Valve lift Fan control (main) 760 rpm - 0.3 mAq (1 ft Aq) Pump pulley diameter Starts to open Thermostat 20 Q (5 US gal, 4.4 Imp gal)/min Capacity 76 -80°C (169 - 176°F) 91°C (196°F) 9.0 mm (0 354 in) or more 35 mm (1 38 in) 175 W 320 mm (12 60 in) x 175 W 320 mm (12 60 in) x Down-flow, pressure type 691 x 345 x 25 mm (27.20 x 13.58 x 0.98 in) Above 88 f 10 kPa (0 t0.1 kg/cm2, 13 f 1.4 psi) Below -4 to -10 kPa (-0.05 to -0.1 kg/cm2, -0 to -1 psi) Corrugated fin type 0.55 E (0 US qt, 0.5 Imp qt) 2-5 [C100] ENGINE COOLING SYSTEM C COMPONENT PARTS Water Pump °~ C r Al-~L~-~-~ -r J T2 Gasket Water pump CP Heater hose (Inlet) Heater hose (Outlet) Thermostat Gasket Tightening torque : N.m (kg-m, ft-Ib) T1 : First 10-14(1 0-1 4,7-10) Second 10 -14 (1 -1 4,7 -10) T2 : 6-7 (0 6-0 7,4 3-5 1) Thermostat cover C2-003 Fig [C2oo] 2-5 ENGINE COOLING SYSTEM COMPONENT PARTS C Radiator and Fan Control T2 T1 © ~ _ T2 / T2 Tz 10 I I 70 i- C V ~ T3 11 `i i I ®- -C 'P`' - - -I S~`Er I I i I I I I I I~ I I ~~p A I I E2] II `I~ ~ I I O I I I I I I I I I I I I 19 I 14 10 11 12 13 14 15 ~/mot\-I I /~ 18 16 17 18 19 Tightening torque : N-m (kg-nn, ft-Ib) T1 :13-23(1 3-2 3,9-17) T2 :5 5-9.5(0.56-0.97,4.06-7.01) T3 : 4.5 - 7.5 (0 46 - 0.77, 3.32 - 5.53) 20 21 22 Radiator Upper cushion Upper bracket Radiator inlet hose Clamp Fan control (main) shroud (Fan control (main) and motor Fan control (sub) shroud Fan control (sub) and motor Reservoir tank cover Reservoir tank Over flow hose Radiator outlet hose Clamp ATF cooler inlet hose A ATF cooler outlet hose A ATF cooler pipe ATF cooler inlet hose B ATF cooler outlet hose B Lower cushion Engine coolant drain cock Drain pipe C2-518 Fig 2-5 [C3001 ENGINE COOLING SYSTEM Water Pipe Water pipe CP Water temperature gauge Water temperature sensor O-ring O-ring Auxiliary air control valve // I I I ~y~~tc~n~~y t-yuo T A l -n1 \ny-n~, ~t-lul R_71Y1R-f17 AZ_F 11 C2-005 Fig ENGINE COOLING SYSTEM W SERVICE PROCEDURE Water Pump [W1A0] 2-5 12) Remove left side camshaft pulley A: REMOVAL 1) 2) 3) 4) Open the front hood Disconnect the ground cable from the battery Drain the coolant completely Disconnect the radiator outlet hose 5) Disconnect radiator fan motor connector r © OA ' ~ `tt ~/ " ll0tfe ~ / U r 1" u 13) Remove left side rear timing belt cover - s -r Radiator main fan motor connector Radiator sub fan motor connector C1-042 Fig 6) Remove radiator bracket 7) Remove radiator sub fan motor ASSY Rear timing belt cover L.H Radiator Radiator sub-fan ator main fan C2-007 Fig 11 14) Remove tensioner bracket I Fig 15) Disconnect radiator hose and heater hose from water pump 16) Remove water pump 1- v -'\~,\ -v Water pump ASSY o C2-015 8) Remove V-belt(s) (Refer to "Chapter 1-5 section 1" ) 9) Remove timing belt (Refer to "Chapter 1-5 section 2" ) 10) Remove tensioner adjuster 11) Remove cam angle sensor Fig 12 C2-008 2-5 [w1 Bo) ENGINE COOLING SYSTEM B: INSPECTION 1) Check water pump bearing for smooth rotation 2) Check water pump pulley for abnormalities 3) Using a dial gauge, measure impeller runout in thrust direction while rotating the pulley "Thrust" runout limit : 0.5 mm (0 020 in) 5) After water pump installation, check pulley shaft for water leaks If leaks are noted, replace water pump AS SY FC- INSTALLATION Installation is in the reverse order of removal a Always use a new gasket b When installing water pump, tighten all bolts in two steps in numerical sequence as shown in Figure Pulley O `-~ b C2-009 Fig 13 l-' ° C2-006 Fig 15 Tightening torque : N "m (kg-m, ft-Ib) First: 10-14(l.0-1 4,7-10) Second : 10-14(1 0-1 4,7-10) Clearance between impeller and pump case: Standard 0.5 - 0.7 mm (0 020 - 0.028 in) Limit mm (0 039 in) c After reinstalling the water pump, run the engine to make sure that neither water leakage nor abnormal noise exists Fig 14 + ' Thermostat cover 4) Check clearance between impeller and pump case O C2-010 10 ENGINE COOLING SYSTEM Thermostat [W3B0] 2-5 Radiator ~A: REMOVAL AND INSTALLATION A: ON CAR SERVICE 1) Remove the thermostat case cover and gasket, and pull out the thermostat 2) Install the thermostat in the intake manifold, and install the thermostat cover together with a gasket 1) Remove radiator cap, top off radiator, and attach tester to radiator in place of cap 2) Apply a pressure of 157 kPa (1 kg/cMZ, 23 psi) to radiator to check if: (1) Water leaks at/around radiator a When reinstalling the thermostat, use a new gasket b The thermostat must be installed with the jiggle pin upward c In this time, set the jiggle pin of thermostat for front side (2) Water leaks at/around hoses or connections B : INSPECTION Replace the thermostat if the valve does not close completely at an ambient temperature or if the following test shows unsatisfactory results Immerse the thermostat and a thermometer in water Raise water temperature gradually, and measure the temperature and valve lift when the valve begins to open and when the valve is fully opened During the test, agitate the water for even temperature distribution The measurement should be to the specification Fig 17 a Engine should be off b Wipe water from check points in advance c Be careful to prevent cooling water from spurting out when removing tester Starts to open: 76.0 - 80 0°C (169 - 176°F) Fully opens: 91°C (196°F) d Be careful also not to deform filler neck of radiator when installing or removing tester B : REMOVAL 1) Disconnect battery cables and remove battery from body 2) Lift up the vehicle, and remove lower cover 3) Drain coolant from radiator (1) Fit end of vinyl tube into drain pipe (2) Loosen drain cock and drain coolant Refer to C.1-5 Thermometer Thermostat Fig 16 B2-230 Fig 18 11 2-5 [w3B0] ENGINE COOLING SYSTEM 4) Disconnect outlet hose from water pump Drain coolant into container 5) Disconnect ATF cooler hose from pipe a Drain ATF into container 1f11 flicrnnnPrt inlat hn,,P from watar ninp_ h_ Clan the nine holes so as not to snill ATF_ y - 111 RPmnvp rarfiatnr unner hracket - 6) Lower the vehicle 71 nisr_nnne(-t radiator fan motor ronnectors_ 12) Lift radiator up and away from vehicle 8) Remove over-flow hose from radiator 9) Remove V-belt cover \ _ Fig 23 12 11 ~ C2-014 ENGINE COOLING SYSTEM C: [W4A0) 2-5 Radiator Cap INSTALLATION 1) Fit cushions on body and install radiator A: INSPECTION 1) Attach radiator cap to tester 2) Increase pressure until tester gauge pointer stops Radiator cap is functioning properly if it holds the service limit pressure for five to six seconds Fig 24 C2-016 2) Install radiator brackets and tighten bolts 3) Connect radiator main fan and sub fan motor connectors 4) Connect inlet hose and over-flow hose 5) Install V-belt cover 6) Lift up the vehicle, and connect outlet hose and ATF cooler hose 7) Install lower cover 8) Install battery and connect cables 9) Pour coolant Fig 25 Bl-065 Standard pressure : 78 - 98 kPa (0.8 - 1.0 kg/cm2, 11 - 14 psi) Service limit pressure : 69 We (0.7 kg/cm', 10 psi) (1) Pour coolant into radiator up to filler neck position Be sure to remove foreign matter and rust from the cap in advance; otherwise, results of pressure test will be incorrect (2) Pour coolant into reservoir tank up to upper level (3) Attach radiator cap and reservoir tank cap properly (4) Warm up engine completely (For more than minutes at 2,000 to 3,000 rpm.) (5) Stop engine and wait until temperature drops to a safe level (6) Remove radiator cap (7) If coolant level drops in radiator, add coolant to filler neck position (8) If coolant level drops from upper level of reservoir tank, add coolant to upper level (9) Attach radiator cap and reservoir tank cap properly 10) Check ATF level 13 ENGIN E COOLING SYSTEM 2-5 [w500] Radiator Fan and Fan Motor A: REMOVAL 1) Disconnect ground cable from battery terminal 2) Disconnect connector from fan motor 3) Remove radiator bracket 4) Remove two bolts holding shroud to radiator upper side 5) Remove radiator fan ASSY Radiator sub-fan r- Radiator main fan Fig 26 C2-015 6) Remove fan motor from shroud B: INSTALLATION Installation is in the reverse order of removal procedures Observe the following : 1) Before installing radiator fan motor, apply a coat of sealant to threads and tighten nuts Tightening torque : Nam (kg-m, ft-11b) 2-3 (0.2-0.3, 4-2.2) 2) Make sure radiator fan does not come into contact with shroud when installed 3) After installation, make sure there is no unusual noise or vibration when fan is rotated 14 ENGINE COOLING SYSTEM T TROUBLESHOOTING Trouble Over-heating Possible cause Coolant leaks Noise Corrective action a Insufficient coolant Replenish coolant, inspect for leakage, and repair b Loose drive belt Adjust drive belt tension c Oil on drive belt Replace d Malfunction of thermostat Replace e Malfunction of water pump Replace f Clogged coolant passage Clean g Improper ignition timing Adjust h Clogged or leaking radiator Clean or repair, or replace i Improper engine oil Replace j Air-fuel mixture too thin Excessive back pressure in exhaust system k I O ver-cooli ng [TOOol 2-5 Insufficient clearance between piston and cylinder Inspect and repair fuel system Clean or replace Adjust or replace m Slipping clutch Repair or replace n Dragging brake Adjust o Improper transmission oil Replace p Defective thermostat Replace q Malfunction of radiator fan Inspect radiator fan relay, water temperature sensor or motor, and replace there a Atmospheric temperature extremely low Party cover radiator front area b a Defective thermostat Loosened or damaged connecting units on hoses Replace Repair or replace b Leakage from water pump Replace c d Leakage from intake manifold Leakage around cylinder head gasket e Damaged or cracked cylinder head and crankcase Repair or replace Retighten cylinder head nuts or replace gasket Repair or replace f g Damaged or cracked thermostat case Leakage from radiator Repair or replace Repair or replace a Defective drive belt Replace b Defective electric fan Replace c Defective water pump bearing d Defective water pump mechanical seal Replace water pump I Replace water pump 15 ... torque : N.m (kg-m, ft-Ib) T1 : First 10- 14(1 0-1 4,7 -10) Second 10 -14 (1 -1 4,7 -10) T2 : 6-7 (0 6-0 7,4 3-5 1) Thermostat cover C2-003 Fig [C2oo] 2-5 ENGINE COOLING SYSTEM COMPONENT PARTS C Radiator... in) Above 88 f 10 kPa (0 t0.1 kg/cm2, 13 f 1.4 psi) Below -4 to -10 kPa (-0.05 to -0.1 kg/cm2, -0 to -1 psi) Corrugated fin type 0.55 E (0 US qt, 0.5 Imp qt) 2-5 [C100] ENGINE COOLING SYSTEM... pump, run the engine to make sure that neither water leakage nor abnormal noise exists Fig 14 + '' Thermostat cover 4) Check clearance between impeller and pump case O C2- 010 10 ENGINE COOLING SYSTEM