Chlodzenie Ogrzewanie I Klimatyzacja.pdf

3•1

Chapter 3

Cooling, heating and air conditioning systems

Contents

Air conditioner receiver-drier - removal and refitting . . . . . . . . . . . . 16

Air conditioning blower motor (E28/”old-shape” 5-series

models) - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Air conditioning compressor - removal and refitting . . . . . . . . . . . . . 13

Air conditioning condenser - removal and refitting . . . . . . . . . . . . . . 15

Air conditioning system - precautions and maintenance . . . . . . . . . 12

Antifreeze - general information . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Coolant level check . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1

Coolant temperature sender unit - check and renewal . . . . . . . . . . . 8

Cooling system check . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1

Cooling system servicing (draining, flushing and refilling)See Chapter 1

Engine cooling fan(s) and clutch - check, removal and refitting . . . . 5

Evaporator matrix - removal and refitting . . . . . . . . . . . . . . . . . . . . . 17

General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Heater and air conditioner control assembly - removal and refitting 10

Heater and air conditioning blower motor - removal,testing and

refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Heater matrix - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . 11

Radiator - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Thermostat - check and renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Water pump - check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Water pump - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . 7

Degrees of difficulty

Easy, suitable for

novice with little

experience

Fairly easy, suitable

for beginner with

some experience

Fairly difficult,

suitable for competent

DIY mechanic

Difficult, suitable for

experienced DIY

mechanic

Very difficult,

suitable for expert

DIY or professional

Specifications

General

Coolant capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1

Thermostat rating

Opening temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80°C (176°F)

Fully open at . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100°C (212°F)

Cooling fan thermo-switch - switching temperatures

Low-speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91°C (196°F)

High-speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99°C (210°F)

Torque wrench settings

Mechanical cooling fan clutch-to-water pump securing

nut (left-hand thread) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Mechanical cooling fan-to-clutch bolts . . . . . . . . . . . . . . . . . . . . . . . . . 10

Water pump bolts

Small bolts (M6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Large bolts (M8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Thermostat housing bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

1 General information

around the intake and exhaust ports, near the

spark plug areas, and in close proximity to the

exhaust valve guides.

A wax-pellet-type thermostat is located in-

line in the bottom hose on M10 engines, in a

housing near the front of the engine on M20

and M30 engines, or behind an elbow under

the timing belt upper cover (on the front of the

cylinder head) on M40 engines. During warm-

up, the closed thermostat prevents coolant

from circulating through the radiator. As the

engine nears normal operating temperature,

the thermostat opens and allows hot coolant

to travel through the radiator, where it’s

cooled before returning to the engine.

The pressure in the system raises the

boiling point of the coolant, and increases the

cooling efficiency of the radiator. The cooling

system is sealed by a pressure-type cap. If

the system pressure exceeds the cap

pressure relief value, the excess pressure in

the system forces the spring-loaded valve

inside the cap off its seat, and allows the

coolant to escape through the overflow tube.

The pressure cap on four-cylinder models is

on the top of the radiator; on six-cylinder models,

it’s on top of a translucent plastic expansion

tank. The cap pressure rating is moulded into the

top of the cap. The pressure rating is either

1.0 bar (14 psi) or 1.2 bars (17 psi).

Engine cooling system

All vehicles covered by this manual employ

a pressurised engine cooling system, with

thermostatically-controlled coolant circulation.

An impeller-type water pump mounted on

the front of the block pumps coolant through

the engine. The coolant flows around each

cylinder, and towards the rear of the engine.

Cast-in coolant passages direct coolant

3•2 Cooling, heating and air conditioning systems

Warning: Do not remove the

pressure cap from the radiator or

expansion tank until the engine

has cooled completely and

there’s no pressure remaining in the

cooling system. Removing the cap from a

hot engine risks personal injury by

scalding.

Heating system

The heating system consists of a blower fan

and heater matrix located in the heater box,

with hoses connecting the heater matrix to the

engine cooling system, and the heater/air

conditioning control head on the dashboard.

Hot engine coolant is circulated through the

heater matrix passages all the time the engine

is running. Switching the heater on opens a

flap door to direct air through the heater

matrix, and the warmed air enters the

passenger compartment. A fan switch on the

control head activates the blower motor,

which forces more air through the heater

matrix, giving additional heater output for

demisting, etc.

Air conditioning system

The air conditioning system consists of a

condenser mounted in front of the radiator, an

evaporator mounted adjacent to the heater

matrix, a compressor mounted on the engine,

a filter-drier (receiver-drier) which contains a

high-pressure relief valve, and the plumbing

connecting all of the above components.

A blower fan forces the warmer air of the

passenger compartment through the

evaporator matrix (a radiator-in-reverse),

transferring the heat from the air to the

refrigerant. The liquid refrigerant boils off into

low-pressure vapour, taking the heat with it

when it leaves the evaporator.

Note : Refer to the precautions at the start

of Section 12 concerning the potential

dangers associated with the air conditioning

system.

coolant, and (if of good quality) provides

protection against corrosion.

The cooling system should be drained,

flushed and refilled at the specified intervals

(see Chapter 1). Old or contaminated

antifreeze solutions are likely to cause

damage, and encourage the formation of rust

and scale in the system. Use distilled water

with the antifreeze, if available, or clean

rainwater. Tap water will do, but not if the

water in your area is at all “hard”.

Before adding antifreeze, check all hose

connections, because antifreeze tends to

search out and leak through very minute

openings. Engines don’t normally consume

coolant, so if the level goes down, find the

cause and correct it.

The antifreeze mixture should be

maintained at its correct proportions; adding

too much antifreeze reduces the efficiency of

the cooling system. If necessary, consult the

mixture ratio chart on the antifreeze container

before adding coolant. Hydrometers are

available at most car accessory shops to test

the coolant. Use antifreeze which meets the

vehicle manufacturer’s specifications.

preventing the coolant inside the engine from

circulating to the radiator. Renew the

thermostat.

Caution: Don’t drive the vehicle

without a thermostat. The engine

will be very slow to warm-up in

cold conditions, resulting in poor

fuel economy and driveability. A new

thermostat is normally an inexpensive

component anyway.

4 If the upper radiator hose is hot, it means

that the coolant is flowing and the thermostat

is at least partly open. Consult the “Fault

finding” Section at the rear of this manual for

cooling system diagnosis.

Renewal

All models

5 Disconnect the negative cable from the

battery.

Caution: If the radio in your

vehicle is equipped with an anti-

theft system, make sure you

have the correct activation code

before disconnecting the battery.

Note: If, after connecting the battery, the

wrong language appears on the instrument

panel display, refer to page 0-7 for the

language resetting procedure.

6 Drain the cooling system (see Chapter 1). If

the coolant is relatively new or in good

condition, save it and re-use it.

M10 engines

7 The thermostat is located in the bottom

hose. First remove the cooling fan.

8 Note the fitted position of the thermostat,

then unscrew the hose clamps and withdraw

the thermostat from the hose connections

(see illustration) .

9 Refit the thermostat-to-hose connections,

and tighten the hose clamps.

10 Refit the cooling fan.

M20 and M30 engines

11 Loosen the hose clamp (see illustration) ,

then detach the hose(s) from the thermostat

cover.

3 Thermostat -

check and renewal

Check

1 Before assuming the thermostat is to blame

for a cooling system problem, check the

coolant level, drivebelt tension (see Chapter 1)

and temperature gauge (or warning light)

operation.

2 If the engine seems to be taking a long time

to warm up (based on heater output or

temperature gauge operation), the thermostat

is probably stuck open. Renew the

thermostat.

3 If the engine runs hot, use your hand to

check the temperature of the upper radiator

hose. If the hose isn’t hot, but the engine is,

the thermostat is probably stuck closed,

2 Antifreeze -

general information

Warning: Do not allow antifreeze

to come in contact with your skin

or painted surfaces of the

vehicle. Rinse off spills

immediately with plenty of water. If

consumed, antifreeze can be fatal;

children and pets are attracted by its

sweet taste, so wipe up garage floor and

drip pan coolant spills immediately. Keep

antifreeze containers covered, and repair

leaks in your cooling system as soon as

they are noticed.

The cooling system should be filled with a

60/40% water/ethylene-glycol-based anti-

freeze solution, which will prevent freezing

down to approximately -27°C (-17°F). The

antifreeze also raises the boiling point of the

3.8 On the M10 (four-cylinder) engine, the

thermostat (arrowed) is connected in-line

in the radiator hose

3.11 On M20 and M30 engine models,

loosen the hose clamp (A) and disconnect

the hose from the thermostat housing

cover - note that the coolant temperature

sender unit (barely visible behind the fuel

pressure regulator) is located at the top of

the thermostat housing (B)

Warning: Do not remove the

radiator cap, drain the coolant, or

renew the thermostat until the

engine has cooled completely.

Cooling, heating and air conditioning systems 3•3

3.15 On M20 and M30 engine models,

after the housing and thermostat have

been removed, take the O-ring out of the

housing and clean the recess in the

housing to be sure of a good seal upon

reassembly

3.20a Removing the elbow from the

cylinder head (M40 engine)

3.20b Removing the thermostat

(M40 engine)

bottom hose from the elbow on the front of

the cylinder head.

20 Unbolt the elbow from the cylinder head.

Note the fitted position of the thermostat, then

remove it (see illustrations) . Remove the

rubber O-ring; a new one will be needed for

reassembly.

21 Locate the thermostat in the cylinder head

in the same position as noted during removal

(arrow pointing upwards).

22 Press a new O-ring in the groove, and

locate the elbow on the cylinder head. Tighten

the bolts.

23 Connect the bottom hose to the elbow,

and tighten the hose clamp.

24 Refit the upper timing belt cover and

cooling fan.

All models

25 Refill the cooling system (see Chapter 1).

26 Connect the battery negative cable.

27 Start the engine and allow it to reach

normal operating temperature, then check for

leaks and proper thermostat operation (as

described earlier in this Section).

Note : I f the radiator is being removed because

it is leaking, note that minor leaks can often be

repaired without removing the radiator, using

a radiator sealant.

Caution: If the radio in your

vehicle is equipped with an anti-

theft system, make sure you

have the correct activation code

before disconnecting the battery.

Note: If, after connecting the battery, the

wrong language appears on the instrument

panel display, refer to page 0-7 for the

language resetting procedure.

Removal

1 Disconnect the battery negative cable.

2 Drain the cooling system (see Chapter 1). If

the coolant is relatively new, or in good

condition, save it and re-use it.

3 Loosen the hose clamps, then detach the

hoses from the radiator (see illustrations) . If

they’re stuck, grasp each hose near the end

with a pair of water pump pliers, twist gently

to break the seal, then pull off - be careful not

to distort or break the radiator outlets! If the

hoses are old or deteriorated, cut them off

and refit new ones.

4 On M20 and M30 engines, disconnect the

reservoir hose from the radiator filler neck.

5 Remove the screws or plastic fasteners that

attach the shroud to the radiator, and slide the

shroud towards the engine (see illustration) .

On some engines it is possible to completely

remove the shroud.

6 If the vehicle has automatic transmission,

12 If the outer surface of the fitting that

mates with the hose is deteriorated (corroded,

pitted, etc.), it may be damaged further by

hose removal. If it is, a new thermostat

housing cover will be required.

13 Remove the bolts and detach the housing

cover. If the cover is stuck, tap it with a soft-

faced hammer to jar it loose. Be prepared for

some coolant to spill as the gasket seal is

broken.

14 Note how it’s fitted, then remove the

thermostat.

15 Stuff a rag into the engine opening, then

remove all traces of old gasket material (if the

gasket is paper type). Otherwise, remove the

rubber O-ring (see illustration) and sealant

from the housing and cover with a gasket

scraper. Remove the rag from the opening

and clean the gasket mating surfaces.

16 Fit the new thermostat and gasket in the

housing. Make sure the correct end faces out

- the spring end is normally directed towards

the engine.

17 Refit the cover and bolts. Tighten the

bolts to the torque listed in this Chapter’s

Specifications.

M40 engines

18 Remove the cooling fan and timing belt

upper cover.

19 Unscrew the hose clamp and detach the

4 Radiator -

removal and refitting

Warning: Wait until the engine is

completely cool before beginning

this procedure.

4.3a Disconnecting the top hose from the

radiator

4.3b Bottom hose connection to the

radiator

4.5 Plastic fastener retaining the radiator

shroud on some engines

3•4 Cooling, heating and air conditioning systems

4.7 Sensors that control the high- and

low-speed operation of the auxiliary

cooling fan are located in various places in

the radiator tanks

4.8 The radiator is bolted to the front

panel at either the sides or the top of the

radiator

good chance the switch is malfunctioning. To

more accurately diagnose the problem, follow

the steps that apply to your model. Note : Spin

the auxiliary fan motor by hand, to check that

the motor or fan isn’t binding. Make sure,

however, that the engine is sufficiently cool

that there is no danger of the fan cutting-in on

its own when this is done .

4 To test the low-speed and high-speed

circuits, disconnect the electrical connector

from one of the fan switches, and bridge the

terminals of the switch’s electrical connector

with a short piece of wire. The fan should run

at low or high speed, depending on which

switch has been disconnected. On some

models the ignition must be on before the fan

will run.

5 Repeat the test at the other switch so that

both high and low speeds are tested.

6 If the low-speed and high-speed circuits

are OK, but there has been a problem with the

fan not operating correctly in service, renew

the switch (or switches). To remove a switch,

drain the coolant below the level of the switch

(see Chapter 1), then unscrew the switch and

screw in the new one. Refill the system with

coolant.

7 If the switches are satisfactory, but the

motor still does not operate, the problem lies

in the fuse, the relay, the wiring which

connects the components (or the fan motor

itself). Carefully check the fuse, relay, all

wiring and connections. See Chapter 12 for

more information on how to carry out these

checks.

Mechanical fan with viscous clutch

8 Disconnect the battery negative cable, and

rock the fan back and forth by hand to check

for excessive bearing play.

Caution: If the radio in your

vehicle is equipped with an anti-

theft system, make sure you

have the correct activation code

before disconnecting the battery.

Note: If, after connecting the battery, the

wrong language appears on the instrument

panel display, refer to page 0-7 for the

language resetting procedure.

9 With the engine cold, turn the fan blades by

hand. The fan should turn with slight

resistance.

10 Visually inspect for substantial fluid

leakage from the fan clutch assembly. If

problems are noted, renew the fan clutch

assembly.

11 With the engine completely warmed up,

turn off the ignition switch and disconnect the

battery negative cable. Turn the fan by hand.

Heavier resistance should be evident. If the

fan turns easily, a new fan clutch may be

needed.

Removal and refitting

Electric auxiliary fan

12 Disconnect the battery negative cable.

13 To remove the auxiliary fan follow the

procedure that applies to your vehicle.

disconnect the fluid cooler lines from the

radiator. Use a drip tray to catch spilled fluid.

Plug the fluid cooler lines and fittings.

7 Disconnect the coolant sensors located on

the radiator (see illustration) . The thermo-

statically-controlled switches for high- and

low-speed operation of the auxiliary fan are

located in the radiator tanks, in various

locations depending on engine and model.

8 Remove the radiator mounting bolt(s). The

mountings are either on the top or sides of the

radiator (see illustration) .

9 Carefully lift out the radiator from the

bottom mountings, taking care not to damage

the cooling fins. Don’t spill coolant on the

vehicle, or scratch the paint.

10 With the radiator removed, it can be

inspected for leaks and damage. If it needs

repair, have a specialist perform the work, as

special techniques are required.

11 Flies and dirt can be removed from the

radiator with compressed air and a soft brush.

Don’t bend the cooling fins as this is done.

12 Check the radiator mountings for

deterioration, and renew if necessary (see

illustration).

Refitting

13 Refitting is the reverse of the removal

procedure.

14 After refitting, fill the cooling system with

the proper mixture of antifreeze and water.

Refer to Chapter 1 if necessary.

15 Start the engine and check for leaks.

Allow the engine to reach normal operating

temperature, indicated by the upper radiator

hose becoming hot. Recheck the coolant

level, and add more if required.

16 If you’re working on an automatic

transmission model, check and add

transmission fluid as needed.

5 Engine cooling fan(s) and

clutch - check, removal and

refitting

Warning: To avoid possible injury

or damage, DO NOT operate the

engine with a damaged fan. Do

not attempt to repair fan blades -

fit a new fan. Also, the electric auxiliary fan

in front of the radiator or air conditioning

condenser can come on without the

engine running or ignition being on. It is

controlled by the coolant temperature of

the thermo-switches located in the

radiator.

Check

Electric auxiliary fan

Note : This fan on most models is controlled

by two thermo-switches placed in the radiator:

one for low-speed/low-temperature operation,

and one for high-speed/high-temperature

operation. Each switch comes on at a different

coolant temperature (refer to the Specifica-

tions at the beginning of this Chapter) .

1 The thermostatically-controlled switches for

high- and low-speed operation of the auxiliary

fan are fitted in various locations in the

radiator (see illustration 4.7) , depending on

engine or model. Two single switches, or one

dual switch, may be fitted.

2 Insert a small screwdriver into the

connector to lift the lock tab, and unplug the

fan wire harness.

3 To test the fan motor, unplug the electrical

connector at the motor, and use jumper wires

to connect the fan directly to the battery. If the

fan doesn’t work when connected directly to

the battery, the motor is proved faulty, and

must be renewed. If the fan works, there’s a

4.12 When the radiator is out, the radiator

mountings can be inspected - check for

signs of deterioration, and renew them, if

needed

Cooling, heating and air conditioning systems 3•5

5.27a The cooling fan on the water pump

is attached to the shaft by a left-hand-

threaded nut located directly behind the

fan . . .

5.27b . . . to loosen the nut, place a 32 mm

open-ended spanner on the nut, and

sharply strike the spanner (A) with a metal

drift (B) and hammer; this will loosen the

nut and allow it to be turned easily so the

fan can be removed

5.29 Removing the water pump pulley

(M40 engine)

Caution: If the radio in your

vehicle is equipped with an anti-

theft system, make sure you

have the correct activation code

before disconnecting the battery.

Note: If, after connecting the battery, the

wrong language appears on the instrument

panel display, refer to page 0-7 for the

language resetting procedure.

Removal

1 Disconnect the battery negative cable.

2 Drain the cooling system (see Chapter 1). If

the coolant is relatively new, or in good

condition, save it and re-use it.

3 Remove the cooling fan shroud (see

Section 5).

4 Remove the drivebelts (see Chapter 1).

5 Where applicable, loosen the clamps and

detach the hoses from the water pump. If

they’re stuck, grasp each hose near the end

with a pair of water pump pliers and gently

twist it to break the seal, then pull it off. If the

hoses are deteriorated, cut them off and refit

new ones.

6 Remove the fan and clutch assembly and

the pulley at the end of the water pump shaft

(see Section 5).

7 To remove the water pump, follow the

specific steps that apply to your engine.

M10 engine

8 Unscrew the mounting bolts and remove

the water pump (see illustration) .

3-Series models

14 Remove the radiator grille assembly (see

Chapter 11).

15 Unbolt and remove the fan bracket and

shroud assembly from the radiator (see

Section 5).

16 Remove the radiator (see Section 4).

17 Unbolt the air conditioning condenser

mounting bolts, where applicable. Do not

remove the condenser or disconnect any

refrigerant lines from the condenser.

18 Carefully pull the condenser back towards

the engine, slightly, to gain access to lift the

auxiliary fan.

19 Disconnect the fan motor electrical

connection and remove the auxiliary fan.

20 Refitting is the reverse of removal.

30 Carefully inspect the fan blades for

damage and defects. Renew it if necessary.

31 At this point, the fan may be unbolted

from the clutch, if necessary. If the fan clutch

is stored, position it with the radiator side

facing down.

32 Refitting is the reverse of removal.

6 Water pump - check

1 A failure in the water pump can cause

serious engine damage due to overheating.

2 There are two ways to check the operation

of the water pump while it’s fitted on the

engine. If either of the following checks

suggest that the pump is defective, a new one

should be fitted.

3 Water pumps are equipped with “weep” or

“vent” holes. If a failure occurs in the pump

seal, coolant will leak from the hole. In most

cases, you’ll need a torch to find the hole on

the water pump from underneath to check for

leaks.

4 If the water pump shaft bearings fail, there

may be a howling sound at the front of the

engine while it’s running. Shaft wear can be

felt if the water pump pulley is rocked up and

down (with the drivebelt removed). Don’t

mistake drivebelt slippage, which causes a

squealing sound, for water pump bearing

failure. Alternator bearing failure can also

cause a howling sound, but after removing the

drivebelt(s) it should be easy enough to tell

which component is responsible.

5-Series models

21 Remove the screws and trim panel in front

of the radiator.

22 Unbolt the fan assembly from the

condenser mounting points.

23 Disconnect the fan electrical connector.

24 Remove the fan and housing from the car,

being careful not to damage the air

conditioning condenser (when applicable)

while removing the fan.

25 Refitting is the reverse of removal.

Mechanical fan with viscous clutch

26 Disconnect the battery negative cable.

Remove the fan shroud mounting screws or

plastic fasteners, and detach the shroud (see

Section 4).

27 Use a 32 mm open-ended spanner to

remove the fan/clutch assembly. Place the

spanner on the large nut ahead of the pulley

(see illustrations) , and tap the end of the

spanner to loosen the nut.

Caution: The nut has left-handed

threads, so it loosens by being

turned clockwise, as viewed from

the front of the vehicle.

28 Lift the fan/clutch assembly (and shroud,

if necessary) out of the engine compartment.

29 If necessary, remove the four bolts

attaching the pulley to the water pump hub.

The pulley can then be removed after

removing the drivebelt(s) (see illustration) .

7 Water pump -

removal and refitting

Warning: Wait until the engine is

completely cool before beginning

this procedure.

7.8 On M10 engines, there are seven bolts

(locations arrowed) that hold the water

pump to the block

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