Examination
Disconnect connector.
Connect an ohmmeter to both pins of the connector.
Measure the resistance and compare with the specified value. Intermediate values are possible at different temperatures. See the table below for set values.
If the result differs from the specified value, remove the sensor.
Place the sensor on the wire hook in the water bath so that it does not touch the walls of the vessel. Cool the water with pieces of ice, and then heat it up on the stove. At given temperatures, remove the sensor and measure the resistance between its contacts.
If the temperature sensor is normal, connect a voltmeter to the connector pins and ground.
Turn on the ignition. Set value: about 5 volts. If there is no voltage, ring the wire.
Ring the mass wire.
If the sensor and wires are normal, the control unit is defective.
Withdrawal
Attention: To prevent coolant from flowing out when removing the sensor, drain some of the coolant into a vessel.
Models 316i, 318i
Remove the idle air control valve.
Unbolt intake pipe support and cable duct -arrows-. The temperature sensor is located in the engine block behind these parts.
Remove the temperature sensor connector.
Unscrew temperature sender -1- DME. At a BMW service station, a special tool BMW-00 9160 is used for unscrewing. 2 - coolant temperature sensor for the indicator on the dashboard. The figure shows a six-cylinder engine, the mounting position on a four-cylinder engine is the same.
Installation
Screw in the temperature sensor with a new gasket and tighten to 12-14 Nm.
Attention: Do not overtighten the temperature sensor.
Connect connector. Snap the wire lock.
Fill with coolant and bleed air from the cooling system.
Carry out a test drive and check the tightness of the temperature sensor installation site, if necessary, tighten it a little.