SECTION 05: COOLING SYSTEM
DOB 2490-2789 | X3-45 Commuter PA1605 Maintenance Manual (Final Version – Rev.2 April 2016)
7
NOTE
Check to be sure that the thermostat closes
fully. This can be done by holding it up to the
light to check that there is no visible gap at the
opening point. If the thermostat does not close
properly, replace it.
1. Warm up water in a receptacle to 75°C
(167°F) and immerse the thermostat in the
water. Use a piece of wire attached to the
thermostat.
2. After at least 30 seconds, check that the
thermostat is still closed.
3. Now warm the water to 100°C (212°F). After
at least 30 seconds at the boiling point,
check that the thermostat has opened at
least 7mm (9/32”). If the thermostat has not
opened, it must be replaced. A good
thermostat starts to close at 95°C (203°F)
and is fully closed at approximately 85°C
(185°F).
5. COOLANT
5.1 COOLANT LEVEL VERIFICATION
Check the coolant level when the engine is cold
(room or ambient temperature).
If the coolant level has reached the bottom of the
sight glass, add coolant up to the middle of the
sight glass.
Fill the tank as required with the same 50/50
water-antifreeze mixture already in the cooling
system.
Do not
mix two different types of
coolant. Refer to the Maintenance Manual for
proper coolant type specifications or see the
label affixed near the coolant surge tank on the
vehicle.
When the coolant level reaches the low coolant
sensor, the red warning light located next to the
tank in the engine compartment will illuminate to
indicate the need to add coolant to the system.
If the coolant level reaches the coolant surge
tank critically low level sensor, the STOP telltale
light illuminates, a beeping tone is heard and
“
ENGINE COOLANT LEVEL CRITICALLY LOW
”
message appears in the DID. Stop the vehicle in
a safe location and add coolant to the cooling
system surge tank as soon as possible.
FIGURE 13: COOLANT LEVEL SIGHT GLASS
05094_3
WARNING
Hot engine coolant is under high pressure.
Allow engine to cool down before adding
coolant.
5.2 COOLANT LEVEL SENSORS
This warning device consists of two fluid level
probes mounted on the surge tank. The first
probe (upper) is a low coolant level warning and
will send a signal to the indicator light located
near the tank in the engine compartment (Figure
1).
The second probe (lower) is a critically low
coolant level warning and will send a signal to
the engine control module to indicate coolant
level. If the coolant level drops below the probe,
the
"Check Engine"
light flashes and a
diagnostic code is registered (see section 01
"
ENGINE"
).
CAUTION
Do not run engine with the “Check Engine”
light flashing.
Both level probes are mounted on the front of
the surge tank (Figure 13).
