The water temperature of BMW 523li is too high.

1. Water thermometer: used to indicate the temperature of cooling water inside the engine, which is an important indicator of whether the engine cooling system works normally.

2. What do you think of the water thermometer?

The water temperature from C-H, C means 60 degrees. As long as the pointer of the water thermometer reaches C, the water temperature has reached 60 degrees. H The temperature indicated by the red grid is 1 10 degrees. It is recommended to always keep the pointer in the middle position. When the pointer enters the red area with super anchor, the water temperature will be too high. If the water temperature is too high for a long time, "boiling" will occur, that is, the engine coolant will boil, which will cause the water tank to burst and the engine to overheat and be damaged.

3. Working principle

The negative temperature coefficient is installed in the sensor.

electric resistance

value

can

Have temperature

rise

high

And reduce.

When the power switch is turned on, the current flows from the positive electrode of the battery to→

Power switch →

Resistance r→

roll

l2

→

Divided into two paths (one path flows through the thermistor

1; Another kind of flow

Warp loop

l 1

)→

Grounding →

The negative electrode of the battery forms a loop.

When the water temperature is low, the thermistor in the sensor has a large resistance and flows through the coil.

l 1

and

L2 current is similar, but due to

l 1

about

number of windings

productive

raw

magnetic field

Strong belt

needle

Armature of

three

Will deflect to the left, so that the pointer points to the low temperature scale; When the water temperature rises, the resistance of thermistor decreases and the shunt effect increases.

l 1

Current decreases, magnetic field force

Weakening, armature deflection to the right, pointer pointing to high temperature scale.

4. Check the thermometer

When checking the electromagnetic temperature sensor and water temperature indicator, you can remove the wiring on the sensor and measure the resistance between the input end of the sensor and the ground.

Ruoshi

Temperature sensitivity

Resistance resistance

The value is

100

ω

Left and right, indicating that the sensor is good; Use another one.

Resistance is

80

~ 100

ω

Resistors directly replace sensors.

Grounding during connection

Charge

Source time, for example

fruit

water temperature

show

flat

watch hand

point to

exist

60℃

~

70℃

, indicating that the water temperature indicator is good.