13 62 608 Replacing radiator sensor (N51)

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2013 BMW 128i, 2012 BMW 128i, 2011 BMW 128i, 2010 BMW 128i, and 2009 BMW 128i. However, it is still accessible from the selected car via links, so may be relevant.

WARNING: Scalding hazard!
Only perform this work after engine has cooled down.

WARNING: Poisonous gases!
Only perform this work with a dust extractor.

Necessary preliminary tasks:

Remove fan cowl . See 17 11 035 REMOVING AND INSTALLING/REPLACING FAN COWL WITH ELECTRIC FAN (N51) .

Depiction of radiator sensor:

Sensor pin (1)
Snap hooks (2)

Fig 1: Identifying Snap Hooks And Sensor Pin

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Cut through snap hooks of radiator sensor with a hot appliance (if necessary, soldering iron).

WARNING: Do not inhale the poisonous gases created in the process.
Remove poisonous gases with an air extractor or fan.

IMPORTANT: When cutting through the snap hooks, do not damage the radiator and adjoining components.

Fig 2: Identifying Snap Hooks And Soldering Iron

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Shear off stuck-in sensor pin of radiator sensor (1) by carefully turning housing.

Fig 3: Identifying Radiator Sensor

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Remove cut-off snap hooks.

NOTE: This operation is necessary as otherwise the new sensor cannot be fitted.

Fig 4: Locating Snap Hooks

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Remove contaminants from bores (1 and 2) by blowing clear with compressed air.

In addition, fill bore (1) with suitable degreasing agent, e.g. brake cleaner and wait approx. 1 minute.

Then remove degreasing agent completely from bore (1) by blowing clear with compressed air (bore must be dry).

Fig 5: Identifying Bores

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Clean sensor pin (1) with suitable degreasing agent and a fluff-free cloth.

NOTE:

Sensor pin must be dry before gluing.
Do not touch sensor pin with your fingers after it has been cleaned.
Carry out gluing immediately after cleaning.

Fig 6: Identifying Sensor Pin

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Insert adhesive (Loctite 4204) into bore (1) for sensor pin until adhesive emerges from bore.

If necessary, remove emerging adhesive with a fluff-free cloth.

Bore (1), see also Fig 5.

NOTE:

Adhesive application time: 20 secs.!
Components to be glued must be at room temperature!
Use only Loctite 4204 as adhesive.
Loctite 4204 adhesive is available from any good retailer.
Read and comply with Loctite's Technical Specifications.

Fig 7: Inserting Adhesive Into Bore

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Insert sensor (1) into radiator bores until it snaps audibly into place. Do not tilt sensor in so doing.

NOTE:

Do not expose the sensor to movements or vibrations during the first 30 minutes.
Final strength is achieved after approx. 24 hours.

Fig 8: Inserting Sensor Into Radiator Bores

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NOTE: Read out fault memory of DME control unit.
Clear fault memory