Rover 214 & 414 Service and Repair Manual - Rover club

9.10 Inlet manifold pre-heater temperature
switch (carburettor engines)
controls the inlet manifold heater circuit (see
illustration).
11 The switch contacts should be closed to
the ON position (ie: continuity should exist)
only at temperatures below 50°C. Remove the
switch and test it as described in paragraphs
2 to 4.
Thermostatically-operated vacuum
switch - carburettor engines equipped
with catalytic converters
12 This switch is screwed into the thermostat
housing.
13 To test the switch, fit two suitable lengths
of hose to the switch and suspend the switch
in a pan of water which is being heated.
Measure the temperature of the water
with a thermometer. Do not let either the
switch or the thermometer touch the pan
itself.
14 Blow down one of the hoses attached to
the switch. The switch should be closed (ie:
passes no air) when the water temperature is
below 70°C. Above 70°C, the switch should
open and air should flow freely through the
hoses. Stop heating the water then allow the
water to cool down and check that the switch
closes at 70°C or just below.
15 If the switch performance is significantly
different from that specified, or if it does not
work at all, then it must be renewed.
Coolant temperature sensor - fuel
injected engines
16 This sensor, which is screwed into the
underside of the inlet manifold (SPi engines),
or located in the coolant pipe adjacent to the
foward top edge of the timing belt cover (MPi
engines), is a thermistor (see paragraph 6)
which is supplied with approximately 5 volts
by the engine management system ECU. The
ECU also controls the sensor’s earth path
and, by measuring the amount of current in
the sensor circuit, determines the engine’s
temperature. This information is used, in
conjunction with other inputs, to control idle
speed, injector opening time duration and
ignition timing.
17 If the sensor circuit should fail to provide
adequate information, the ECU’s back-up
9.20 Remove cooling fan thermostatic
switch and withdraw sealing ring
(arrowed)
facility assumes a value corresponding to
60°C. The sensor itself can be tested only by
having a Rover dealer check the complete
system using the correct diagnostic
equipment. Do not attempt to test the circuit
using any other equipment, or the ECU will be
damaged.
Removal
Cooling fan thermostatic switch
18 With the engine and radiator cold, either
drain the cooling system down to the level of
the sender unit, or unscrew the expansion
tank filler cap to release any remaining
pressure and have a suitable plug ready that
can be used to stop the escape of coolant
while the switch is removed.
19 Disconnect the battery negative lead.
20 Disconnect the wiring connector from the
switch then rotate the locking ring to release
it. Withdraw the switch and sealing ring from
the radiator (see illustration).
Coolant temperature gauge sender
unit
21 With the engine and radiator cold, either
drain the cooling system down to the level of
the switch, or unscrew the expansion tank
filler cap to release any remaining pressure
and have a suitable plug ready that can be
used to stop the escape of coolant while the
unit is removed.
22 Disconnect the battery negative lead.
23 Disconnect the unit’s wiring connector
and unscrew the unit from the coolant outlet
elbow.
Inlet manifold pre-heater temperature
switch - carburettor engines
24 Refer to Chapter 4.
Thermostatically-operated vacuum
switch - carburettor engines equipped
with catalytic converters
25 Refer to Chapter 5.
Coolant temperature sensor - fuel
injected engines
26 Refer to Chapter 4.
1689 Rover 214 & 414 Updated Version 09/97
Cooling, heating and ventilation systems 3•7
9.27 Cooling fan switch locking ring (A)
thermostatic switch (B) and sealing
ring (C)
Refitting
Cooling fan thermostatic switch
27 On refitting, renew the sealing ring if it is
worn or compressed and carefully clean the
radiator seat before pressing in the
sealing ring and switch (see illustration).
Refit the locking ring and rotate it to
tighten it securely. Reconnect the switch
and battery, then replenish the cooling
system.
Coolant temperature gauge sender
unit
28 On refitting, apply a suitable sealant to the
unit threads and tighten it to its specified
torque wrench setting. Reconnect the unit
and battery, then replenish the cooling
system.
Inlet manifold pre-heater temperature
switch - carburettor engines
29 Refer to Chapter 4.
Thermostatically-operated vacuum
switch - carburettor engines equipped
with catalytic converters
30 Refer to Chapter 5.
Coolant temperature sensor - fuel
injected engines
31 Refer to Chapter 4.
10 Heater components -
removal and refitting 3
Removal
Heater unit
1 Drain the cooling system.
2 Working in the engine compartment,
slacken the hose clips and disconnect the
heater feed and return hoses from the matrix
outlets on the bulkhead. Disconnect the cable
inner from the heater valve and free the cable
outer from its retaining clip. Slacken and
3